Bump actions/download-artifact from 4 to 5

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 5.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,28 @@
+---
+name: Bug report
+about: Create a new bug report
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+#### For bugs with existing features
+
+- Rule Id (if any, e.g. SC1000):
+- My shellcheck version (`shellcheck --version` or "online"):
+- [ ] The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086)
+- [ ] I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit
+
+#### Here's a snippet or screenshot that shows the problem:
+
+```sh
+#!/bin/sh
+your script here
+```
+
+#### Here's what shellcheck currently says:
+
+
+
+#### Here's what I wanted or expected to see:

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,25 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+#### For new checks and feature suggestions
+- [ ] https://www.shellcheck.net/ (i.e. the latest commit) currently gives no useful warnings about this
+- [ ] I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related
+
+#### Here's a snippet or screenshot that shows a potential problem:
+
+```sh
+#!/bin/sh
+your script here
+```
+
+#### Here's what shellcheck currently says:
+
+
+
+#### Here's what I wanted to see:

.github/dependabot.yml

@@ -0,0 +1,7 @@
+version: 2
+
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"

.github/workflows/build.yml

@@ -1,4 +1,4 @@
-name: Build Lol
+name: Build ShellCheck
 
 # Run this workflow every time a new commit pushed to your repository
 on: push
@@ -15,54 +15,80 @@ jobs:
           sudo apt-get install cabal-install
 
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
-
+        with:
-      - name: Package Source
+          fetch-depth: 0
-        run: |
-          mkdir source
-          cabal sdist
-          mv dist/*.tar.gz source/source.tar.gz
 
       - name: Deduce tags
         run: |
-          exec > source/tags
+          mkdir source
-          echo "latest"
+          echo "latest" > source/tags
           if tag=$(git describe --exact-match --tags)
           then
-            echo "stable"
+            echo "stable" >> source/tags
-            echo "$tag"
+            echo "$tag" >> source/tags
           fi
+          cat source/tags
+
+      - name: Package Source
+        run: |
+          grep "stable" source/tags || ./setgitversion
+          cabal sdist
+          mv dist-newstyle/sdist/*.tar.gz source/source.tar.gz
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: source
           path: source/
 
+  run_tests:
+    name: Run tests
+    needs: package_source
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download artifacts
+        uses: actions/download-artifact@v5
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update && sudo apt-get install ghc cabal-install
+          cabal update
+
+      - name: Unpack source
+        run: |
+          cd source
+          tar xvf source.tar.gz --strip-components=1
+
+      - name: Build and run tests
+        run: |
+          cd source
+          cabal test
+
   build_source:
-    name: Build Source Code
+    name: Build
     needs: package_source
     strategy:
       matrix:
-        build: [linux.x86_64, linux.aarch64, linux.armv6hf, darwin.x86_64, windows.x86_64]
+        build: [linux.x86_64, linux.aarch64, linux.armv6hf, linux.riscv64, darwin.x86_64, darwin.aarch64, windows.x86_64]
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Download artifacts
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v5
 
       - name: Build source
         run: |
           mkdir -p bin
           mkdir -p bin/${{matrix.build}}
-          ( cd bin && ../build/run_builder ../source/source.tar.gz ../build/${{matrix.build}} )
+          ( cd bin && ../builders/run_builder ../source/source.tar.gz ../builders/${{matrix.build}} )
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
-          name: bin
+          name: ${{matrix.build}}.bin
           path: bin/
 
   package_binary:
@@ -71,25 +97,25 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Download artifacts
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v5
 
       - name: Work around GitHub permissions bug
-        run: chmod +x bin/*/shellcheck*
+        run: chmod +x *.bin/*/shellcheck*
 
       - name: Package binaries
         run: |
           export TAGS="$(cat source/tags)"
           mkdir -p deploy
-          cp -r bin/* deploy
+          cp -r *.bin/* deploy
           cd deploy
           ../.prepare_deploy
           rm -rf */ README* LICENSE*
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: deploy
           path: deploy/
@@ -100,11 +126,16 @@ jobs:
     runs-on: ubuntu-latest
     environment: Deploy
     steps:
+      - name: Install Dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install hub
+
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Download artifacts
-        uses: actions/download-artifact@v2
+        uses: actions/download-artifact@v5
 
       - name: Upload to GitHub
         env:
@@ -113,6 +144,10 @@ jobs:
           export TAGS="$(cat source/tags)"
           ./.github_deploy
 
+      - name: Waiting for GitHub to replicate uploaded releases
+        run: |
+          sleep 300
+
       - name: Upload to Docker Hub
         env:
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}

.github_deploy

@@ -26,4 +26,3 @@ do
   done
   gh release upload "$tag" "${files[@]}" --clobber || exit 1
 done
-

.gitignore

@@ -12,6 +12,7 @@ cabal-dev
 .cabal-sandbox/
 cabal.sandbox.config
 cabal.config
+cabal.project.freeze
 .stack-work
 
 ### Snap ###
@@ -20,3 +21,4 @@ cabal.config
 /parts/
 /prime/
 *.snap
+/dist-newstyle/

.multi_arch_docker

@@ -3,28 +3,10 @@
 # binaries previously built and deployed to GitHub.
 
 function multi_arch_docker::install_docker_buildx() {
-  # Install up-to-date version of docker, with buildx support.
-  local -r docker_apt_repo='https://download.docker.com/linux/ubuntu'
-  curl -fsSL "${docker_apt_repo}/gpg" | sudo apt-key add -
-  local -r os="$(lsb_release -cs)"
-  sudo add-apt-repository "deb [arch=amd64] $docker_apt_repo $os stable"
-  sudo apt-get update
-  sudo apt-get -y -o Dpkg::Options::="--force-confnew" install docker-ce
-
-  # Enable docker daemon experimental support (for 'pull --platform').
-  local -r config='/etc/docker/daemon.json'
-  if [[ -e "$config" ]]; then
-    sudo sed -i -e 's/{/{ "experimental": true, /' "$config"
-  else
-    echo '{ "experimental": true }' | sudo tee "$config"
-  fi
-  sudo systemctl restart docker
-
   # Install QEMU multi-architecture support for docker buildx.
   docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
 
   # Instantiate docker buildx builder with multi-architecture support.
-  export DOCKER_CLI_EXPERIMENTAL=enabled
   docker buildx create --name mybuilder
   docker buildx use mybuilder
   # Start up buildx and verify that all is OK.
@@ -98,6 +80,7 @@ function multi_arch_docker::main() {
   export DOCKER_PLATFORMS='linux/amd64'
   DOCKER_PLATFORMS+=' linux/arm64'
   DOCKER_PLATFORMS+=' linux/arm/v6'
+  DOCKER_PLATFORMS+=' linux/riscv64'
 
   multi_arch_docker::install_docker_buildx
   multi_arch_docker::login_to_docker_hub

.snapsquid.conf

@@ -1,14 +0,0 @@
-# In 2015, cabal-install had a http bug triggered when proxies didn't keep
-# the connection open. This version made it into Ubuntu Xenial as used by
-# Snapcraft. In June 2018, Snapcraft's proxy started triggering this bug.
-#
-#     https://bugs.launchpad.net/launchpad-buildd/+bug/1797809
-#
-# Workaround: add more proxy
-
-visible_hostname localhost
-http_port 8888
-cache_peer 10.10.10.1 parent 8222 0 no-query default
-cache_peer_domain localhost !.internal
-http_access allow all
-

CHANGELOG.md

@@ -1,13 +1,138 @@
 ## Git
 ### Added
+
+### Changed
+
+### Fixed
+
+### Removed
+
+
+## v0.11.0 - 2025-08-03
+### Added
+- SC2327/SC2328: Warn about capturing the output of redirected commands.
+- SC2329: Warn when (non-escaping) functions are never invoked.
+- SC2330: Warn about unsupported glob matches with [[ .. ]] in BusyBox.
+- SC2331: Suggest using standard -e instead of unary -a in tests.
+- SC2332: Warn about `[ ! -o opt ]` being unconditionally true in Bash.
+- SC3062: Warn about bashism `[ -o opt ]`.
+- Optional `avoid-negated-conditions`: suggest replacing `[ ! a -eq b ]`
+  with `[ a -ne b ]`, and similar for -ge/-lt/=/!=/etc (SC2335).
+- Precompiled binaries for Linux riscv64 (linux.riscv64)
+
+### Changed
+- SC2002 about Useless Use Of Cat is now disabled by default. It can be
+  re-enabled with `--enable=useless-use-of-cat` or equivalent directive.
+- SC2236/SC2237 about replacing `[ ! -n .. ]` with `[ -z ]` and vice versa
+  is now optional under `avoid-negated-conditions`.
+- SC2015 about `A && B || C` no longer triggers when B is a test command.
+- SC3012: Do not warn about `\<` and `\>` in test/[] as specified in POSIX.1-2024
+- Diff output now uses / as path separator on Windows
+
+### Fixed
+- SC2218 about function use-before-define is now more accurate.
+- SC2317 about unreachable commands is now less spammy for nested ones.
+- SC2292, optional suggestion for [[ ]], now triggers for Busybox.
+- Updates for Bash 5.3, including `${| cmd; }` and `source -p`
+
+### Removed
+- SC3013: removed since the operators `-ot/-nt/-ef` are specified in POSIX.1-2024
+
+
+## v0.10.0 - 2024-03-07
+### Added
+- Precompiled binaries for macOS ARM64 (darwin.aarch64)
+- Added support for busybox sh
+- Added flag --rcfile to specify an rc file by name.
+- Added `extended-analysis=true` directive to enable/disable dataflow analysis
+  (with a corresponding --extended-analysis flag).
+- SC2324: Warn when x+=1 appends instead of increments
+- SC2325: Warn about multiple `!`s in dash/sh.
+- SC2326: Warn about `foo | ! bar` in bash/dash/sh.
+- SC3012: Warn about lexicographic-compare bashism in test like in [ ]
+- SC3013: Warn bashism `test _ -op/-nt/-ef _` like in [ ]
+- SC3014: Warn bashism `test _ == _` like in [ ]
+- SC3015: Warn bashism `test _ =~ _` like in [ ]
+- SC3016: Warn bashism `test -v _` like in [ ]
+- SC3017: Warn bashism `test -a _` like in [ ]
+
+### Fixed
+- source statements with here docs now work correctly
+- "(Array.!): undefined array element" error should no longer occur
+
+
+## v0.9.0 - 2022-12-12
+### Added
+- SC2316: Warn about 'local readonly foo' and similar (thanks, patrickxia!)
+- SC2317: Warn about unreachable commands
+- SC2318: Warn about backreferences in 'declare x=1 y=$x'
+- SC2319/SC2320: Warn when $? refers to echo/printf/[ ]/[[ ]]/test
+- SC2321: Suggest removing $((..)) in array[$((idx))]=val
+- SC2322: Suggest collapsing double parentheses in arithmetic contexts
+- SC2323: Suggest removing wrapping parentheses in a[(x+1)]=val
+
+### Fixed
+- SC2086: Now uses DFA to make more accurate predictions about values
+- SC2086: No longer warns about values declared as integer with declare -i
+
+### Changed
+- ShellCheck now has a Data Flow Analysis engine to make smarter decisions
+  based on control flow rather than just syntax. Existing checks will
+  gradually start using it, which may cause them to trigger differently
+  (but more accurately).
+- Values in directives/shellcheckrc can now be quoted with '' or ""
+
+
+## v0.8.0 - 2021-11-06
+### Added
+- `disable=all` now conveniently disables all warnings
+- `external-sources=true` directive can be added to .shellcheckrc to make
+  shellcheck behave as if `-x` was specified.
+- Optional `check-extra-masked-returns` for pointing out commands with
+  suppressed exit codes (SC2312).
+- Optional `require-double-brackets` for recommending \[\[ ]] (SC2292).
+- SC2286-SC2288: Warn when command name ends in a symbol like `/.)'"`
+- SC2289: Warn when command name contains tabs or linefeeds
+- SC2291: Warn about repeated unquoted spaces between words in echo
+- SC2292: Suggest [[ over [ in Bash/Ksh scripts (optional)
+- SC2293/SC2294: Warn when calling `eval` with arrays
+- SC2295: Warn about "${x#$y}" treating $y as a pattern when not quoted
+- SC2296-SC2301: Improved warnings for bad parameter expansions
+- SC2302/SC2303: Warn about loops over array values when using them as keys
+- SC2304-SC2306: Warn about unquoted globs in expr arguments
+- SC2307: Warn about insufficient number of arguments to expr
+- SC2308: Suggest other approaches for non-standard expr extensions
+- SC2313: Warn about `read` with unquoted, array indexed variable
+
+### Fixed
+- SC2102 about repetitions in ranges no longer triggers on [[ -v arr[xx] ]]
+- SC2155 now recognizes `typeset` and local read-only `declare` statements
+- SC2181 now tries to avoid triggering for error handling functions
+- SC2290: Warn about misused = in declare & co, which were not caught by SC2270+
+- The flag --color=auto no longer outputs color when TERM is "dumb" or unset
+
+### Changed
+- SC2048: Warning about $\* now also applies to ${array[\*]}
+- SC2181 now only triggers on single condition tests like `[ $? = 0 ]`.
+- Quote warnings are now emitted for declaration utilities in sh
+- Leading `_` can now be used to suppress warnings about unused variables
+- TTY output now includes warning level in text as well as color
+
+### Removed
+- SC1004: Literal backslash+linefeed in '' was found to be usually correct
+
+
+## v0.7.2 - 2021-04-19
+### Added
 - `disable` directives can now be a range, e.g. `disable=SC3000-SC4000`
+- SC1143: Warn about line continuations in comments
 - SC2259/SC2260: Warn when redirections override pipes
 - SC2261: Warn about multiple competing redirections
 - SC2262/SC2263: Warn about aliases declared and used in the same parsing unit
 - SC2264: Warn about wrapper functions that blatantly recurse
 - SC2265/SC2266: Warn when using & or | with test statements
 - SC2267: Warn when using xargs -i instead of -I
-- Optional avoid-x-comparisons: Style warning SC2268 for `[ x$var = xval ]`
+- SC2268: Warn about unnecessary x-comparisons like `[ x$var = xval ]`
 
 ### Fixed
 - SC1072/SC1073 now respond to disable annotations, though ignoring parse errors
@@ -21,7 +146,7 @@
 - POSIX/dash unsupported feature warnings now have individual SC3xxx codes
 - SC1090: A leading `$x/` or `$(x)/` is now treated as `./` when locating files
 - SC2154: Variables appearing in -z/-n tests are no longer considered unassigned
-- SC2270-SC2285: Improved warnings about misused =, e.g. `${var}=42`
+- SC2270-SC2285: Improved warnings about misused `=`, e.g. `${var}=42`
 
 
 ## v0.7.1 - 2020-04-04
@@ -164,7 +289,7 @@
 - SC2204/SC2205: Warn about `( -z foo )` and `( foo -eq bar )`
 - SC2200/SC2201: Warn about brace expansion in [/[[
 - SC2198/SC2199: Warn about arrays in [/[[
-- SC2196/SC2197: Warn about deprected egrep/fgrep
+- SC2196/SC2197: Warn about deprecated egrep/fgrep
 - SC2195: Warn about unmatchable case branches
 - SC2194: Warn about constant 'case' statements
 - SC2193: Warn about `[[ file.png == *.mp3 ]]` and other unmatchables
@@ -181,7 +306,7 @@
 ### Fixed
 - `-c` no longer suggested when using `grep -o | wc`
 - Comments and whitespace are now allowed before filewide directives
-- Here doc delimters with esoteric quoting like `foo""` are now handled
+- Here doc delimiters with esoteric quoting like `foo""` are now handled
 - SC2095 about `ssh` in while read loops is now suppressed when using `-n`
 - `%(%Y%M%D)T` now recognized as a single formatter in `printf` checks
 - `grep -F` now suppresses regex related suggestions

Dockerfile.multi-arch

@@ -5,17 +5,15 @@ ARG tag
 
 # Put the right binary for each architecture into place for the
 # multi-architecture docker image.
+ARG url_base="https://github.com/koalaman/shellcheck/releases/download/"
 RUN set -x; \
   arch="$(uname -m)"; \
   echo "arch is $arch"; \
   if [ "${arch}" = 'armv7l' ]; then \
     arch='armv6hf'; \
   fi; \
-  url_base='https://github.com/koalaman/shellcheck/releases/download/'; \
   tar_file="${tag}/shellcheck-${tag}.linux.${arch}.tar.xz"; \
-  wget "${url_base}${tar_file}" -O - | tar xJf -; \
+  wget "${url_base}${tar_file}" -O - | tar -C /bin --strip-components=1 -xJf - "shellcheck-${tag}/shellcheck" && \
-  mv "shellcheck-${tag}/shellcheck" /bin/; \
-  rm -rf "shellcheck-${tag}"; \
   ls -laF /bin/shellcheck
 
 # ShellCheck image

LICENSE

@@ -1,13 +1,3 @@
-Employer mandated disclaimer:
-
-  I am providing code in the repository to you under an open source license.
-  Because this is my personal repository, the license you receive to my code is
-  from me and other individual contributors, and not my employer (Facebook).
-
-  - Vidar "koala_man" Holen
-
-----
-
                     GNU GENERAL PUBLIC LICENSE
                        Version 3, 29 June 2007
 
@@ -681,4 +671,4 @@ into proprietary programs.  If your program is a subroutine library, you
 may consider it more useful to permit linking proprietary applications with
 the library.  If this is what you want to do, use the GNU Lesser General
 Public License instead of this License.  But first, please read
-<https://www.gnu.org/philosophy/why-not-lgpl.html>.
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

README.md

@@ -1,4 +1,5 @@
-[![Build Status](https://travis-ci.org/koalaman/shellcheck.svg?branch=master)](https://travis-ci.org/koalaman/shellcheck)
+[![Build Status](https://github.com/koalaman/shellcheck/actions/workflows/build.yml/badge.svg)](https://github.com/koalaman/shellcheck/actions/workflows/build.yml)
+
 
 # ShellCheck - A shell script static analysis tool
 
@@ -76,7 +77,7 @@ You can see ShellCheck suggestions directly in a variety of editors.
 
 * Sublime, through [SublimeLinter](https://github.com/SublimeLinter/SublimeLinter-shellcheck).
 
-* Atom, through [Linter](https://github.com/AtomLinter/linter-shellcheck).
+* Pulsar Edit (former Atom), through [linter-shellcheck-pulsar](https://github.com/pulsar-cooperative/linter-shellcheck-pulsar).
 
 * VSCode, through [vscode-shellcheck](https://github.com/timonwong/vscode-shellcheck).
 
@@ -109,12 +110,11 @@ Services and platforms that have ShellCheck pre-installed and ready to use:
 * [Codacy](https://www.codacy.com/)
 * [Code Climate](https://codeclimate.com/)
 * [Code Factor](https://www.codefactor.io/)
+* [Codety](https://www.codety.io/) via the [Codety Scanner](https://github.com/codetyio/codety-scanner)
 * [CircleCI](https://circleci.com) via the [ShellCheck Orb](https://circleci.com/orbs/registry/orb/circleci/shellcheck)
 * [Github](https://github.com/features/actions) (only Linux)
-
+* [Trunk Code Quality](https://trunk.io/code-quality) (universal linter; [allows you to explicitly version your shellcheck install](https://github.com/trunk-io/plugins/blob/bcbb361dcdbe4619af51ea7db474d7fb87540d20/.trunk/trunk.yaml#L32)) via the [shellcheck plugin](https://github.com/trunk-io/plugins/blob/main/linters/shellcheck/plugin.yaml)
-Services and platforms with third party plugins:
+* [CodeRabbit](https://coderabbit.ai/)
-
-* [SonarQube](https://www.sonarqube.org/) through [sonar-shellcheck-plugin](https://github.com/emerald-squad/sonar-shellcheck-plugin)
 
 Most other services, including [GitLab](https://about.gitlab.com/), let you install
 ShellCheck yourself, either through the system's package manager (see [Installing](#installing)),
@@ -143,7 +143,7 @@ On systems with Stack (installs to `~/.local/bin`):
 
 On Debian based distros:
 
-    apt-get install shellcheck
+    sudo apt install shellcheck
 
 On Arch Linux based distros:
 
@@ -157,8 +157,8 @@ On Gentoo based distros:
 
 On EPEL based distros:
 
-    yum -y install epel-release
+    sudo yum -y install epel-release
-    yum install ShellCheck
+    sudo yum install ShellCheck
 
 On Fedora based distros:
 
@@ -196,6 +196,12 @@ On Windows (via [chocolatey](https://chocolatey.org/packages/shellcheck)):
 C:\> choco install shellcheck
 ```
 
+Or Windows (via [winget](https://github.com/microsoft/winget-pkgs)):
+
+```cmd
+C:\> winget install --id koalaman.shellcheck
+```
+
 Or Windows (via [scoop](http://scoop.sh)):
 
 ```cmd
@@ -224,17 +230,26 @@ Using the [nix package manager](https://nixos.org/nix):
 nix-env -iA nixpkgs.shellcheck
 ```
 
+Using the [Flox package manager](https://flox.dev/)
+```sh
+flox install shellcheck
+```
+
 Alternatively, you can download pre-compiled binaries for the latest release here:
 
 * [Linux, x86_64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.x86_64.tar.xz) (statically linked)
 * [Linux, armv6hf](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.armv6hf.tar.xz), i.e. Raspberry Pi (statically linked)
 * [Linux, aarch64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.aarch64.tar.xz) aka ARM64 (statically linked)
+* [macOS, aarch64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.darwin.aarch64.tar.xz)
 * [macOS, x86_64](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.darwin.x86_64.tar.xz)
 * [Windows, x86](https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.zip)
 
 or see the [GitHub Releases](https://github.com/koalaman/shellcheck/releases) for other releases
 (including the [latest](https://github.com/koalaman/shellcheck/releases/tag/latest) meta-release for daily git builds).
 
+There are currently no official binaries for Apple Silicon, but third party builds are available via
+[ShellCheck for Visual Studio Code](https://github.com/vscode-shellcheck/shellcheck-binaries/releases).
+
 Distro packages already come with a `man` page. If you are building from source, it can be installed with:
 
 ```console
@@ -242,6 +257,19 @@ pandoc -s -f markdown-smart -t man shellcheck.1.md -o shellcheck.1
 sudo mv shellcheck.1 /usr/share/man/man1
 ```
 
+### pre-commit
+
+To run ShellCheck via [pre-commit](https://pre-commit.com/), add the hook to your `.pre-commit-config.yaml`:
+
+```
+repos:
+-   repo: https://github.com/koalaman/shellcheck-precommit
+    rev: v0.7.2
+    hooks:
+    -   id: shellcheck
+#       args: ["--severity=warning"]  # Optionally only show errors and warnings
+```
+
 ### Travis CI
 
 Travis CI has now integrated ShellCheck by default, so you don't need to manually install it.
@@ -289,10 +317,6 @@ Verify that `cabal` is installed and update its dependency list with
 
     $ cabal install
 
-Or if you intend to run the tests:
-
-    $ cabal install --enable-tests
-
 This will compile ShellCheck and install it to your `~/.cabal/bin` directory.
 
 Add this directory to your `PATH` (for bash, add this to your `~/.bashrc`):
@@ -348,6 +372,7 @@ echo 'Don't forget to restart!'   # Singlequote closed by apostrophe
 echo 'Don\'t try this at home'    # Attempting to escape ' in ''
 echo 'Path is $PATH'              # Variables in single quotes
 trap "echo Took ${SECONDS}s" 0    # Prematurely expanded trap
+unset var[i]                      # Array index treated as glob
 ```
 
 ### Conditionals
@@ -366,6 +391,7 @@ ShellCheck can recognize many types of incorrect test statements.
 [ grep -q foo file ]              # Command without $(..)
 [[ "$$file" == *.jpg ]]           # Comparisons that can't succeed
 (( 1 -lt 2 ))                     # Using test operators in ((..))
+[ x ] & [ y ] | [ z ]             # Accidental backgrounding and piping
 ```
 
 ### Frequently misused commands
@@ -437,6 +463,8 @@ echo "Hello $name"                # Unassigned lowercase variables
 cmd | read bar; echo $bar         # Assignments in subshells
 cat foo | cp bar                  # Piping to commands that don't read
 printf '%s: %s\n' foo             # Mismatches in printf argument count
+eval "${array[@]}"                # Lost word boundaries in array eval
+for i in "${x[@]}"; do ${x[$i]}   # Using array value as key
 ```
 
 ### Robustness
@@ -461,6 +489,7 @@ ShellCheck will warn when using features not supported by the shebang. For examp
 echo {1..$n}                     # Works in ksh, but not bash/dash/sh
 echo {1..10}                     # Works in ksh and bash, but not dash/sh
 echo -n 42                       # Works in ksh, bash and dash, undefined in sh
+expr match str regex             # Unportable alias for `expr str : regex`
 trap 'exit 42' sigint            # Unportable signal spec
 cmd &> file                      # Unportable redirection operator
 read foo < /dev/tcp/host/22      # Unportable intercepted files
@@ -481,10 +510,15 @@ rm “file”                         # Unicode quotes
 echo "Hello world"                # Carriage return / DOS line endings
 echo hello \                      # Trailing spaces after \
 var=42 echo $var                  # Expansion of inlined environment
-#!/bin/bash -x -e                 # Common shebang errors
+!# bin/bash -x -e                 # Common shebang errors
 echo $((n/180*100))               # Unnecessary loss of precision
 ls *[:digit:].txt                 # Bad character class globs
 sed 's/foo/bar/' file > file      # Redirecting to input
+var2=$var2                        # Variable assigned to itself
+[ x$var = xval ]                  # Antiquated x-comparisons
+ls() { ls -l "$@"; }              # Infinitely recursive wrapper
+alias ls='ls -l'; ls foo          # Alias used before it takes effect
+for x; do for x; do               # Nested loop uses same variable
 while getopts "a" f; do case $f in "b") # Unhandled getopts flags
 ```
 
@@ -528,4 +562,3 @@ Happy ShellChecking!
 
 * The wiki has [long form descriptions](https://github.com/koalaman/shellcheck/wiki/Checks) for each warning, e.g. [SC2221](https://github.com/koalaman/shellcheck/wiki/SC2221).
 * ShellCheck does not attempt to enforce any kind of formatting or indenting style, so also check out [shfmt](https://github.com/mvdan/sh)!
-

ShellCheck.cabal

@@ -1,5 +1,5 @@
 Name:             ShellCheck
-Version:          0.7.1
+Version:          0.11.0
 Synopsis:         Shell script analysis tool
 License:          GPL-3
 License-file:     LICENSE
@@ -8,7 +8,7 @@ Author:           Vidar Holen
 Maintainer:       vidar@vidarholen.net
 Homepage:         https://www.shellcheck.net/
 Build-Type:       Simple
-Cabal-Version:    >= 1.8
+Cabal-Version:    1.18
 Bug-reports:      https://github.com/koalaman/shellcheck/issues
 Description:
   The goals of ShellCheck are:
@@ -22,9 +22,11 @@ Description:
   * To point out subtle caveats, corner cases and pitfalls, that may cause an
     advanced user's otherwise working script to fail under future circumstances.
 
+Extra-Doc-Files:
+    README.md
+    CHANGELOG.md
 Extra-Source-Files:
     -- documentation
-    README.md
     shellcheck.1.md
     -- A script to build the man page using pandoc
     manpage
@@ -43,19 +45,26 @@ library
       build-depends:
         semigroups
     build-depends:
-      aeson,
+      -- The lower bounds are based on GHC 7.10.3
-      array,
+      -- The upper bounds are based on GHC 9.12.1
-      base >= 4.8.0.0 && < 5,
+      aeson                >= 1.4.0 && < 2.3,
-      bytestring,
+      array                >= 0.5.1 && < 0.6,
-      containers >= 0.5,
+      base                 >= 4.8.0.0 && < 5,
-      deepseq >= 1.4.0.0,
+      bytestring           >= 0.10.6 && < 0.13,
-      Diff >= 0.2.0,
+      containers           >= 0.5.6 && < 0.9,
-      directory >= 1.2.3.0,
+      deepseq              >= 1.4.1 && < 1.6,
-      mtl >= 2.2.1,
+      Diff                 >= 0.4.0 && < 1.1,
-      filepath,
+      fgl                  (>= 5.7.0 && < 5.8.1.0) || (>= 5.8.1.1 && < 5.9),
-      parsec,
+      filepath             >= 1.4.0 && < 1.6,
-      regex-tdfa,
+      mtl                  >= 2.2.2 && < 2.4,
-      QuickCheck >= 2.7.4,
+      parsec               >= 3.1.14 && < 3.2,
+      QuickCheck           >= 2.14.2 && < 2.17,
+      regex-tdfa           >= 1.2.0 && < 1.4,
+      transformers         >= 0.4.2 && < 0.7,
+
+      -- getXdgDirectory from 1.2.3.0
+      directory            >= 1.2.3 && < 1.4,
+
       -- When cabal supports it, move this to setup-depends:
       process
     exposed-modules:
@@ -64,11 +73,15 @@ library
       ShellCheck.Analytics
       ShellCheck.Analyzer
       ShellCheck.AnalyzerLib
+      ShellCheck.CFG
+      ShellCheck.CFGAnalysis
       ShellCheck.Checker
       ShellCheck.Checks.Commands
+      ShellCheck.Checks.ControlFlow
       ShellCheck.Checks.Custom
       ShellCheck.Checks.ShellSupport
       ShellCheck.Data
+      ShellCheck.Debug
       ShellCheck.Fixer
       ShellCheck.Formatter.Format
       ShellCheck.Formatter.CheckStyle
@@ -80,9 +93,11 @@ library
       ShellCheck.Formatter.Quiet
       ShellCheck.Interface
       ShellCheck.Parser
+      ShellCheck.Prelude
       ShellCheck.Regex
     other-modules:
       Paths_ShellCheck
+    default-language: Haskell98
 
 executable shellcheck
     if impl(ghc < 8.0)
@@ -91,18 +106,21 @@ executable shellcheck
     build-depends:
       aeson,
       array,
-      base >= 4 && < 5,
+      base,
       bytestring,
       containers,
-      deepseq >= 1.4.0.0,
+      deepseq,
-      Diff >= 0.2.0,
+      Diff,
-      directory >= 1.2.3.0,
+      directory,
-      mtl >= 2.2.1,
+      fgl,
+      mtl,
       filepath,
-      parsec >= 3.0,
+      parsec,
-      QuickCheck >= 2.7.4,
+      QuickCheck,
       regex-tdfa,
+      transformers,
       ShellCheck
+    default-language: Haskell98
     main-is: shellcheck.hs
 
 test-suite test-shellcheck
@@ -110,17 +128,19 @@ test-suite test-shellcheck
     build-depends:
       aeson,
       array,
-      base >= 4 && < 5,
+      base,
       bytestring,
       containers,
-      deepseq >= 1.4.0.0,
+      deepseq,
-      Diff >= 0.2.0,
+      Diff,
-      directory >= 1.2.3.0,
+      directory,
-      mtl >= 2.2.1,
+      fgl,
       filepath,
+      mtl,
       parsec,
-      QuickCheck >= 2.7.4,
+      QuickCheck,
       regex-tdfa,
+      transformers,
       ShellCheck
+    default-language: Haskell98
     main-is: test/shellcheck.hs
-

build/darwin.x86_64/Dockerfile

@@ -1,31 +0,0 @@
-# DIGEST:sha256:fa32af4677e2860a1c5950bc8c360f309e2a87e2ddfed27b642fddf7a6093b76
-FROM liushuyu/osxcross:latest
-
-ENV TARGET x86_64-apple-darwin18
-ENV TARGETNAME darwin.x86_64
-
-# Build dependencies
-USER root
-ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get update && apt-get install -y ghc automake autoconf llvm curl
-
-# Build GHC
-WORKDIR /ghc
-RUN curl -L "https://downloads.haskell.org/~ghc/8.10.4/ghc-8.10.4-src.tar.xz" | tar xJ --strip-components=1
-RUN ./boot && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
-RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
-RUN make install
-RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/cabal-install-3.2.0.0-x86_64-unknown-linux.tar.xz" | tar xJv -C /usr/local/bin
-
-# Due to an apparent cabal bug, we specify our options directly to cabal
-# It won't reuse caches if ghc-options are specified in ~/.cabal/config
-ENV CABALOPTS "--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg"
-
-# Prebuild the dependencies
-RUN cabal update && IFS=';' && cabal install $CABALOPTS --lib Diff-0.4.0 base-compat-0.11.2 base-orphans-0.8.4 dlist-1.0 hashable-1.3.0.0 indexed-traversable-0.1.1 integer-logarithms-1.0.3.1 primitive-0.7.1.0 regex-base-0.94.0.0 splitmix-0.1.0.3 tagged-0.8.6.1 th-abstraction-0.4.2.0 transformers-compat-0.6.6 base-compat-batteries-0.11.2 time-compat-1.9.5 unordered-containers-0.2.13.0 data-fix-0.3.1 vector-0.12.2.0 scientific-0.3.6.2 regex-tdfa-1.3.1.0 random-1.2.0 distributive-0.6.2.1 attoparsec-0.13.2.5 uuid-types-1.0.3 comonad-5.0.8 bifunctors-5.5.10 assoc-1.0.2 these-1.1.1.1 strict-0.4.0.1 aeson-1.5.5.1
-
-# Copy the build script
-COPY build /usr/bin
-
-WORKDIR /scratch
-ENTRYPOINT ["/usr/bin/build"]

build/linux.aarch64/Dockerfile

@@ -1,30 +0,0 @@
-FROM ubuntu:20.04
-
-ENV TARGET aarch64-linux-gnu
-ENV TARGETNAME linux.aarch64
-
-# Build dependencies
-USER root
-ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get update && apt-get install -y ghc automake autoconf build-essential llvm curl qemu-user-static gcc-$TARGET
-
-# Build GHC
-WORKDIR /ghc
-RUN curl -L "https://downloads.haskell.org/~ghc/8.10.4/ghc-8.10.4-src.tar.xz" | tar xJ --strip-components=1
-RUN ./boot && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
-RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
-RUN make install
-RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/cabal-install-3.2.0.0-x86_64-unknown-linux.tar.xz" | tar xJv -C /usr/local/bin
-
-# Due to an apparent cabal bug, we specify our options directly to cabal
-# It won't reuse caches if ghc-options are specified in ~/.cabal/config
-ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections;--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg"
-
-# Prebuild the dependencies
-RUN cabal update && IFS=';' && cabal install $CABALOPTS --lib Diff-0.4.0 base-compat-0.11.2 base-orphans-0.8.4 dlist-1.0 hashable-1.3.0.0 indexed-traversable-0.1.1 integer-logarithms-1.0.3.1 primitive-0.7.1.0 regex-base-0.94.0.0 splitmix-0.1.0.3 tagged-0.8.6.1 th-abstraction-0.4.2.0 transformers-compat-0.6.6 base-compat-batteries-0.11.2 time-compat-1.9.5 unordered-containers-0.2.13.0 data-fix-0.3.1 vector-0.12.2.0 scientific-0.3.6.2 regex-tdfa-1.3.1.0 random-1.2.0 distributive-0.6.2.1 attoparsec-0.13.2.5 uuid-types-1.0.3 comonad-5.0.8 bifunctors-5.5.10 assoc-1.0.2 these-1.1.1.1 strict-0.4.0.1 aeson-1.5.5.1
-
-# Copy the build script
-COPY build /usr/bin
-
-WORKDIR /scratch
-ENTRYPOINT ["/usr/bin/build"]

build/linux.armv6hf/Dockerfile

@@ -1,59 +0,0 @@
-# I've again spent days trying to get a working armv6hf compiler going.
-# God only knows how many recompilations of GCC, GHC, libraries, and
-# ShellCheck itself, has gone into it.
-#
-# I tried Debian's toolchain.  I tried my custom one built according to
-# RPi `gcc -v`. I tried GHC9, glibc, musl, registerised vs not, but
-# nothing has yielded an armv6hf binary that does not immediately
-# segfault on qemu-arm-static or the RPi itself.
-#
-# I then tried the same but with armv7hf. Same story.
-#
-# Emulating the entire userspace with balenalib again?  Very strange build
-# failures where programs would fail to execute with > ~100 arguments.
-#
-# Finally, creating our own appears to work when using a custom QEmu
-# patched to follow execve calls.
-#
-# PS: $100 bounty for getting a RPi1 compatible static build going
-#     with cross-compilation, similar to what the aarch64 build does.
-#
-
-FROM ubuntu:20.04
-
-ENV TARGETNAME linux.armv6hf
-
-# Build QEmu with execve follow support
-USER root
-ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get update
-RUN apt-get install -y build-essential git ninja-build python3 pkg-config libglib2.0-dev libpixman-1-dev
-WORKDIR /build
-RUN git clone --depth 1 https://github.com/koalaman/qemu
-RUN cd qemu && ./configure --static && cd build && ninja qemu-arm
-RUN cp qemu/build/qemu-arm /build/qemu-arm-static
-ENV QEMU_EXECVE 1
-
-# Set up an armv6 userspace
-WORKDIR /
-RUN apt-get install -y debootstrap qemu-user-static
-# We expect this to fail if the host doesn't have binfmt qemu support
-RUN qemu-debootstrap --arch armhf bullseye pi http://mirrordirector.raspbian.org/raspbian || [ -e /pi/etc/issue ]
-RUN cp /build/qemu-arm-static /pi/usr/bin/qemu-arm-static
-RUN printf > /bin/pirun '%s\n' '#!/bin/sh' 'chroot /pi /usr/bin/qemu-arm-static /usr/bin/env "$@"' && chmod +x /bin/pirun
-# If the debootstrap process didn't finish, continue it
-RUN [ ! -e /pi/debootstrap ] || pirun '/debootstrap/debootstrap' --second-stage
-
-# Install deps in the chroot
-RUN pirun apt-get update
-RUN pirun apt-get install -y ghc cabal-install
-
-# Finally we can build the current dependencies. This takes hours.
-ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections;--gcc-options;-Os -Wl,--gc-sections -ffunction-sections -fdata-sections"
-RUN pirun cabal update
-RUN IFS=";" && pirun cabal install --lib $CABALOPTS Diff-0.4.0 base-compat-0.11.2 base-orphans-0.8.4 dlist-1.0 hashable-1.3.1.0 indexed-traversable-0.1.1 integer-logarithms-1.0.3.1 primitive-0.7.1.0 regex-base-0.94.0.1 splitmix-0.1.0.3 tagged-0.8.6.1 th-abstraction-0.4.2.0 transformers-compat-0.6.6 base-compat-batteries-0.11.2 time-compat-1.9.5 unordered-containers-0.2.13.0 data-fix-0.3.1 vector-0.12.2.0 scientific-0.3.6.2 regex-tdfa-1.3.1.0 random-1.2.0 distributive-0.6.2.1 attoparsec-0.13.2.5 uuid-types-1.0.4 comonad-5.0.8 bifunctors-5.5.10 assoc-1.0.2 these-1.1.1.1 strict-0.4.0.1 aeson-1.5.6.0
-
-# Copy the build script
-WORKDIR /pi/scratch
-COPY build /pi/usr/bin
-ENTRYPOINT ["/bin/pirun", "/usr/bin/build"]

build/linux.x86_64/Dockerfile

@@ -1,26 +0,0 @@
-FROM ubuntu:20.04
-
-ENV TARGETNAME linux.x86_64
-
-# Install GHC and cabal
-USER root
-ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get update && apt-get install -y ghc curl xz-utils
-
-# So we'd like a later version of Cabal that supports --enable-executable-static,
-# but we can't use Ubuntu 20.10 because coreutils has switched to new syscalls that
-# the TravisCI kernel doesn't support. Download it manually.
-RUN curl "https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/cabal-install-3.2.0.0-x86_64-unknown-linux.tar.xz" | tar xJv -C /usr/bin
-
-# Use ld.bfd instead of ld.gold due to
-# x86_64-linux-gnu/libpthread.a(pthread_cond_init.o)(.note.stapsdt+0x14): error:
-#    relocation refers to local symbol "" [2], which is defined in a discarded section
-ENV CABALOPTS "--ghc-options;-optl-Wl,-fuse-ld=bfd -split-sections -optc-Os -optc-Wl,--gc-sections"
-
-# Other archs pre-build dependencies here, but this one doesn't to detect ecosystem movement
-
-# Copy the build script
-COPY build /usr/bin
-
-WORKDIR /scratch
-ENTRYPOINT ["/usr/bin/build"]

build/windows.x86_64/Dockerfile

@@ -1,27 +0,0 @@
-FROM ubuntu:20.04
-
-ENV TARGETNAME windows.x86_64
-
-# We don't need wine32, even though it complains
-USER root
-ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get update && apt-get install -y curl busybox wine
-
-# Fetch Windows version, will be available under z:\haskell
-WORKDIR /haskell
-RUN curl -L "https://downloads.haskell.org/~ghc/8.10.4/ghc-8.10.4-x86_64-unknown-mingw32.tar.xz" | tar xJ --strip-components=1
-WORKDIR /haskell/bin
-RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/cabal-install-3.2.0.0-x86_64-unknown-mingw32.zip" | busybox unzip -
-RUN curl -L "https://curl.se/windows/dl-7.75.0/curl-7.75.0-win64-mingw.zip" | busybox unzip - && mv curl-7.75.0-win64-mingw/bin/* .
-ENV WINEPATH /haskell/bin
-
-# It's unknown whether Cabal on Windows suffers from the same issue
-# that necessitated this but I don't care enough to find out
-ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections"
-
-# Precompile some deps to speed up later builds. This list is just copied from `cabal build`
-RUN wine /haskell/bin/cabal.exe update && IFS=';' && wine /haskell/bin/cabal.exe install $CABALOPTS --lib Diff-0.4.0 base-compat-0.11.2 base-orphans-0.8.4 dlist-1.0 hashable-1.3.0.0 indexed-traversable-0.1.1 integer-logarithms-1.0.3.1 primitive-0.7.1.0 regex-base-0.94.0.0 splitmix-0.1.0.3 tagged-0.8.6.1 th-abstraction-0.4.2.0 transformers-compat-0.6.6 base-compat-batteries-0.11.2 time-compat-1.9.5 unordered-containers-0.2.13.0 data-fix-0.3.1 vector-0.12.2.0 scientific-0.3.6.2 regex-tdfa-1.3.1.0 random-1.2.0 distributive-0.6.2.1 attoparsec-0.13.2.5 uuid-types-1.0.3 comonad-5.0.8 bifunctors-5.5.10 assoc-1.0.2 these-1.1.1.1 strict-0.4.0.1 aeson-1.5.5.1
-
-COPY build /usr/bin
-WORKDIR /scratch
-ENTRYPOINT ["/usr/bin/build"]

builders/README.md

@@ -11,3 +11,7 @@ This makes it simple to build any release without exotic hardware or software.
 
 An image can be built and tagged using `build_builder`,
 and run on a source tarball using `run_builder`.
+
+Tip: Are you developing an image that relies on QEmu usermode emulation?
+     It's easy to accidentally depend on binfmt\_misc on the host OS.
+     Do a `echo 0 | sudo tee /proc/sys/fs/binfmt_misc/status` before testing.

builders/darwin.aarch64/Dockerfile

@@ -0,0 +1,40 @@
+FROM ghcr.io/shepherdjerred/macos-cross-compiler@sha256:7d40c5e179d5d15453cf2a6b1bba3392bb1448b8257ee6b86021fc905c59dad6
+
+ENV TARGET=aarch64-apple-darwin22
+ENV TARGETNAME=darwin.aarch64
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND=noninteractive
+ENV LC_ALL=C.utf8
+
+# Install basic deps
+RUN apt-get update && apt-get install -y automake autoconf build-essential curl xz-utils qemu-user-static
+
+# Install a more suitable host compiler
+WORKDIR /host-ghc
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.9.0.0/cabal-install-3.9-x86_64-linux-alpine.tar.xz" | tar xJv -C /usr/local/bin
+RUN curl -L 'https://downloads.haskell.org/~ghc/8.10.7/ghc-8.10.7-x86_64-deb10-linux.tar.xz' | tar xJ --strip-components=1
+RUN ./configure && make install
+
+# Build GHC. We have to use an old version because cross-compilation across OS has since broken.
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/8.10.7/ghc-8.10.7-src.tar.xz" | tar xJ --strip-components=1
+RUN apt-get install -y llvm-12
+RUN ./boot && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
+RUN make install
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS="--ghc-options;-optc-Os -optc-fPIC;--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg;--constraint=hashable==1.3.5.0"
+
+# Prebuild the dependencies
+RUN cabal update
+RUN IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

builders/darwin.aarch64/build

@@ -0,0 +1,16 @@
+#!/bin/sh
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  ( IFS=';'; cabal build $CABALOPTS )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  # Stripping invalidates the code signature and the build image does
+  # not appear to have anything similar to the 'codesign' tool.
+  # "$TARGET-strip" "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  file "$TARGETNAME/shellcheck" | grep "Mach-O 64-bit arm64 executable"
+} >&2
+tar czv "$TARGETNAME"

builders/darwin.aarch64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-darwin-aarch64

builders/darwin.x86_64/Dockerfile

@@ -0,0 +1,33 @@
+FROM liushuyu/osxcross@sha256:fa32af4677e2860a1c5950bc8c360f309e2a87e2ddfed27b642fddf7a6093b76
+
+ENV TARGET=x86_64-apple-darwin18
+ENV TARGETNAME=darwin.x86_64
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND=noninteractive
+RUN sed -e 's/focal/kinetic/g' -e 's/archive\|security/old-releases/' -i /etc/apt/sources.list
+RUN apt-get update
+RUN apt-get dist-upgrade -y
+RUN apt-get install -y ghc automake autoconf llvm curl alex happy
+
+# Build GHC
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/9.2.8/ghc-9.2.8-src.tar.xz" | tar xJ --strip-components=1
+RUN ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+RUN cp mk/flavours/quick-cross.mk mk/build.mk && make -j "$(nproc)"
+RUN make install
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.9.0.0/cabal-install-3.9-x86_64-linux-alpine.tar.xz" | tar xJv -C /usr/local/bin
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS="--with-ghc=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg"
+
+# Prebuild the dependencies
+RUN cabal update && IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

builders/darwin.x86_64/build

@@ -2,9 +2,8 @@
 set -xe
 {
   tar xzv --strip-components=1
-  ./striptests
+  chmod +x striptests && ./striptests
   mkdir "$TARGETNAME"
-  cabal update
   ( IFS=';'; cabal build $CABALOPTS )
   find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
   ls -l "$TARGETNAME"

builders/linux.aarch64/Dockerfile

@@ -0,0 +1,35 @@
+FROM ubuntu:25.04
+
+ENV TARGET=aarch64-linux-gnu
+ENV TARGETNAME=linux.aarch64
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update && apt-get install -y llvm-20 "gcc-$TARGET" "g++-$TARGET" ghc alex happy automake autoconf build-essential curl qemu-user-static
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.16.0.0/cabal-install-3.16.0.0-x86_64-linux-alpine3_20.tar.xz" | tar xJv -C /usr/local/bin && cabal update
+
+# Build GHC
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/9.12.2/ghc-9.12.2-src.tar.xz" | tar xJ --strip-components=1
+RUN ./boot.source && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+# GHC fails to build if it can't encode non-ascii
+ENV LC_CTYPE=C.utf8
+# We have to do a binary-dist instead of a direct install, otherwise the targest won't have
+# cross compilation prefixes in /usr/local/lib/aarch64-linux-gnu-ghc-*/lib/settings
+RUN ./hadrian/build --flavour=quickest --bignum=native -V -j --prefix=/usr/local install
+# Hadrian just outputs "gcc" as the name of gcc, without accounting for $TARGET. Manually fix up the paths:
+RUN sed -e 's/"\(gcc\|g++\|ld\)"/"'"$TARGET"'-\1"/g' -i /usr/local/lib/$TARGET-ghc-*/lib/settings
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS="--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections -optc-fPIC;--with-compiler=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg;-c;hashable -arch-native"
+
+# Prebuild the dependencies
+RUN cabal update && IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

builders/linux.aarch64/build

@@ -2,14 +2,13 @@
 set -xe
 {
   tar xzv --strip-components=1
-  ./striptests
+  chmod +x striptests && ./striptests
   mkdir "$TARGETNAME"
-  cabal update
   ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )
   find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
   ls -l "$TARGETNAME"
   "$TARGET-strip" -s "$TARGETNAME/shellcheck"
   ls -l "$TARGETNAME"
-  qemu-aarch64-static "$TARGETNAME/shellcheck" --version
+  "qemu-${TARGET%%-*}-static" "$TARGETNAME/shellcheck" --version
 } >&2
 tar czv "$TARGETNAME"

builders/linux.armv6hf/Dockerfile

@@ -0,0 +1,42 @@
+# This Docker file uses a custom QEmu fork with patches to follow execve
+# to build all of ShellCheck emulated.
+
+FROM ubuntu:25.04
+
+ENV TARGETNAME linux.armv6hf
+
+# Build QEmu with execve follow support
+USER root
+ENV DEBIAN_FRONTEND noninteractive
+RUN apt-get update
+RUN apt-get install -y --no-install-recommends build-essential git ninja-build python3 pkg-config libglib2.0-dev libpixman-1-dev python3-setuptools ca-certificates debootstrap
+WORKDIR /qemu
+RUN git clone --depth 1 https://github.com/koalaman/qemu .
+RUN ./configure --static --disable-werror && cd build && ninja qemu-arm
+ENV QEMU_EXECVE 1
+
+# Convenience utility
+COPY scutil /bin/scutil
+COPY scutil /chroot/bin/scutil
+RUN chmod +x /bin/scutil /chroot/bin/scutil
+
+# Set up an armv6 userspace
+WORKDIR /
+RUN debootstrap --arch armhf --variant=minbase --foreign bookworm /chroot http://mirrordirector.raspbian.org/raspbian
+RUN cp /qemu/build/qemu-arm /chroot/bin/qemu
+RUN scutil emu /debootstrap/debootstrap --second-stage
+
+# Install deps in the chroot
+RUN scutil emu apt-get update
+RUN scutil emu apt-get install -y --no-install-recommends ghc cabal-install
+RUN scutil emu cabal update
+
+# Finally we can build the current dependencies. This takes hours.
+ENV CABALOPTS "--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections;--gcc-options;-Os -Wl,--gc-sections -ffunction-sections -fdata-sections"
+# Generated with `cabal freeze --constraint 'hashable -arch-native'`
+COPY cabal.project.freeze /chroot/etc
+RUN IFS=";" && scutil install_from_freeze /chroot/etc/cabal.project.freeze emu cabal install $CABALOPTS
+
+# Copy the build script
+COPY build /chroot/bin
+ENTRYPOINT ["/bin/scutil", "emu", "/bin/build"]

builders/linux.armv6hf/build

@@ -1,9 +1,10 @@
 #!/bin/sh
 set -xe
-cd /scratch
+mkdir /scratch && cd /scratch
 {
   tar xzv --strip-components=1
-  ./striptests
+  cp /etc/cabal.project.freeze .
+  chmod +x striptests && ./striptests
   mkdir "$TARGETNAME"
   # This script does not cabal update because compiling anything new is slow
   ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )

builders/linux.armv6hf/cabal.project.freeze

@@ -0,0 +1,105 @@
+active-repositories: hackage.haskell.org:merge
+constraints: any.Diff ==1.0.2,
+             any.OneTuple ==0.4.2,
+             any.QuickCheck ==2.16.0.0,
+             QuickCheck -old-random +templatehaskell,
+             any.StateVar ==1.2.2,
+             any.aeson ==2.2.3.0,
+             aeson +ordered-keymap,
+             any.ansi-terminal ==1.1.3,
+             ansi-terminal -example,
+             any.ansi-terminal-types ==1.1.3,
+             any.array ==0.5.4.0,
+             any.assoc ==1.1.1,
+             assoc -tagged,
+             any.base ==4.15.1.0,
+             any.base-orphans ==0.9.3,
+             any.bifunctors ==5.6.2,
+             bifunctors +tagged,
+             any.binary ==0.8.8.0,
+             any.bytestring ==0.10.12.1,
+             any.character-ps ==0.1,
+             any.colour ==2.3.6,
+             any.comonad ==5.0.9,
+             comonad +containers +distributive +indexed-traversable,
+             any.containers ==0.6.4.1,
+             any.contravariant ==1.5.5,
+             contravariant +semigroups +statevar +tagged,
+             any.data-array-byte ==0.1.0.1,
+             any.data-fix ==0.3.4,
+             any.deepseq ==1.4.5.0,
+             any.directory ==1.3.6.2,
+             any.distributive ==0.6.2.1,
+             distributive +semigroups +tagged,
+             any.dlist ==1.0,
+             dlist -werror,
+             any.exceptions ==0.10.4,
+             any.fgl ==5.8.3.0,
+             fgl +containers042,
+             any.filepath ==1.4.2.1,
+             any.foldable1-classes-compat ==0.1.2,
+             foldable1-classes-compat +tagged,
+             any.generically ==0.1.1,
+             any.ghc-bignum ==1.1,
+             any.ghc-boot-th ==9.0.2,
+             any.ghc-prim ==0.7.0,
+             any.hashable ==1.4.7.0,
+             hashable -arch-native +integer-gmp -random-initial-seed,
+             any.indexed-traversable ==0.1.4,
+             any.indexed-traversable-instances ==0.1.2,
+             any.integer-conversion ==0.1.1,
+             any.integer-logarithms ==1.0.4,
+             integer-logarithms -check-bounds +integer-gmp,
+             any.mtl ==2.2.2,
+             any.network-uri ==2.6.4.2,
+             any.optparse-applicative ==0.19.0.0,
+             optparse-applicative +process,
+             any.parsec ==3.1.14.0,
+             any.pretty ==1.1.3.6,
+             any.prettyprinter ==1.7.1,
+             prettyprinter -buildreadme +text,
+             any.prettyprinter-ansi-terminal ==1.1.3,
+             any.primitive ==0.9.1.0,
+             any.process ==1.6.13.2,
+             any.random ==1.3.1,
+             any.regex-base ==0.94.0.3,
+             any.regex-tdfa ==1.3.2.4,
+             regex-tdfa +doctest -force-o2,
+             any.rts ==1.0.2,
+             any.scientific ==0.3.8.0,
+             scientific -integer-simple,
+             any.semialign ==1.3.1,
+             semialign +semigroupoids,
+             any.semigroupoids ==6.0.1,
+             semigroupoids +comonad +containers +contravariant +distributive +tagged +unordered-containers,
+             any.splitmix ==0.1.3.1,
+             splitmix -optimised-mixer,
+             any.stm ==2.5.0.0,
+             any.strict ==0.5.1,
+             any.tagged ==0.8.9,
+             tagged +deepseq +transformers,
+             any.tasty ==1.5.3,
+             tasty +unix,
+             any.template-haskell ==2.17.0.0,
+             any.text ==1.2.5.0,
+             any.text-iso8601 ==0.1.1,
+             any.text-short ==0.1.6,
+             text-short -asserts,
+             any.th-abstraction ==0.7.1.0,
+             any.th-compat ==0.1.6,
+             any.these ==1.2.1,
+             any.time ==1.9.3,
+             any.time-compat ==1.9.8,
+             any.transformers ==0.5.6.2,
+             any.transformers-compat ==0.7.2,
+             transformers-compat -five +five-three -four +generic-deriving +mtl -three -two,
+             any.unbounded-delays ==0.1.1.1,
+             any.unix ==2.7.2.2,
+             any.unordered-containers ==0.2.20,
+             unordered-containers -debug,
+             any.uuid-types ==1.0.6,
+             any.vector ==0.13.2.0,
+             vector +boundschecks -internalchecks -unsafechecks -wall,
+             any.vector-stream ==0.1.0.1,
+             any.witherable ==0.5
+index-state: hackage.haskell.org 2025-07-22T18:12:16Z

builders/linux.armv6hf/scutil

@@ -0,0 +1,48 @@
+#!/bin/dash
+# Various ShellCheck build utility functions
+
+# Generally set a ulimit to avoid QEmu using too much memory
+ulimit -v "$((10*1024*1024))"
+# If we happen to invoke or run under QEmu, make sure to follow execve.
+# This requires a patched QEmu.
+export QEMU_EXECVE=1
+
+# Retry a command until it succeeds
+# Usage: scutil retry 3 mycmd
+retry() {
+  n="$1"
+  ret=1
+  shift
+  while [ "$n" -gt 0 ]
+  do
+    "$@"
+    ret=$?
+    [ "$ret" = 0 ] && break
+    n=$((n-1))
+  done
+  return "$ret"
+}
+
+# Install all dependencies from a freeze file
+# Usage: scutil install_from_freeze /path/cabal.project.freeze cabal install
+install_from_freeze() {
+  linefeed=$(printf '\nx')
+  linefeed=${linefeed%x}
+  flags=$(
+    sed 's/constraints:/&\n /' "$1" |
+    grep -vw -e rts -e base -e ghc |
+    sed -n -e 's/^  *\([^,]*\).*/\1/p' |
+    sed -e 's/any\.\([^ ]*\) ==\(.*\)/\1-\2/; te; s/.*/--constraint\n&/; :e')
+  shift
+  # shellcheck disable=SC2086
+  ( IFS=$linefeed; set -x; "$@" $flags )
+}
+
+# Run a command under emulation.
+# This assumes the correct emulator is named 'qemu' and the chroot is /chroot
+# Usage: scutil emu echo "Hello World"
+emu() {
+  chroot /chroot /bin/qemu /usr/bin/env "$@"
+}
+
+"$@"

builders/linux.riscv64/Dockerfile

@@ -0,0 +1,35 @@
+FROM ubuntu:25.04
+
+ENV TARGETNAME=linux.riscv64
+ENV TARGET=riscv64-linux-gnu
+
+# Build dependencies
+USER root
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update && apt-get install -y llvm-20 "gcc-$TARGET" "g++-$TARGET" ghc alex happy automake autoconf build-essential curl qemu-user-static
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.16.0.0/cabal-install-3.16.0.0-x86_64-linux-alpine3_20.tar.xz" | tar xJv -C /usr/local/bin && cabal update
+
+# Build GHC
+WORKDIR /ghc
+RUN curl -L "https://downloads.haskell.org/~ghc/9.12.2/ghc-9.12.2-src.tar.xz" | tar xJ --strip-components=1
+RUN ./boot.source && ./configure --host x86_64-linux-gnu --build x86_64-linux-gnu --target "$TARGET"
+# GHC fails to build if it can't encode non-ascii
+ENV LC_CTYPE=C.utf8
+# We have to do a binary-dist instead of a direct install, otherwise the targest won't have
+# cross compilation prefixes in /usr/local/lib/aarch64-linux-gnu-ghc-*/lib/settings
+RUN ./hadrian/build --flavour=quickest --bignum=native -V -j --prefix=/usr/local install
+# Hadrian just outputs "gcc" as the name of gcc, without accounting for $TARGET. Manually fix up the paths:
+RUN sed -e 's/"\(gcc\|g++\|ld\)"/"'"$TARGET"'-\1"/g' -i /usr/local/lib/$TARGET-ghc-*/lib/settings
+
+# Due to an apparent cabal bug, we specify our options directly to cabal
+# It won't reuse caches if ghc-options are specified in ~/.cabal/config
+ENV CABALOPTS="--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections -optc-fPIC;--with-compiler=$TARGET-ghc;--with-hc-pkg=$TARGET-ghc-pkg;-c;hashable -arch-native"
+
+# Prebuild the dependencies
+RUN cabal update && IFS=';' && cabal install --dependencies-only $CABALOPTS ShellCheck
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

builders/linux.riscv64/build

@@ -0,0 +1,14 @@
+#!/bin/sh
+set -xe
+{
+  tar xzv --strip-components=1
+  chmod +x striptests && ./striptests
+  mkdir "$TARGETNAME"
+  ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )
+  find . -name shellcheck -type f -exec mv {} "$TARGETNAME/" \;
+  ls -l "$TARGETNAME"
+  "$TARGET-strip" -s "$TARGETNAME/shellcheck"
+  ls -l "$TARGETNAME"
+  "qemu-${TARGET%%-*}-static" "$TARGETNAME/shellcheck" --version
+} >&2
+tar czv "$TARGETNAME"

builders/linux.riscv64/tag

@@ -0,0 +1 @@
+koalaman/scbuilder-linux-riscv64

builders/linux.x86_64/Dockerfile

@@ -0,0 +1,30 @@
+FROM alpine:3.22
+# alpine:3.16 (GHC 9.0.1):  5.8 megabytes (certs expired)
+# alpine:3.17 (GHC 9.0.2): 15.0 megabytes (certs expired)
+# alpine:3.18 (GHC 9.4.4): 29.0 megabytes (certs expired)
+# alpine:3.19 (GHC 9.4.7): 29.0 megabytes (certs expired)
+# alpine:3.20 (GHC 9.8.2): 16.0 megabytes
+# alpine:3.21 (GHC 9.8.2): 16.0 megabytes
+# alpine:3.22 (GHC 9.8.2): 16.0 megabytes
+
+ENV TARGETNAME=linux.x86_64
+
+# Install GHC and cabal
+USER root
+RUN apk add ghc cabal g++ libffi-dev curl bash gmp gmp-static
+
+# Cabal has failed to cache if options are not specified on the command line,
+# so do that explicitly.
+ENV CABALOPTS="--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections"
+
+# Verify that we have the certificates in place to successfully update cabal
+RUN cabal update && rm -rf ~/.cabal
+
+# Other archs pre-build dependencies here, but this one doesn't to detect ecosystem movement
+RUN true
+
+# Copy the build script
+COPY build /usr/bin
+
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

builders/linux.x86_64/build

@@ -2,7 +2,7 @@
 set -xe
 {
   tar xzv --strip-components=1
-  ./striptests
+  chmod +x striptests && ./striptests
   mkdir "$TARGETNAME"
   cabal update
   ( IFS=';'; cabal build $CABALOPTS --enable-executable-static )

builders/windows.x86_64/Dockerfile

@@ -0,0 +1,34 @@
+FROM ubuntu:25.04
+
+ENV TARGETNAME=windows.x86_64
+
+# We don't need wine32, even though it complains
+USER root
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update && apt-get install -y curl busybox wine winbind xz-utils
+
+# Fetch Windows version, will be available under z:\haskell
+WORKDIR /haskell
+# 9.12.2 produces a 37M binary
+# 9.0.2  produces a 28M binary
+# 8.10.4 produces a 16M binary
+# We don't want to be stuck on old versions forever though, so just go with the latest version
+RUN curl -L "https://downloads.haskell.org/~ghc/9.12.2/ghc-9.12.2-x86_64-unknown-mingw32.tar.xz" | tar xJ --strip-components=1
+
+# Fetch dependencies
+WORKDIR /haskell/bin
+RUN curl -L "https://downloads.haskell.org/~cabal/cabal-install-3.16.0.0/cabal-install-3.16.0.0-x86_64-windows.zip" | busybox unzip -
+RUN curl -L "https://curl.se/windows/dl-8.15.0_2/curl-8.15.0_2-win64-mingw.zip" | busybox unzip - && mv curl-*-win64-mingw/bin/* .
+RUN wine /haskell/bin/cabal.exe update
+ENV WINEPATH=/haskell/bin:/haskell/mingw/bin
+
+# None of these actually seem to have an effect on GHC on Windows anymore,
+# but we'll leave them in place anyways.
+ENV CABALOPTS="--ghc-options;-split-sections -optc-Os -optc-Wl,--gc-sections"
+
+# Precompile some deps to speed up later builds
+RUN IFS=';' && wine /haskell/bin/cabal.exe install --lib --dependencies-only $CABALOPTS ShellCheck
+
+COPY build /usr/bin
+WORKDIR /scratch
+ENTRYPOINT ["/usr/bin/build"]

builders/windows.x86_64/build

@@ -6,9 +6,8 @@ cabal() {
 set -xe
 {
   tar xzv --strip-components=1
-  ./striptests
+  chmod +x striptests && ./striptests
   mkdir "$TARGETNAME"
-  cabal update
   ( IFS=';'; cabal build $CABALOPTS )
   find dist*/ -name shellcheck.exe -type f -ls -exec mv {} "$TARGETNAME/" \;
   ls -l "$TARGETNAME"

quickrun

@@ -2,4 +2,12 @@
 # quickrun runs ShellCheck in an interpreted mode.
 # This allows testing changes without recompiling.
 
-runghc -isrc -idist/build/autogen shellcheck.hs "$@"
+path=$(find . -type f -path './dist*/Paths_ShellCheck.hs' | sort | head -n 1)
+if [ -z "$path" ]
+then
+  echo >&2 "Unable to find Paths_ShellCheck.hs. Please 'cabal build' once."
+  exit 1
+fi
+path="${path%/*}"
+
+exec runghc -isrc -i"$path" shellcheck.hs "$@"

quicktest

@@ -3,8 +3,17 @@
 # This allows running tests without compiling, which can be faster.
 # 'cabal test' remains the source of truth.
 
+path=$(find . -type f -path './dist*/Paths_ShellCheck.hs' | sort | head -n 1)
+if [ -z "$path" ]
+then
+    echo >&2 "Unable to find Paths_ShellCheck.hs. Please 'cabal build' once."
+      exit 1
+fi
+path="${path%/*}"
+
+
 (
-var=$(echo 'main' | ghci test/shellcheck.hs 2>&1 | tee /dev/stderr)
+var=$(echo 'main' | ghci -isrc -i"$path" test/shellcheck.hs 2>&1 | tee /dev/stderr)
 if [[ $var == *ExitSuccess* ]]
 then
   exit 0

setgitversion

@@ -0,0 +1,11 @@
+#!/bin/sh -xe
+# This script hardcodes the `git describe` version as ShellCheck's version number.
+# This is done to allow shellcheck --version to differ from the cabal version when
+# building git snapshots.
+
+file="src/ShellCheck/Data.hs"
+test -e "$file"
+tmp=$(mktemp)
+version=$(git describe)
+sed -e "s/=.*VERSIONSTRING.*/= \"$version\" -- VERSIONSTRING, DO NOT SUBMIT/" "$file" > "$tmp"
+mv "$tmp" "$file"

shellcheck.1.md

@@ -56,6 +56,13 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
     options are cumulative, but all the codes can be specified at once,
     comma-separated as a single argument.
 
+**--extended-analysis=true/false**
+
+:   Enable/disable Dataflow Analysis to identify more issues (default true). If
+    ShellCheck uses too much CPU/RAM when checking scripts with several
+    thousand lines of code, extended analysis can be disabled with this flag
+    or a directive. This flag overrides directives and rc files.
+
 **-f** *FORMAT*, **--format=***FORMAT*
 
 :   Specify the output format of shellcheck, which prints its results in the
@@ -71,6 +78,11 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
 
 :   Don't try to look for .shellcheckrc configuration files.
 
+**--rcfile** *RCFILE*
+
+:   Prefer the specified configuration file over searching for one
+    in the default locations.
+
 **-o**\ *NAME1*[,*NAME2*...],\ **--enable=***NAME1*[,*NAME2*...]
 
 :   Enable optional checks. The special name *all* enables all of them.
@@ -85,7 +97,8 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
 
 **-s**\ *shell*,\ **--shell=***shell*
 
-:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *dash* and *ksh*.
+:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *dash*, *ksh*,
+    and *busybox*.
     The default is to deduce the shell from the file's `shell` directive,
     shebang, or `.bash/.bats/.dash/.ksh` extension, in that order. *sh* refers to
     POSIX `sh` (not the system's), and will warn of portability issues.
@@ -112,6 +125,9 @@ not warn at all, as `ksh` supports decimals in arithmetic contexts.
     line (plus `/dev/null`). This option allows following any file the script
     may `source`.
 
+    This option may also be enabled using `external-sources=true` in
+    `.shellcheckrc`. This flag takes precedence.
+
 **FILES...**
 
 :   One or more script files to check, or "-" for standard input.
@@ -234,11 +250,26 @@ Valid keys are:
     The command can be a simple command like `echo foo`, or a compound command
     like a function definition, subshell block or loop. A range can be
     be specified with a dash, e.g. `disable=SC3000-SC4000` to exclude 3xxx.
+    All warnings can be disabled with `disable=all`.
 
 **enable**
 :   Enable an optional check by name, as listed with **--list-optional**.
     Only file-wide `enable` directives are considered.
 
+**extended-analysis**
+:   Set to true/false to enable/disable dataflow analysis. Specifying
+    `# shellcheck extended-analysis=false` in particularly large (2000+ line)
+    auto-generated scripts will reduce ShellCheck's resource usage at the
+    expense of certain checks. Extended analysis is enabled by default.
+
+**external-sources**
+:   Set to `true` in `.shellcheckrc` to always allow ShellCheck to open
+    arbitrary files from 'source' statements (the way most tools do).
+
+    This option defaults to `false` only due to ShellCheck's origin as a
+    remote service for checking untrusted scripts. It can safely be enabled
+    for normal development.
+
 **source**
 :   Overrides the filename included by a `source`/`.` statement. This can be
     used to tell shellcheck where to look for a file whose name is determined
@@ -270,6 +301,12 @@ Here is an example `.shellcheckrc`:
     source-path=SCRIPTDIR
     source-path=/mnt/chroot
 
+    # Since 0.9.0, values can be quoted with '' or "" to allow spaces
+    source-path="My Documents/scripts"
+
+    # Allow opening any 'source'd file, even if not specified as input
+    external-sources=true
+
     # Turn on warnings for unquoted variables with safe values
     enable=quote-safe-variables
 
@@ -280,7 +317,7 @@ Here is an example `.shellcheckrc`:
     disable=SC2236
 
 If no `.shellcheckrc` is found in any of the parent directories, ShellCheck
-will look in `~/.shellcheckrc` followed by the XDG config directory
+will look in `~/.shellcheckrc` followed by the `$XDG_CONFIG_HOME`
 (usually `~/.config/shellcheckrc`) on Unix, or `%APPDATA%/shellcheckrc` on
 Windows. Only the first file found will be used.
 
@@ -320,10 +357,32 @@ locales where encoding is unspecified (such as the `C` locale).
 Windows users seeing `commitBuffer: invalid argument (invalid character)`
 should set their terminal to use UTF-8 with `chcp 65001`.
 
-# AUTHORS
+# KNOWN INCOMPATIBILITIES
 
-ShellCheck is developed and maintained by Vidar Holen, with assistance from a
+(If nothing in this section makes sense, you are unlikely to be affected by it)
-long list of wonderful contributors.
+
+To avoid confusing and misguided suggestions, ShellCheck requires function
+bodies to be either `{ brace groups; }` or `( subshells )`, and function names
+containing `[]*=!` are only recognized after a `function` keyword.
+
+The following unconventional function definitions are identical in Bash,
+but ShellCheck only recognizes the latter.
+
+    [x!=y] () [[ $1 ]]
+    function [x!=y] () { [[ $1 ]]; }
+
+Shells without the `function` keyword do not allow these characters in function
+names to begin with.  Function names containing `{}` are not supported at all.
+
+Further, if ShellCheck sees `[x!=y]` it will assume this is an invalid
+comparison. To invoke the above function, quote the command as in `'[x!=y]'`,
+or to retain the same globbing behavior, use `command [x!=y]`.
+
+ShellCheck imposes additional restrictions on the `[` command to help diagnose
+common invalid uses. While `[ $x= 1 ]` is defined in POSIX, ShellCheck will
+assume it was intended as the much more likely comparison `[ "$x" = 1 ]` and
+fail accordingly. For unconventional or dynamic uses of the `[` command, use
+`test` or `\[` instead.
 
 # REPORTING BUGS
 
@@ -331,12 +390,17 @@ Bugs and issues can be reported on GitHub:
 
 https://github.com/koalaman/shellcheck/issues
 
+# AUTHORS
+
+ShellCheck is developed and maintained by Vidar Holen, with assistance from a
+long list of wonderful contributors.
+
 # COPYRIGHT
 
-Copyright 2012-2019, Vidar Holen and contributors.
+Copyright 2012-2025, Vidar Holen and contributors.
 Licensed under the GNU General Public License version 3 or later,
 see https://gnu.org/licenses/gpl.html
 
 # SEE ALSO
 
-sh(1) bash(1)
+sh(1), bash(1), dash(1), ksh(1)

shellcheck.hs

@@ -34,6 +34,8 @@ import qualified ShellCheck.Formatter.Quiet
 
 import           Control.Exception
 import           Control.Monad
+import           Control.Monad.IO.Class
+import           Control.Monad.Trans.Class
 import           Control.Monad.Except
 import           Data.Bits
 import           Data.Char
@@ -74,7 +76,8 @@ data Options = Options {
     externalSources  :: Bool,
     sourcePaths      :: [FilePath],
     formatterOptions :: FormatterOptions,
-    minSeverity      :: Severity
+    minSeverity      :: Severity,
+    rcfile           :: Maybe FilePath
 }
 
 defaultOptions = Options {
@@ -84,7 +87,8 @@ defaultOptions = Options {
     formatterOptions = newFormatterOptions {
         foColorOption = ColorAuto
     },
-    minSeverity = StyleC
+    minSeverity = StyleC,
+    rcfile = Nothing
 }
 
 usageHeader = "Usage: shellcheck [OPTIONS...] FILES..."
@@ -98,6 +102,8 @@ options = [
         (ReqArg (Flag "include") "CODE1,CODE2..") "Consider only given types of warnings",
     Option "e" ["exclude"]
         (ReqArg (Flag "exclude") "CODE1,CODE2..") "Exclude types of warnings",
+    Option "" ["extended-analysis"]
+        (ReqArg (Flag "extended-analysis") "bool") "Perform dataflow analysis (default true)",
     Option "f" ["format"]
         (ReqArg (Flag "format") "FORMAT") $
         "Output format (" ++ formatList ++ ")",
@@ -105,6 +111,9 @@ options = [
         (NoArg $ Flag "list-optional" "true") "List checks disabled by default",
     Option "" ["norc"]
         (NoArg $ Flag "norc" "true") "Don't look for .shellcheckrc files",
+    Option "" ["rcfile"]
+        (ReqArg (Flag "rcfile") "RCFILE")
+        "Prefer the specified configuration file over searching for one",
     Option "o" ["enable"]
         (ReqArg (Flag "enable") "check1,check2..")
         "List of optional checks to enable (or 'all')",
@@ -113,7 +122,7 @@ options = [
         "Specify path when looking for sourced files (\"SCRIPTDIR\" for script's dir)",
     Option "s" ["shell"]
         (ReqArg (Flag "shell") "SHELLNAME")
-        "Specify dialect (sh, bash, dash, ksh)",
+        "Specify dialect (sh, bash, dash, ksh, busybox)",
     Option "S" ["severity"]
         (ReqArg (Flag "severity") "SEVERITY")
         "Minimum severity of errors to consider (error, warning, info, style)",
@@ -225,7 +234,7 @@ runFormatter sys format options files = do
     f :: Status -> FilePath -> IO Status
     f status file = do
         newStatus <- process file `catch` handler file
-        return $ status `mappend` newStatus
+        return $! status `mappend` newStatus
     handler :: FilePath -> IOException -> IO Status
     handler file e = reportFailure file (show e)
     reportFailure file str = do
@@ -234,7 +243,7 @@ runFormatter sys format options files = do
 
     process :: FilePath -> IO Status
     process filename = do
-        input <- siReadFile sys filename
+        input <- siReadFile sys Nothing filename
         either (reportFailure filename) check input
       where
         check contents = do
@@ -250,9 +259,9 @@ runFormatter sys format options files = do
                 else SomeProblems
 
 parseEnum name value list =
-    case filter ((== value) . fst) list of
+    case lookup value list of
-        [(name, value)] -> return value
+        Just value -> return value
-        [] -> do
+        Nothing -> do
             printErr $ "Unknown value for --" ++ name ++ ". " ++
                        "Valid options are: " ++ (intercalate ", " $ map fst list)
             throwError SupportFailure
@@ -365,6 +374,11 @@ parseOption flag options =
                 }
             }
 
+        Flag "rcfile" str -> do
+            return options {
+                rcfile = Just str
+            }
+
         Flag "enable" value ->
             let cs = checkSpec options in return options {
                 checkSpec = cs {
@@ -372,6 +386,14 @@ parseOption flag options =
                 }
             }
 
+        Flag "extended-analysis" str -> do
+            value <- parseBool str
+            return options {
+                checkSpec = (checkSpec options) {
+                    csExtendedAnalysis = Just value
+                }
+            }
+
         -- This flag is handled specially in 'process'
         Flag "format" _ -> return options
 
@@ -389,11 +411,20 @@ parseOption flag options =
             throwError SyntaxFailure
         return (Prelude.read num :: Integer)
 
+    parseBool str = do
+        case str of
+            "true" -> return True
+            "false" -> return False
+            _ -> do
+                printErr $ "Invalid boolean, expected true/false: " ++ str
+                throwError SyntaxFailure
+
+ioInterface :: Options -> [FilePath] -> IO (SystemInterface IO)
 ioInterface options files = do
     inputs <- mapM normalize files
     cache <- newIORef emptyCache
     configCache <- newIORef ("", Nothing)
-    return SystemInterface {
+    return (newSystemInterface :: SystemInterface IO) {
         siReadFile = get cache inputs,
         siFindSource = findSourceFile inputs (sourcePaths options),
         siGetConfig = getConfig configCache
@@ -402,14 +433,14 @@ ioInterface options files = do
     emptyCache :: Map.Map FilePath String
     emptyCache = Map.empty
 
-    get cache inputs file = do
+    get cache inputs rcSuggestsExternal file = do
         map <- readIORef cache
         case Map.lookup file map of
             Just x  -> return $ Right x
-            Nothing -> fetch cache inputs file
+            Nothing -> fetch cache inputs rcSuggestsExternal file
 
-    fetch cache inputs file = do
+    fetch cache inputs rcSuggestsExternal file = do
-        ok <- allowable inputs file
+        ok <- allowable rcSuggestsExternal inputs file
         if ok
           then (do
             (contents, shouldCache) <- inputFile file
@@ -417,13 +448,16 @@ ioInterface options files = do
                 modifyIORef cache $ Map.insert file contents
             return $ Right contents
             ) `catch` handler
-          else return $ Left (file ++ " was not specified as input (see shellcheck -x).")
+          else
+            if rcSuggestsExternal == Just False
+            then return $ Left (file ++ " was not specified as input, and external files were disabled via directive.")
+            else return $ Left (file ++ " was not specified as input (see shellcheck -x).")
       where
         handler :: IOException -> IO (Either ErrorMessage String)
         handler ex = return . Left $ show ex
 
-    allowable inputs x =
+    allowable rcSuggestsExternal inputs x =
-        if externalSources options
+        if fromMaybe (externalSources options) rcSuggestsExternal
         then return True
         else do
             path <- normalize x
@@ -435,18 +469,33 @@ ioInterface options files = do
         fallback :: FilePath -> IOException -> IO FilePath
         fallback path _ = return path
 
+
     -- Returns the name and contents of .shellcheckrc for the given file
-    getConfig cache filename = do
+    getConfig cache filename =
-        path <- normalize filename
+        case rcfile options of
-        let dir = takeDirectory path
+            Just file -> do
-        (previousPath, result) <- readIORef cache
+                -- We have a specified rcfile. Ignore normal rcfile resolution.
-        if dir == previousPath
+                (path, result) <- readIORef cache
-          then return result
+                if path == "/"
-          else do
+                  then return result
-            paths <- getConfigPaths dir
+                  else do
-            result <- findConfig paths
+                    result <- readConfig file
-            writeIORef cache (dir, result)
+                    when (isNothing result) $
-            return result
+                        hPutStrLn stderr $ "Warning: unable to read --rcfile " ++ file
+                    writeIORef cache ("/", result)
+                    return result
+
+            Nothing -> do
+                path <- normalize filename
+                let dir = takeDirectory path
+                (previousPath, result) <- readIORef cache
+                if dir == previousPath
+                  then return result
+                  else do
+                    paths <- getConfigPaths dir
+                    result <- findConfig paths
+                    writeIORef cache (dir, result)
+                    return result
 
     findConfig paths =
         case paths of
@@ -484,7 +533,7 @@ ioInterface options files = do
       where
         handler :: FilePath -> IOException -> IO (String, Bool)
         handler file err = do
-            putStrLn $ file ++ ": " ++ show err
+            hPutStrLn stderr $ file ++ ": " ++ show err
             return ("", True)
 
     andM a b arg = do
@@ -497,7 +546,7 @@ ioInterface options files = do
             b <- p x
             if b then pure (Just x) else acc
 
-    findSourceFile inputs sourcePathFlag currentScript sourcePathAnnotation original =
+    findSourceFile inputs sourcePathFlag currentScript rcSuggestsExternal sourcePathAnnotation original =
         if isAbsolute original
         then
             let (_, relative) = splitDrive original
@@ -506,7 +555,7 @@ ioInterface options files = do
             find original original
       where
         find filename deflt = do
-            sources <- findM ((allowable inputs) `andM` doesFileExist) $
+            sources <- findM ((allowable rcSuggestsExternal inputs) `andM` doesFileExist) $
                         (adjustPath filename):(map ((</> filename) . adjustPath) $ sourcePathFlag ++ sourcePathAnnotation)
             case sources of
                 Nothing -> return deflt

snap/snapcraft.yaml

@@ -23,7 +23,7 @@ description: |
       # snap connect shellcheck:removable-media
 
 version: git
-base: core18
+base: core24
 grade: stable
 confinement: strict
 
@@ -40,17 +40,18 @@ parts:
     source: .
     build-packages:
       - cabal-install
-      - squid
     override-build: |
-      # See comments in .snapsquid.conf
+      # Give ourselves enough memory to build
-      [ "$http_proxy" ] && {
+      fallocate -l 2G /tmp/swap
-        squid3 -f .snapsquid.conf
+      chmod 0600 /tmp/swap
-        export http_proxy="http://localhost:8888"
+      mkswap /tmp/swap
-        sleep 3
+      if ! swapon /tmp/swap; then
-      }
+        echo "Could not enable swap file, continuing anyway"
-      cabal sandbox init
+        rm /tmp/swap
-      cabal update || cat /var/log/squid/*
+      fi
+
+      cabal update
       cabal install -j
 
-      install -d $SNAPCRAFT_PART_INSTALL/usr/bin
+      install -d "${CRAFT_PART_INSTALL}/usr/bin"
-      install .cabal-sandbox/bin/shellcheck $SNAPCRAFT_PART_INSTALL/usr/bin
+      install --strip ~/.cabal/bin/shellcheck "${CRAFT_PART_INSTALL}/usr/bin"

src/ShellCheck/AST.hs

@@ -31,6 +31,7 @@ newtype Id = Id Int deriving (Show, Eq, Ord, Generic, NFData)
 
 data Quoted = Quoted | Unquoted deriving (Show, Eq)
 data Dashed = Dashed | Undashed deriving (Show, Eq)
+data Piped = Piped | Unpiped deriving (Show, Eq)
 data AssignmentMode = Assign | Append deriving (Show, Eq)
 newtype FunctionKeyword = FunctionKeyword Bool deriving (Show, Eq)
 newtype FunctionParentheses = FunctionParentheses Bool deriving (Show, Eq)
@@ -45,6 +46,7 @@ data InnerToken t =
     | Inner_TA_Variable String [t]
     | Inner_TA_Expansion [t]
     | Inner_TA_Sequence [t]
+    | Inner_TA_Parenthesis t
     | Inner_TA_Trinary t t t
     | Inner_TA_Unary String t
     | Inner_TC_And ConditionType String t t
@@ -83,7 +85,7 @@ data InnerToken t =
     | Inner_T_DollarDoubleQuoted [t]
     | Inner_T_DollarExpansion [t]
     | Inner_T_DollarSingleQuoted String
-    | Inner_T_DollarBraceCommandExpansion [t]
+    | Inner_T_DollarBraceCommandExpansion Piped [t]
     | Inner_T_Done
     | Inner_T_DoubleQuoted [t]
     | Inner_T_EOF
@@ -137,11 +139,11 @@ data InnerToken t =
     | Inner_T_WhileExpression [t] [t]
     | Inner_T_Annotation [Annotation] t
     | Inner_T_Pipe String
-    | Inner_T_CoProc (Maybe String) t
+    | Inner_T_CoProc (Maybe Token) t
     | Inner_T_CoProcBody t
     | Inner_T_Include t
     | Inner_T_SourceCommand t t
-    | Inner_T_BatsTest t t
+    | Inner_T_BatsTest String t
     deriving (Show, Eq, Functor, Foldable, Traversable)
 
 data Annotation =
@@ -150,6 +152,8 @@ data Annotation =
     | SourceOverride String
     | ShellOverride String
     | SourcePath String
+    | ExternalSources Bool
+    | ExtendedAnalysis Bool
     deriving (Show, Eq)
 data ConditionType = DoubleBracket | SingleBracket deriving (Show, Eq)
 
@@ -203,6 +207,7 @@ pattern T_Annotation id anns t = OuterToken id (Inner_T_Annotation anns t)
 pattern T_Arithmetic id c = OuterToken id (Inner_T_Arithmetic c)
 pattern T_Array id t = OuterToken id (Inner_T_Array t)
 pattern TA_Sequence id l = OuterToken id (Inner_TA_Sequence l)
+pattern TA_Parenthesis id t = OuterToken id (Inner_TA_Parenthesis t)
 pattern T_Assignment id mode var indices value = OuterToken id (Inner_T_Assignment mode var indices value)
 pattern TA_Trinary id t1 t2 t3 = OuterToken id (Inner_TA_Trinary t1 t2 t3)
 pattern TA_Unary id op t1 = OuterToken id (Inner_TA_Unary op t1)
@@ -224,7 +229,7 @@ pattern T_CoProc id var body = OuterToken id (Inner_T_CoProc var body)
 pattern TC_Or id typ str t1 t2 = OuterToken id (Inner_TC_Or typ str t1 t2)
 pattern TC_Unary id typ op token = OuterToken id (Inner_TC_Unary typ op token)
 pattern T_DollarArithmetic id c = OuterToken id (Inner_T_DollarArithmetic c)
-pattern T_DollarBraceCommandExpansion id list = OuterToken id (Inner_T_DollarBraceCommandExpansion list)
+pattern T_DollarBraceCommandExpansion id pipe list = OuterToken id (Inner_T_DollarBraceCommandExpansion pipe list)
 pattern T_DollarBraced id braced op = OuterToken id (Inner_T_DollarBraced braced op)
 pattern T_DollarBracket id c = OuterToken id (Inner_T_DollarBracket c)
 pattern T_DollarDoubleQuoted id list = OuterToken id (Inner_T_DollarDoubleQuoted list)
@@ -255,7 +260,7 @@ pattern T_Subshell id l = OuterToken id (Inner_T_Subshell l)
 pattern T_UntilExpression id c l = OuterToken id (Inner_T_UntilExpression c l)
 pattern T_WhileExpression id c l = OuterToken id (Inner_T_WhileExpression c l)
 
-{-# COMPLETE T_AND_IF, T_Bang, T_Case, TC_Empty, T_CLOBBER, T_DGREAT, T_DLESS, T_DLESSDASH, T_Do, T_DollarSingleQuoted, T_Done, T_DSEMI, T_Elif, T_Else, T_EOF, T_Esac, T_Fi, T_For, T_Glob, T_GREATAND, T_Greater, T_If, T_In, T_Lbrace, T_Less, T_LESSAND, T_LESSGREAT, T_Literal, T_Lparen, T_NEWLINE, T_OR_IF, T_ParamSubSpecialChar, T_Pipe, T_Rbrace, T_Rparen, T_Select, T_Semi, T_SingleQuoted, T_Then, T_UnparsedIndex, T_Until, T_While, TA_Assignment, TA_Binary, TA_Expansion, T_AndIf, T_Annotation, T_Arithmetic, T_Array, TA_Sequence, T_Assignment, TA_Trinary, TA_Unary, TA_Variable, T_Backgrounded, T_Backticked, T_Banged, T_BatsTest, T_BraceExpansion, T_BraceGroup, TC_And, T_CaseExpression, TC_Binary, TC_Group, TC_Nullary, T_Condition, T_CoProcBody, T_CoProc, TC_Or, TC_Unary, T_DollarArithmetic, T_DollarBraceCommandExpansion, T_DollarBraced, T_DollarBracket, T_DollarDoubleQuoted, T_DollarExpansion, T_DoubleQuoted, T_Extglob, T_FdRedirect, T_ForArithmetic, T_ForIn, T_Function, T_HereDoc, T_HereString, T_IfExpression, T_Include, T_IndexedElement, T_IoDuplicate, T_IoFile, T_NormalWord, T_OrIf, T_Pipeline, T_ProcSub, T_Redirecting, T_Script, T_SelectIn, T_SimpleCommand, T_SourceCommand, T_Subshell, T_UntilExpression, T_WhileExpression #-}
+{-# COMPLETE T_AND_IF, T_Bang, T_Case, TC_Empty, T_CLOBBER, T_DGREAT, T_DLESS, T_DLESSDASH, T_Do, T_DollarSingleQuoted, T_Done, T_DSEMI, T_Elif, T_Else, T_EOF, T_Esac, T_Fi, T_For, T_Glob, T_GREATAND, T_Greater, T_If, T_In, T_Lbrace, T_Less, T_LESSAND, T_LESSGREAT, T_Literal, T_Lparen, T_NEWLINE, T_OR_IF, T_ParamSubSpecialChar, T_Pipe, T_Rbrace, T_Rparen, T_Select, T_Semi, T_SingleQuoted, T_Then, T_UnparsedIndex, T_Until, T_While, TA_Assignment, TA_Binary, TA_Expansion, T_AndIf, T_Annotation, T_Arithmetic, T_Array, TA_Sequence, TA_Parenthesis, T_Assignment, TA_Trinary, TA_Unary, TA_Variable, T_Backgrounded, T_Backticked, T_Banged, T_BatsTest, T_BraceExpansion, T_BraceGroup, TC_And, T_CaseExpression, TC_Binary, TC_Group, TC_Nullary, T_Condition, T_CoProcBody, T_CoProc, TC_Or, TC_Unary, T_DollarArithmetic, T_DollarBraceCommandExpansion, T_DollarBraced, T_DollarBracket, T_DollarDoubleQuoted, T_DollarExpansion, T_DoubleQuoted, T_Extglob, T_FdRedirect, T_ForArithmetic, T_ForIn, T_Function, T_HereDoc, T_HereString, T_IfExpression, T_Include, T_IndexedElement, T_IoDuplicate, T_IoFile, T_NormalWord, T_OrIf, T_Pipeline, T_ProcSub, T_Redirecting, T_Script, T_SelectIn, T_SimpleCommand, T_SourceCommand, T_Subshell, T_UntilExpression, T_WhileExpression #-}
 
 instance Eq Token where
     OuterToken _ a == OuterToken _ b = a == b

src/ShellCheck/ASTLib.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2019 Vidar Holen
+    Copyright 2012-2021 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -17,9 +17,12 @@
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.
 -}
+{-# LANGUAGE TemplateHaskell #-}
 module ShellCheck.ASTLib where
 
 import ShellCheck.AST
+import ShellCheck.Prelude
+import ShellCheck.Regex
 
 import Control.Monad.Writer
 import Control.Monad
@@ -28,9 +31,12 @@ import Data.Functor
 import Data.Functor.Identity
 import Data.List
 import Data.Maybe
+import qualified Data.List.NonEmpty as NE
 import qualified Data.Map as Map
 import Numeric (showHex)
 
+import Test.QuickCheck
+
 arguments (T_SimpleCommand _ _ (cmd:args)) = args
 
 -- Is this a type of loop?
@@ -55,10 +61,28 @@ willSplit x =
     T_NormalWord _ l -> any willSplit l
     _ -> False
 
-isGlob T_Extglob {} = True
+isGlob t = case t of
-isGlob T_Glob {} = True
+    T_Extglob {} -> True
-isGlob (T_NormalWord _ l) = any isGlob l
+    T_Glob {} -> True
-isGlob _ = False
+    T_NormalWord _ l -> any isGlob l || hasSplitRange l
+    _ -> False
+  where
+    -- foo[x${var}y] gets parsed as foo,[,x,$var,y],
+    -- so check if there's such an interval
+    hasSplitRange l =
+        let afterBracket = dropWhile (not . isHalfOpenRange) l
+        in any isClosingRange afterBracket
+
+    isHalfOpenRange t =
+        case t of
+            T_Literal _ "[" -> True
+            _ -> False
+
+    isClosingRange t =
+        case t of
+            T_Literal _ str -> ']' `elem` str
+            _ -> False
+
 
 -- Is this shell word a constant?
 isConstant token =
@@ -116,7 +140,7 @@ getFlagsUntil stopCondition (T_SimpleCommand _ _ (_:args)) =
     flag (x, '-':'-':arg) = [ (x, takeWhile (/= '=') arg) ]
     flag (x, '-':args) = map (\v -> (x, [v])) args
     flag (x, _) = [ (x, "") ]
-getFlagsUntil _ _ = error "Internal shellcheck error, please report! (getFlags on non-command)"
+getFlagsUntil _ _ = error $ pleaseReport "getFlags on non-command"
 
 -- Get all flags in a GNU way, up until --
 getAllFlags :: Token -> [(Token, String)]
@@ -134,9 +158,10 @@ isFlag token =
         _ -> False
 
 -- Is this token a flag where the - is unquoted?
-isUnquotedFlag token = fromMaybe False $ do
+isUnquotedFlag token =
-    str <- getLeadingUnquotedString token
+    case getLeadingUnquotedString token of
-    return $ "-" `isPrefixOf` str
+        Just ('-':_) -> True
+        _ -> False
 
 -- getGnuOpts "erd:u:" will parse a list of arguments tokens like `read`
 --     -re -d : -u 3 bar
@@ -224,6 +249,39 @@ getOpts (gnu, arbitraryLongOpts) string longopts args = process args
 
     listToArgs = map (\x -> ("", (x, x)))
 
+
+-- Generic getOpts that doesn't rely on a format string, but may also be inaccurate.
+-- This provides a best guess interpretation instead of failing when new options are added.
+--
+--    "--" is treated as end of arguments
+--    "--anything[=foo]" is treated as a long option without argument
+--    "-any" is treated as -a -n -y, with the next arg as an option to -y unless it starts with -
+--    anything else is an argument
+getGenericOpts :: [Token] -> [(String, (Token, Token))]
+getGenericOpts = process
+  where
+    process (token:rest) =
+        case getLiteralStringDef "\0" token of
+            "--" -> map (\c -> ("", (c,c))) rest
+            '-':'-':word -> (takeWhile (`notElem` "\0=") word, (token, token)) : process rest
+            '-':optString ->
+                let opts = takeWhile (/= '\0') optString
+                in
+                    case rest of
+                        next:_ | "-" `isPrefixOf` getLiteralStringDef "\0" next  ->
+                            map (\c -> ([c], (token, token))) opts ++ process rest
+                        next:remainder ->
+                            case reverse opts of
+                                last:initial ->
+                                    map (\c -> ([c], (token, token))) (reverse initial)
+                                        ++ [([last], (token, next))]
+                                        ++ process remainder
+                                [] -> process remainder
+                        [] -> map (\c -> ([c], (token, token))) opts
+            _ -> ("", (token, token)) : process rest
+    process [] = []
+
+
 -- Is this an expansion of multiple items of an array?
 isArrayExpansion (T_DollarBraced _ _ l) =
     let string = concat $ oversimplify l in
@@ -232,14 +290,14 @@ isArrayExpansion (T_DollarBraced _ _ l) =
 isArrayExpansion _ = False
 
 -- Is it possible that this arg becomes multiple args?
-mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f t
+mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f False t
   where
-    f (T_DollarBraced _ _ l) =
+    f quoted (T_DollarBraced _ _ l) =
         let string = concat $ oversimplify l in
-            "!" `isPrefixOf` string
+            not quoted || "!" `isPrefixOf` string
-    f (T_DoubleQuoted _ parts) = any f parts
+    f quoted (T_DoubleQuoted _ parts) = any (f True) parts
-    f (T_NormalWord _ parts) = any f parts
+    f quoted (T_NormalWord _ parts) = any (f quoted) parts
-    f _ = False
+    f _ _ = False
 
 -- Is it certain that this word will becomes multiple words?
 willBecomeMultipleArgs t = willConcatInAssignment t || f t
@@ -247,7 +305,6 @@ willBecomeMultipleArgs t = willConcatInAssignment t || f t
     f T_Extglob {} = True
     f T_Glob {} = True
     f T_BraceExpansion {} = True
-    f (T_DoubleQuoted _ parts) = any f parts
     f (T_NormalWord _ parts) = any f parts
     f _ = False
 
@@ -315,6 +372,21 @@ getGlobOrLiteralString = getLiteralStringExt f
     f (T_Glob _ str) = return str
     f _ = Nothing
 
+
+prop_getLiteralString1 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x01") == Just "\1"
+prop_getLiteralString2 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\xyz") == Just "\\xyz"
+prop_getLiteralString3 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x1") == Just "\x1"
+prop_getLiteralString4 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x1y") == Just "\x1y"
+prop_getLiteralString5 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\xy") == Just "\\xy"
+prop_getLiteralString6 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\x") == Just "\\x"
+prop_getLiteralString7 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\1x") == Just "\1x"
+prop_getLiteralString8 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\12x") == Just "\o12x"
+prop_getLiteralString9 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\123x") == Just "\o123x"
+prop_getLiteralString10 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\1234") == Just "\o123\&4"
+prop_getLiteralString11 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\1") == Just "\1"
+prop_getLiteralString12 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\12") == Just "\o12"
+prop_getLiteralString13 = getLiteralString (T_DollarSingleQuoted (Id 0) "\\123") == Just "\o123"
+
 -- Maybe get the literal value of a token, using a custom function
 -- to map unrecognized Tokens into strings.
 getLiteralStringExt :: Monad m => (Token -> m String) -> Token -> m String
@@ -347,14 +419,15 @@ getLiteralStringExt more = g
             '\\' -> '\\' : rest
             'x' ->
                 case cs of
-                    (x:y:more) ->
+                    (x:y:more) | isHexDigit x && isHexDigit y ->
-                        if isHexDigit x && isHexDigit y
+                        chr (16*(digitToInt x) + (digitToInt y)) : decodeEscapes more
-                        then chr (16*(digitToInt x) + (digitToInt y)) : rest
+                    (x:more) | isHexDigit x ->
-                        else '\\':c:rest
+                        chr (digitToInt x) : decodeEscapes more
+                    more -> '\\' : 'x' : decodeEscapes more
             _ | isOctDigit c ->
-                let digits = take 3 $ takeWhile isOctDigit (c:cs)
+                let (digits, more) = spanMax isOctDigit 3 (c:cs)
-                    num = parseOct digits
+                    num = (parseOct digits) `mod` 256
-                in (if num < 256 then chr num else '?') : rest
+                in (chr num) : decodeEscapes more
             _ -> '\\' : c : rest
       where
         rest = decodeEscapes cs
@@ -362,12 +435,23 @@ getLiteralStringExt more = g
           where
             f n "" = n
             f n (c:rest) = f (n * 8 + digitToInt c) rest
+        spanMax f n list =
+            let (first, second) = span f list
+                (prefix, suffix) = splitAt n first
+            in
+                (prefix, suffix ++ second)
     decodeEscapes (c:cs) = c : decodeEscapes cs
     decodeEscapes [] = []
 
 -- Is this token a string literal?
 isLiteral t = isJust $ getLiteralString t
 
+-- Is this token a string literal number?
+isLiteralNumber t = fromMaybe False $ do
+    s <- getLiteralString t
+    guard $ all isDigit s
+    return True
+
 -- Escape user data for messages.
 -- Messages generally avoid repeating user data, but sometimes it's helpful.
 e4m = escapeForMessage
@@ -477,7 +561,7 @@ getCommandNameFromExpansion t =
     case t of
         T_DollarExpansion _ [c] -> extract c
         T_Backticked _ [c] -> extract c
-        T_DollarBraceCommandExpansion _ [c] -> extract c
+        T_DollarBraceCommandExpansion _ _ [c] -> extract c
         _ -> Nothing
   where
     extract (T_Pipeline _ _ [cmd]) = getCommandName cmd
@@ -532,7 +616,7 @@ getCommandSequences t =
         T_Annotation _ _ t -> getCommandSequences t
 
         T_DollarExpansion _ cmds -> [cmds]
-        T_DollarBraceCommandExpansion _ cmds -> [cmds]
+        T_DollarBraceCommandExpansion _ _ cmds -> [cmds]
         T_Backticked _ cmds -> [cmds]
         _ -> []
 
@@ -672,3 +756,171 @@ isAnnotationIgnoringCode code t =
   where
     hasNum (DisableComment from to) = code >= from && code < to
     hasNum _                   = False
+
+prop_executableFromShebang1 = executableFromShebang "/bin/sh" == "sh"
+prop_executableFromShebang2 = executableFromShebang "/bin/bash" == "bash"
+prop_executableFromShebang3 = executableFromShebang "/usr/bin/env ksh" == "ksh"
+prop_executableFromShebang4 = executableFromShebang "/usr/bin/env -S foo=bar bash -x" == "bash"
+prop_executableFromShebang5 = executableFromShebang "/usr/bin/env --split-string=bash -x" == "bash"
+prop_executableFromShebang6 = executableFromShebang "/usr/bin/env --split-string=foo=bar bash -x" == "bash"
+prop_executableFromShebang7 = executableFromShebang "/usr/bin/env --split-string bash -x" == "bash"
+prop_executableFromShebang8 = executableFromShebang "/usr/bin/env --split-string foo=bar bash -x" == "bash"
+prop_executableFromShebang9 = executableFromShebang "/usr/bin/env foo=bar dash" == "dash"
+prop_executableFromShebang10 = executableFromShebang "/bin/busybox sh" == "busybox sh"
+prop_executableFromShebang11 = executableFromShebang "/bin/busybox ash" == "busybox ash"
+
+-- Get the shell executable from a string like '/usr/bin/env bash'
+executableFromShebang :: String -> String
+executableFromShebang = shellFor
+  where
+    re = mkRegex "/env +(-S|--split-string=?)? *(.*)"
+    shellFor s | s `matches` re =
+        case matchRegex re s of
+            Just [flag, shell] -> fromEnvArgs (words shell)
+            _ -> ""
+    shellFor sb =
+        case words sb of
+            [] -> ""
+            [x] -> basename x
+            (first:second:args) | basename first == "busybox" ->
+                case basename second of
+                   "sh" -> "busybox sh"
+                   "ash" -> "busybox ash"
+                   x -> x
+            (first:args) | basename first == "env" ->
+                fromEnvArgs args
+            (first:_) -> basename first
+
+    fromEnvArgs args = fromMaybe "" $ find (notElem '=') $ skipFlags args
+    basename s = reverse . takeWhile (/= '/') . reverse $ s
+    skipFlags = dropWhile ("-" `isPrefixOf`)
+
+
+-- Determining if a name is a variable
+isVariableStartChar x = x == '_' || isAsciiLower x || isAsciiUpper x
+isVariableChar x = isVariableStartChar x || isDigit x
+isSpecialVariableChar = (`elem` "*@#?-$!")
+variableNameRegex = mkRegex "[_a-zA-Z][_a-zA-Z0-9]*"
+
+prop_isVariableName1 = isVariableName "_fo123"
+prop_isVariableName2 = not $ isVariableName "4"
+prop_isVariableName3 = not $ isVariableName "test: "
+isVariableName (x:r) = isVariableStartChar x && all isVariableChar r
+isVariableName _     = False
+
+
+-- Get the variable name from an expansion like ${var:-foo}
+prop_getBracedReference1 = getBracedReference "foo" == "foo"
+prop_getBracedReference2 = getBracedReference "#foo" == "foo"
+prop_getBracedReference3 = getBracedReference "#" == "#"
+prop_getBracedReference4 = getBracedReference "##" == "#"
+prop_getBracedReference5 = getBracedReference "#!" == "!"
+prop_getBracedReference6 = getBracedReference "!#" == "#"
+prop_getBracedReference7 = getBracedReference "!foo#?" == "foo"
+prop_getBracedReference8 = getBracedReference "foo-bar" == "foo"
+prop_getBracedReference9 = getBracedReference "foo:-bar" == "foo"
+prop_getBracedReference10 = getBracedReference "foo: -1" == "foo"
+prop_getBracedReference11 = getBracedReference "!os*" == ""
+prop_getBracedReference11b = getBracedReference "!os@" == ""
+prop_getBracedReference12 = getBracedReference "!os?bar**" == ""
+prop_getBracedReference13 = getBracedReference "foo[bar]" == "foo"
+getBracedReference s = fromMaybe s $
+    nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
+  where
+    noPrefix = dropPrefix s
+    dropPrefix (c:rest) | c `elem` "!#" = rest
+    dropPrefix cs = cs
+    takeName s = do
+        let name = takeWhile isVariableChar s
+        guard . not $ null name
+        return name
+    getSpecial (c:_) | isSpecialVariableChar c = return [c]
+    getSpecial _ = fail "empty or not special"
+
+    nameExpansion ('!':next:rest) = do -- e.g. ${!foo*bar*}
+        guard $ isVariableChar next -- e.g. ${!@}
+        first <- find (not . isVariableChar) rest
+        guard $ first `elem` "*?@"
+        return ""
+    nameExpansion _ = Nothing
+
+-- Get the variable modifier like /a/b in ${var/a/b}
+prop_getBracedModifier1 = getBracedModifier "foo:bar:baz" == ":bar:baz"
+prop_getBracedModifier2 = getBracedModifier "!var:-foo" == ":-foo"
+prop_getBracedModifier3 = getBracedModifier "foo[bar]" == "[bar]"
+prop_getBracedModifier4 = getBracedModifier "foo[@]@Q" == "[@]@Q"
+prop_getBracedModifier5 = getBracedModifier "@@Q" == "@Q"
+getBracedModifier s = headOrDefault "" $ do
+    let var = getBracedReference s
+    a <- dropModifier s
+    dropPrefix var a
+  where
+    dropPrefix [] t        = return t
+    dropPrefix (a:b) (c:d) | a == c = dropPrefix b d
+    dropPrefix _ _         = []
+
+    dropModifier (c:rest) | c `elem` "#!" = [rest, c:rest]
+    dropModifier x        = [x]
+
+-- Get the variables from indices like ["x", "y"] in ${var[x+y+1]}
+prop_getIndexReferences1 = getIndexReferences "var[x+y+1]" == ["x", "y"]
+getIndexReferences s = fromMaybe [] $ do
+    index:_ <- matchRegex re s
+    return $ matchAllStrings variableNameRegex index
+  where
+    re = mkRegex "(\\[.*\\])"
+
+prop_getOffsetReferences1 = getOffsetReferences ":bar" == ["bar"]
+prop_getOffsetReferences2 = getOffsetReferences ":bar:baz" == ["bar", "baz"]
+prop_getOffsetReferences3 = getOffsetReferences "[foo]:bar" == ["bar"]
+prop_getOffsetReferences4 = getOffsetReferences "[foo]:bar:baz" == ["bar", "baz"]
+getOffsetReferences mods = fromMaybe [] $ do
+-- if mods start with [, then drop until ]
+    _:offsets:_ <- matchRegex re mods
+    return $ matchAllStrings variableNameRegex offsets
+  where
+    re = mkRegex "^(\\[.+\\])? *:([^-=?+].*)"
+
+
+-- Returns whether a token is a parameter expansion without any modifiers.
+-- True for $var ${var} $1 $#
+-- False for ${#var} ${var[x]} ${var:-0}
+isUnmodifiedParameterExpansion t =
+    case t of
+        T_DollarBraced _ False _ -> True
+        T_DollarBraced _ _ list ->
+            let str = concat $ oversimplify list
+            in getBracedReference str == str
+        _ -> False
+
+-- Return the referenced variable if (and only if) it's an unmodified parameter expansion.
+getUnmodifiedParameterExpansion t =
+    case t of
+        T_DollarBraced _ _ list -> do
+            let str = concat $ oversimplify list
+            guard $ getBracedReference str == str
+            return str
+        _ -> Nothing
+
+--- A list of the element and all its parents up to the root node.
+getPath tree = NE.unfoldr $ \t -> (t, Map.lookup (getId t) tree)
+
+isClosingFileOp op =
+    case op of
+        T_IoDuplicate _ (T_GREATAND _) "-" -> True
+        T_IoDuplicate _ (T_LESSAND  _) "-" -> True
+        _                                  -> False
+
+getEnableDirectives root =
+    case root of
+        T_Annotation _ list _ -> [s | EnableComment s <- list]
+        _ -> []
+
+getExtendedAnalysisDirective :: Token -> Maybe Bool
+getExtendedAnalysisDirective root =
+    case root of
+        T_Annotation _ list _ -> listToMaybe $ [s | ExtendedAnalysis s <- list]
+        _ -> Nothing
+
+return []
+runTests = $quickCheckAll

src/ShellCheck/Analyzer.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2019 Vidar Holen
+    Copyright 2012-2022 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -25,6 +25,7 @@ import ShellCheck.Interface
 import Data.List
 import Data.Monoid
 import qualified ShellCheck.Checks.Commands
+import qualified ShellCheck.Checks.ControlFlow
 import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
 
@@ -34,19 +35,21 @@ analyzeScript :: AnalysisSpec -> AnalysisResult
 analyzeScript spec = newAnalysisResult {
     arComments =
         filterByAnnotation spec params . nub $
-            runAnalytics spec
+            runChecker params (checkers spec params)
-            ++ runChecker params (checkers spec params)
 }
   where
     params = makeParameters spec
 
 checkers spec params = mconcat $ map ($ params) [
+    ShellCheck.Analytics.checker spec,
     ShellCheck.Checks.Commands.checker spec,
+    ShellCheck.Checks.ControlFlow.checker spec,
     ShellCheck.Checks.Custom.checker,
     ShellCheck.Checks.ShellSupport.checker
     ]
 
 optionalChecks = mconcat $ [
     ShellCheck.Analytics.optionalChecks,
-    ShellCheck.Checks.Commands.optionalChecks
+    ShellCheck.Checks.Commands.optionalChecks,
+    ShellCheck.Checks.ControlFlow.optionalChecks
     ]

src/ShellCheck/AnalyzerLib.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2019 Vidar Holen
+    Copyright 2012-2022 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -23,13 +23,16 @@ module ShellCheck.AnalyzerLib where
 
 import ShellCheck.AST
 import ShellCheck.ASTLib
+import qualified ShellCheck.CFGAnalysis as CF
 import ShellCheck.Data
 import ShellCheck.Interface
 import ShellCheck.Parser
+import ShellCheck.Prelude
 import ShellCheck.Regex
 
 import Control.Arrow (first)
 import Control.DeepSeq
+import Control.Monad
 import Control.Monad.Identity
 import Control.Monad.RWS
 import Control.Monad.State
@@ -38,6 +41,7 @@ import Data.Char
 import Data.List
 import Data.Maybe
 import Data.Semigroup
+import qualified Data.List.NonEmpty as NE
 import qualified Data.Map as Map
 
 import Test.QuickCheck.All (forAllProperties)
@@ -79,10 +83,18 @@ composeAnalyzers f g x = f x >> g x
 data Parameters = Parameters {
     -- Whether this script has the 'lastpipe' option set/default.
     hasLastpipe        :: Bool,
+    -- Whether this script has the 'inherit_errexit' option set/default.
+    hasInheritErrexit  :: Bool,
     -- Whether this script has 'set -e' anywhere.
     hasSetE            :: Bool,
+    -- Whether this script has 'set -o pipefail' anywhere.
+    hasPipefail        :: Bool,
+    -- Whether this script has 'shopt -s execfail' anywhere.
+    hasExecfail        :: Bool,
     -- A linear (bad) analysis of data flow
     variableFlow       :: [StackData],
+    -- A map from Id to Token
+    idMap              :: Map.Map Id Token,
     -- A map from Id to parent Token
     parentMap          :: Map.Map Id Token,
     -- The shell type, such as Bash or Ksh
@@ -92,7 +104,9 @@ data Parameters = Parameters {
     -- The root node of the AST
     rootNode           :: Token,
     -- map from token id to start and end position
-    tokenPositions     :: Map.Map Id (Position, Position)
+    tokenPositions     :: Map.Map Id (Position, Position),
+    -- Result from Control Flow Graph analysis (including data flow analysis)
+    cfgAnalysis :: Maybe CF.CFGAnalysis
     } deriving (Show)
 
 -- TODO: Cache results of common AST ops here
@@ -142,7 +156,7 @@ producesComments c s = do
         prRoot pr
         let spec = defaultSpec pr
         let params = makeParameters spec
-        return . not . null $ runChecker params c
+        return . not . null $ filterByAnnotation spec params $ runChecker params c
 
 makeComment :: Severity -> Id -> Code -> String -> TokenComment
 makeComment severity id code note =
@@ -167,6 +181,8 @@ errWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m (
 errWithFix  = addCommentWithFix ErrorC
 warnWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
 warnWithFix  = addCommentWithFix WarningC
+infoWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
+infoWithFix = addCommentWithFix InfoC
 styleWithFix :: MonadWriter [TokenComment] m => Id -> Code -> String -> Fix -> m ()
 styleWithFix = addCommentWithFix StyleC
 
@@ -178,28 +194,58 @@ makeCommentWithFix :: Severity -> Id -> Code -> String -> Fix -> TokenComment
 makeCommentWithFix severity id code str fix =
     let comment = makeComment severity id code str
         withFix = comment {
-            tcFix = Just fix
+            -- If fix is empty, pretend it wasn't there.
+            tcFix = if null (fixReplacements fix) then Nothing else Just fix
         }
     in force withFix
 
-makeParameters spec =
+-- makeParameters :: CheckSpec -> Parameters
-    let params = Parameters {
+makeParameters spec = params
+  where
+    extendedAnalysis = fromMaybe True $ msum [asExtendedAnalysis spec, getExtendedAnalysisDirective root]
+    params = Parameters {
         rootNode = root,
         shellType = fromMaybe (determineShell (asFallbackShell spec) root) $ asShellType spec,
         hasSetE = containsSetE root,
         hasLastpipe =
             case shellType params of
-                Bash -> containsLastpipe root
+                Bash -> isOptionSet "lastpipe" root
                 Dash -> False
+                BusyboxSh -> False
                 Sh   -> False
                 Ksh  -> True,
-
+        hasInheritErrexit =
+            case shellType params of
+                Bash -> isOptionSet "inherit_errexit" root
+                Dash -> True
+                BusyboxSh -> True
+                Sh   -> True
+                Ksh  -> False,
+        hasPipefail =
+            case shellType params of
+                Bash -> isOptionSet "pipefail" root
+                Dash -> True
+                BusyboxSh -> isOptionSet "pipefail" root
+                Sh   -> True
+                Ksh  -> isOptionSet "pipefail" root,
+        hasExecfail =
+            case shellType params of
+                Bash -> isOptionSet "execfail" root
+                _ -> False,
         shellTypeSpecified = isJust (asShellType spec) || isJust (asFallbackShell spec),
+        idMap = getTokenMap root,
         parentMap = getParentTree root,
         variableFlow = getVariableFlow params root,
-        tokenPositions = asTokenPositions spec
+        tokenPositions = asTokenPositions spec,
-    } in params
+        cfgAnalysis = do
-  where root = asScript spec
+            guard extendedAnalysis
+            return $ CF.analyzeControlFlow cfParams root
+    }
+    cfParams = CF.CFGParameters {
+        CF.cfLastpipe = hasLastpipe params,
+        CF.cfPipefail = hasPipefail params
+    }
+    root = asScript spec
 
 
 -- Does this script mention 'set -e' anywhere?
@@ -216,18 +262,30 @@ containsSetE root = isNothing $ doAnalysis (guard . not . isSetE) root
             _ -> False
     re = mkRegex "[[:space:]]-[^-]*e"
 
--- Does this script mention 'shopt -s lastpipe' anywhere?
+
--- Also used as a hack.
+containsSetOption opt root = isNothing $ doAnalysis (guard . not . isPipefail) root
-containsLastpipe root =
+  where
+    isPipefail t =
+        case t of
+            T_SimpleCommand {}  ->
+                t `isUnqualifiedCommand` "set" &&
+                    (opt `elem` oversimplify t ||
+                        "o" `elem` map snd (getAllFlags t))
+            _ -> False
+
+containsShopt shopt root =
         isNothing $ doAnalysis (guard . not . isShoptLastPipe) root
     where
         isShoptLastPipe t =
             case t of
                 T_SimpleCommand {}  ->
                     t `isUnqualifiedCommand` "shopt" &&
-                        ("lastpipe" `elem` oversimplify t)
+                        (shopt `elem` oversimplify t)
                 _ -> False
 
+-- Does this script mention 'shopt -s $opt' or 'set -o $opt' anywhere?
+isOptionSet opt root = containsShopt opt root || containsSetOption opt root
+
 
 prop_determineShell0 = determineShellTest "#!/bin/sh" == Sh
 prop_determineShell1 = determineShellTest "#!/usr/bin/env ksh" == Ksh
@@ -240,6 +298,8 @@ prop_determineShell7 = determineShellTest "#! /bin/ash" == Dash
 prop_determineShell8 = determineShellTest' (Just Ksh) "#!/bin/sh" == Sh
 prop_determineShell9 = determineShellTest "#!/bin/env -S dash -x" == Dash
 prop_determineShell10 = determineShellTest "#!/bin/env --split-string= dash -x" == Dash
+prop_determineShell11 = determineShellTest "#!/bin/busybox sh" == BusyboxSh -- busybox sh is a specific shell, not posix sh
+prop_determineShell12 = determineShellTest "#!/bin/busybox ash" == BusyboxSh
 
 determineShellTest = determineShellTest' Nothing
 determineShellTest' fallbackShell = determineShell fallbackShell . fromJust . prRoot . pScript
@@ -253,19 +313,6 @@ determineShell fallbackShell t = fromMaybe Bash $
         headOrDefault (fromShebang s) [s | ShellOverride s <- annotations]
     fromShebang (T_Script _ (T_Literal _ s) _) = executableFromShebang s
 
--- Given a string like "/bin/bash" or "/usr/bin/env dash",
--- return the shell basename like "bash" or "dash"
-executableFromShebang :: String -> String
-executableFromShebang = shellFor
-  where
-    shellFor s | "/env " `isInfixOf` s = case matchRegex re s of
-        Just [flag, shell] -> shell
-        _ -> ""
-    shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
-    shellFor s = reverse . takeWhile (/= '/') . reverse $ s
-    re = mkRegex "/env +(-S|--split-string=?)? *([^ ]*)"
-
-
 -- Given a root node, make a map from Id to parent Token.
 -- This is used to populate parentMap in Parameters
 getParentTree :: Token -> Map.Map Id Token
@@ -298,16 +345,16 @@ isStrictlyQuoteFree = isQuoteFreeNode True
 isQuoteFree = isQuoteFreeNode False
 
 
-isQuoteFreeNode strict tree t =
+isQuoteFreeNode strict shell tree t =
     isQuoteFreeElement t ||
-        headOrDefault False (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t))
+        (fromMaybe False $ msum $ map isQuoteFreeContext $ NE.tail $ getPath tree t)
   where
     -- Is this node self-quoting in itself?
     isQuoteFreeElement t =
         case t of
-            T_Assignment {} -> True
+            T_Assignment id _ _ _ _ -> assignmentIsQuoting id
-            T_FdRedirect {} -> True
+            T_FdRedirect {}         -> True
-            _               -> False
+            _                       -> False
 
     -- Are any subnodes inherently self-quoting?
     isQuoteFreeContext t =
@@ -317,7 +364,7 @@ isQuoteFreeNode strict tree t =
             TC_Binary _ DoubleBracket _ _ _ -> return True
             TA_Sequence {}                  -> return True
             T_Arithmetic {}                 -> return True
-            T_Assignment {}                 -> return True
+            T_Assignment id _ _ _ _         -> return $ assignmentIsQuoting id
             T_Redirecting {}                -> return False
             T_DoubleQuoted _ _              -> return True
             T_DollarDoubleQuoted _ _        -> return True
@@ -329,6 +376,18 @@ isQuoteFreeNode strict tree t =
             T_SelectIn {}                   -> return (not strict)
             _                               -> Nothing
 
+    -- Check whether this assignment is self-quoting due to being a recognized
+    -- assignment passed to a Declaration Utility. This will soon be required
+    -- by POSIX: https://austingroupbugs.net/view.php?id=351
+    assignmentIsQuoting id = shellParsesParamsAsAssignments || not (isAssignmentParamToCommand id)
+    shellParsesParamsAsAssignments = shell /= Sh
+
+    -- Is this assignment a parameter to a command like export/typeset/etc?
+    isAssignmentParamToCommand id =
+        case Map.lookup id tree of
+            Just (T_SimpleCommand _ _ (_:args)) -> id `elem` (map getId args)
+            _ -> False
+
 -- Check if a token is a parameter to a certain command by name:
 -- Example: isParamTo (parentMap params) "sed" t
 isParamTo :: Map.Map Id Token -> String -> Token -> Bool
@@ -350,7 +409,7 @@ isParamTo tree cmd =
 -- Get the parent command (T_Redirecting) of a Token, if any.
 getClosestCommand :: Map.Map Id Token -> Token -> Maybe Token
 getClosestCommand tree t =
-    findFirst findCommand $ getPath tree t
+    findFirst findCommand $ NE.toList $ getPath tree t
   where
     findCommand t =
         case t of
@@ -364,7 +423,7 @@ getClosestCommandM t = do
     return $ getClosestCommand (parentMap params) t
 
 -- Is the token used as a command name (the first word in a T_SimpleCommand)?
-usedAsCommandName tree token = go (getId token) (tail $ getPath tree token)
+usedAsCommandName tree token = go (getId token) (NE.tail $ getPath tree token)
   where
     go currentId (T_NormalWord id [word]:rest)
         | currentId == getId word = go id rest
@@ -374,12 +433,6 @@ usedAsCommandName tree token = go (getId token) (tail $ getPath tree token)
         getId word == currentId || getId (getCommandTokenOrThis t) == currentId
     go _ _ = False
 
--- A list of the element and all its parents up to the root node.
-getPath tree t = t :
-    case Map.lookup (getId t) tree of
-        Nothing     -> []
-        Just parent -> getPath tree parent
-
 -- Version of the above taking the map from the current context
 -- Todo: give this the name "getPath"
 getPathM t = do
@@ -387,7 +440,9 @@ getPathM t = do
     return $ getPath (parentMap params) t
 
 isParentOf tree parent child =
-    elem (getId parent) . map getId $ getPath tree child
+    any (\t -> parentId == getId t) (getPath tree child)
+  where
+    parentId = getId parent
 
 parents params = getPath (parentMap params)
 
@@ -477,30 +532,24 @@ getModifiedVariables t =
         T_SimpleCommand {} ->
             getModifiedVariableCommand t
 
-        TA_Unary _ "++|" v@(TA_Variable _ name _)  ->
+        TA_Unary _ op v@(TA_Variable _ name _) | "--" `isInfixOf` op || "++" `isInfixOf` op ->
-            [(t, v, name, DataString $ SourceFrom [v])]
+            [(t, v, name, DataString SourceInteger)]
-        TA_Unary _ "|++" v@(TA_Variable _ name _)  ->
-            [(t, v, name, DataString $ SourceFrom [v])]
         TA_Assignment _ op (TA_Variable _ name _) rhs -> do
             guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
-            return (t, t, name, DataString $ SourceFrom [rhs])
+            return (t, t, name, DataString SourceInteger)
 
         T_BatsTest {} -> [
             (t, t, "lines", DataArray SourceExternal),
             (t, t, "status", DataString SourceInteger),
-            (t, t, "output", DataString SourceExternal)
+            (t, t, "output", DataString SourceExternal),
+            (t, t, "stderr", DataString SourceExternal),
+            (t, t, "stderr_lines", DataArray SourceExternal)
             ]
 
         -- Count [[ -v foo ]] as an "assignment".
         -- This is to prevent [ -v foo ] being unassigned or unused.
-        TC_Unary id _ "-v" token -> do
+        TC_Unary id _ "-v" token -> maybeToList $ do
-            str <- fmap (takeWhile (/= '[')) $ -- Quoted index
+            str <- getVariableForTestDashV token
-                    flip getLiteralStringExt token $ \x ->
-                case x of
-                    T_Glob _ s -> return s -- Unquoted index
-                    _          -> []
-
-            guard . not . null $ str
             return (t, token, str, DataString SourceChecked)
 
         TC_Unary _ _ "-n" token -> markAsChecked t token
@@ -516,8 +565,12 @@ getModifiedVariables t =
         T_FdRedirect _ ('{':var) op -> -- {foo}>&2 modifies foo
             [(t, t, takeWhile (/= '}') var, DataString SourceInteger) | not $ isClosingFileOp op]
 
-        T_CoProc _ name _ ->
+        T_CoProc _ Nothing _ ->
-            [(t, t, fromMaybe "COPROC" name, DataArray SourceInteger)]
+            [(t, t, "COPROC", DataArray SourceInteger)]
+
+        T_CoProc _ (Just token) _ -> do
+            name <- maybeToList $ getLiteralString token
+            [(t, t, name, DataArray SourceInteger)]
 
         --Points to 'for' rather than variable
         T_ForIn id str [] _ -> [(t, t, str, DataString SourceExternal)]
@@ -533,24 +586,16 @@ getModifiedVariables t =
                     return (place, t, str, DataString SourceChecked)
             _ -> Nothing
 
-isClosingFileOp op =
-    case op of
-        T_IoDuplicate _ (T_GREATAND _) "-" -> True
-        T_IoDuplicate _ (T_LESSAND  _) "-" -> True
-        _                                  -> False
-
 
 -- Consider 'export/declare -x' a reference, since it makes the var available
 getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
     case x of
+        "declare" -> forDeclare
+        "typeset" -> forDeclare
+
         "export" -> if "f" `elem` flags
             then []
             else concatMap getReference rest
-        "declare" -> if
-                any (`elem` flags) ["x", "p"] &&
-                    (not $ any (`elem` flags) ["f", "F"])
-            then concatMap getReference rest
-            else []
         "local" -> if "x" `elem` flags
             then concatMap getReference rest
             else []
@@ -561,6 +606,13 @@ getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Litera
         "alias" -> [(base, token, name) | token <- rest, name <- getVariablesFromLiteralToken token]
         _ -> []
   where
+    forDeclare =
+            if
+                any (`elem` flags) ["x", "p"] &&
+                    (not $ any (`elem` flags) ["f", "F"])
+            then concatMap getReference rest
+            else []
+
     getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)]
     getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)]
     getReference _ = []
@@ -600,8 +652,8 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
         "export" ->
             if "f" `elem` flags then [] else concatMap getModifierParamString rest
 
-        "declare" -> if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
+        "declare" -> forDeclare
-        "typeset" -> declaredVars
+        "typeset" -> forDeclare
 
         "local" -> concatMap getModifierParamString rest
         "readonly" ->
@@ -613,6 +665,7 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
             return (base, base, "@", DataString $ SourceFrom params)
 
         "printf" -> maybeToList $ getPrintfVariable rest
+        "wait" ->   maybeToList $ getWaitVariable rest
 
         "mapfile" -> maybeToList $ getMapfileArray base rest
         "readarray" -> maybeToList $ getMapfileArray base rest
@@ -632,6 +685,8 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
         T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 (stripEquals s)]]
     stripEqualsFrom t = t
 
+    forDeclare = if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
+
     declaredVars = concatMap (getModifierParam defaultType) rest
       where
         defaultType = if any (`elem` flags) ["a", "A"] then DataArray else DataString
@@ -670,15 +725,15 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
                 _            -> return (t:fromMaybe [] (getSetParams rest))
     getSetParams [] = Nothing
 
-    getPrintfVariable list = f $ map (\x -> (x, getLiteralString x)) list
+    getPrintfVariable list = getFlagAssignedVariable "v" (SourceFrom list) $ getBsdOpts "v:" list
-      where
+    getWaitVariable   list = getFlagAssignedVariable "p" SourceInteger     $ return $ getGenericOpts list
-        f ((_, Just "-v") : (t, Just var) : _) = return (base, t, varName, varType $ SourceFrom list)
+
-            where
+    getFlagAssignedVariable str dataSource maybeFlags = do
-                (varName, varType) = case elemIndex '[' var of
+        flags <- maybeFlags
-                    Just i -> (take i var, DataArray)
+        (_, (flag, value)) <- find ((== str) . fst) flags
-                    Nothing -> (var, DataString)
+        variableName <- getLiteralStringExt (const $ return "!") value
-        f (_:rest) = f rest
+        let (baseName, index) = span (/= '[') variableName
-        f [] = fail "not found"
+        return (base, value, baseName, (if null index then DataString else DataArray) dataSource)
 
     -- mapfile has some curious syntax allowing flags plus 0..n variable names
     -- where only the first non-option one is used if any.
@@ -712,24 +767,19 @@ getModifiedVariableCommand base@(T_SimpleCommand id cmdPrefix (T_NormalWord _ (T
 
 getModifiedVariableCommand _ = []
 
-getIndexReferences s = fromMaybe [] $ do
+-- Given a NormalWord like foo or foo[$bar], get foo.
-    match <- matchRegex re s
+-- Primarily used to get references for [[ -v foo[bar] ]]
-    index <- match !!! 0
+getVariableForTestDashV :: Token -> Maybe String
-    return $ matchAllStrings variableNameRegex index
+getVariableForTestDashV t = do
+    str <- takeWhile ('[' /=) <$> getLiteralStringExt toStr t
+    guard $ isVariableName str
+    return str
   where
-    re = mkRegex "(\\[.*\\])"
+    -- foo[bar] gets parsed with [bar] as a glob, so undo that
-
+    toStr (T_Glob _ s) = return s
-prop_getOffsetReferences1 = getOffsetReferences ":bar" == ["bar"]
+    -- Turn foo[$x] into foo[\0] so that we can get the constant array name
-prop_getOffsetReferences2 = getOffsetReferences ":bar:baz" == ["bar", "baz"]
+    -- in a non-constant expression (while filtering out foo$x[$y])
-prop_getOffsetReferences3 = getOffsetReferences "[foo]:bar" == ["bar"]
+    toStr _ = return "\0"
-prop_getOffsetReferences4 = getOffsetReferences "[foo]:bar:baz" == ["bar", "baz"]
-getOffsetReferences mods = fromMaybe [] $ do
--- if mods start with [, then drop until ]
-    match <- matchRegex re mods
-    offsets <- match !!! 1
-    return $ matchAllStrings variableNameRegex offsets
-  where
-    re = mkRegex "^(\\[.+\\])? *:([^-=?+].*)"
 
 getReferencedVariables parents t =
     case t of
@@ -748,7 +798,7 @@ getReferencedVariables parents t =
         TC_Unary id _ "-v" token -> getIfReference t token
         TC_Unary id _ "-R" token -> getIfReference t token
         TC_Binary id DoubleBracket op lhs rhs ->
-            if isDereferencing op
+            if isDereferencingBinaryOp op
             then concatMap (getIfReference t) [lhs, rhs]
             else []
 
@@ -777,17 +827,16 @@ getReferencedVariables parents t =
         T_Glob _ s -> return s    -- Also when parsed as globs
         _          -> []
 
-    getIfReference context token = do
+    getIfReference context token = maybeToList $ do
-            str@(h:_) <- getLiteralStringExt literalizer token
+            str <- getVariableForTestDashV token
-            when (isDigit h) $ fail "is a number"
             return (context, token, getBracedReference str)
 
-    isDereferencing = (`elem` ["-eq", "-ne", "-lt", "-le", "-gt", "-ge"])
-
     isArithmeticAssignment t = case getPath parents t of
-        this: TA_Assignment _ "=" lhs _ :_ -> lhs == t
+        this NE.:| TA_Assignment _ "=" lhs _ :_ -> lhs == t
         _                                  -> False
 
+isDereferencingBinaryOp = (`elem` ["-eq", "-ne", "-lt", "-le", "-gt", "-ge"])
+
 dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
 
 
@@ -810,16 +859,6 @@ isConfusedGlobRegex ('*':_) = True
 isConfusedGlobRegex [x,'*'] | x `notElem` "\\." = True
 isConfusedGlobRegex _       = False
 
-isVariableStartChar x = x == '_' || isAsciiLower x || isAsciiUpper x
-isVariableChar x = isVariableStartChar x || isDigit x
-variableNameRegex = mkRegex "[_a-zA-Z][_a-zA-Z0-9]*"
-
-prop_isVariableName1 = isVariableName "_fo123"
-prop_isVariableName2 = not $ isVariableName "4"
-prop_isVariableName3 = not $ isVariableName "test: "
-isVariableName (x:r) = isVariableStartChar x && all isVariableChar r
-isVariableName _     = False
-
 getVariablesFromLiteralToken token =
     getVariablesFromLiteral (getLiteralStringDef " " token)
 
@@ -832,67 +871,6 @@ getVariablesFromLiteral string =
   where
     variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
 
--- Get the variable name from an expansion like ${var:-foo}
-prop_getBracedReference1 = getBracedReference "foo" == "foo"
-prop_getBracedReference2 = getBracedReference "#foo" == "foo"
-prop_getBracedReference3 = getBracedReference "#" == "#"
-prop_getBracedReference4 = getBracedReference "##" == "#"
-prop_getBracedReference5 = getBracedReference "#!" == "!"
-prop_getBracedReference6 = getBracedReference "!#" == "#"
-prop_getBracedReference7 = getBracedReference "!foo#?" == "foo"
-prop_getBracedReference8 = getBracedReference "foo-bar" == "foo"
-prop_getBracedReference9 = getBracedReference "foo:-bar" == "foo"
-prop_getBracedReference10= getBracedReference "foo: -1" == "foo"
-prop_getBracedReference11= getBracedReference "!os*" == ""
-prop_getBracedReference11b= getBracedReference "!os@" == ""
-prop_getBracedReference12= getBracedReference "!os?bar**" == ""
-prop_getBracedReference13= getBracedReference "foo[bar]" == "foo"
-getBracedReference s = fromMaybe s $
-    nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
-  where
-    noPrefix = dropPrefix s
-    dropPrefix (c:rest) | c `elem` "!#" = rest
-    dropPrefix cs = cs
-    takeName s = do
-        let name = takeWhile isVariableChar s
-        guard . not $ null name
-        return name
-    getSpecial (c:_) | c `elem` "*@#?-$!" = return [c]
-    getSpecial _ = fail "empty or not special"
-
-    nameExpansion ('!':next:rest) = do -- e.g. ${!foo*bar*}
-        guard $ isVariableChar next -- e.g. ${!@}
-        first <- find (not . isVariableChar) rest
-        guard $ first `elem` "*?@"
-        return ""
-    nameExpansion _ = Nothing
-
-prop_getBracedModifier1 = getBracedModifier "foo:bar:baz" == ":bar:baz"
-prop_getBracedModifier2 = getBracedModifier "!var:-foo" == ":-foo"
-prop_getBracedModifier3 = getBracedModifier "foo[bar]" == "[bar]"
-getBracedModifier s = headOrDefault "" $ do
-    let var = getBracedReference s
-    a <- dropModifier s
-    dropPrefix var a
-  where
-    dropPrefix [] t        = return t
-    dropPrefix (a:b) (c:d) | a == c = dropPrefix b d
-    dropPrefix _ _         = []
-
-    dropModifier (c:rest) | c `elem` "#!" = [rest, c:rest]
-    dropModifier x        = [x]
-
--- Useful generic functions.
-
--- Get element 0 or a default. Like `head` but safe.
-headOrDefault _ (a:_) = a
-headOrDefault def _   = def
-
---- Get element n of a list, or Nothing. Like `!!` but safe.
-(!!!) list i =
-    case drop i list of
-        []    -> Nothing
-        (r:_) -> Just r
 
 -- Run a command if the shell is in the given list
 whenShell l c = do
@@ -936,14 +914,31 @@ supportsArrays Bash = True
 supportsArrays Ksh = True
 supportsArrays _ = False
 
--- Returns true if the shell is Bash or Ksh (sorry for the name, Ksh)
+isTrueAssignmentSource c =
-isBashLike :: Parameters -> Bool
+    case c of
-isBashLike params =
+        DataString SourceChecked -> False
-    case shellType params of
+        DataString SourceDeclaration -> False
-        Bash -> True
+        DataArray SourceChecked -> False
-        Ksh -> True
+        DataArray SourceDeclaration -> False
-        Dash -> False
+        _ -> True
-        Sh -> False
+
+modifiesVariable params token name =
+    or $ map check flow
+  where
+    flow = getVariableFlow params token
+    check t =
+        case t of
+            Assignment (_, _, n, source) -> isTrueAssignmentSource source && n == name
+            _ -> False
+
+isTestCommand t =
+    case t of
+        T_Condition {} -> True
+        T_SimpleCommand {} -> t `isCommand` "test"
+        T_Redirecting _ _ t -> isTestCommand t
+        T_Annotation _ _ t -> isTestCommand t
+        T_Pipeline _ _ [t] -> isTestCommand t
+        _ -> False
 
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Checker.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2019 Vidar Holen
+    Copyright 2012-2022 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -20,10 +20,12 @@
 {-# LANGUAGE TemplateHaskell #-}
 module ShellCheck.Checker (checkScript, ShellCheck.Checker.runTests) where
 
+import ShellCheck.Analyzer
+import ShellCheck.ASTLib
 import ShellCheck.Interface
 import ShellCheck.Parser
-import ShellCheck.Analyzer
 
+import Debug.Trace -- DO NOT SUBMIT
 import Data.Either
 import Data.Functor
 import Data.List
@@ -85,7 +87,8 @@ checkScript sys spec = do
                     asCheckSourced = csCheckSourced spec,
                     asExecutionMode = Executed,
                     asTokenPositions = tokenPositions,
-                    asOptionalChecks = csOptionalChecks spec
+                    asExtendedAnalysis = csExtendedAnalysis spec,
+                    asOptionalChecks = getEnableDirectives root ++ csOptionalChecks spec
                 } where as = newAnalysisSpec root
         let analysisMessages =
                 maybe []
@@ -156,6 +159,11 @@ checkWithIncludesAndSourcePath includes mapper = getErrors
         siFindSource = mapper
     }
 
+checkWithRcIncludesAndSourcePath rc includes mapper = getErrors
+    (mockRcFile rc $ mockedSystemInterface includes) {
+        siFindSource = mapper
+    }
+
 prop_findsParseIssue = check "echo \"$12\"" == [1037]
 
 prop_commentDisablesParseIssue1 =
@@ -213,6 +221,9 @@ prop_worksWhenSourcing =
 prop_worksWhenSourcingWithDashDash =
     null $ checkWithIncludes [("lib", "bar=1")] "source -- lib; echo \"$bar\""
 
+prop_worksWhenSourcingWithDashP =
+    null $ checkWithIncludes [("lib", "bar=1")] "source -p \"$MYPATH\" lib; echo \"$bar\""
+
 prop_worksWhenDotting =
     null $ checkWithIncludes [("lib", "bar=1")] ". lib; echo \"$bar\""
 
@@ -238,6 +249,9 @@ prop_canStripPrefixAndSource2 =
 prop_canSourceDynamicWhenRedirected =
     null $ checkWithIncludes [("lib", "")] "#shellcheck source=lib\n. \"$1\""
 
+prop_canRedirectWithSpaces =
+    null $ checkWithIncludes [("my file", "")] "#shellcheck source=\"my file\"\n. \"$1\""
+
 prop_recursiveAnalysis =
     [2086] == checkRecursive [("lib", "echo $1")] "source lib"
 
@@ -301,6 +315,13 @@ prop_canDisableShebangWarning = null $ result
         csScript = "#shellcheck disable=SC2148\nfoo"
     }
 
+prop_canDisableAllWarnings = result == [2086]
+  where
+    result = checkWithSpec [] emptyCheckSpec {
+        csFilename = "file.sh",
+        csScript = "#!/bin/sh\necho $1\n#shellcheck disable=all\necho `echo $1`"
+    }
+
 prop_canDisableParseErrors = null $ result
   where
     result = checkWithSpec [] emptyCheckSpec {
@@ -384,7 +405,7 @@ prop_canEnableOptionalsWithRc = result == [2244]
 
 prop_sourcePathRedirectsName = result == [2086]
   where
-    f "dir/myscript" _ "lib" = return "foo/lib"
+    f "dir/myscript" _ _ "lib" = return "foo/lib"
     result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
         csScript = "#!/bin/bash\nsource lib",
         csFilename = "dir/myscript",
@@ -393,22 +414,154 @@ prop_sourcePathRedirectsName = result == [2086]
 
 prop_sourcePathAddsAnnotation = result == [2086]
   where
-    f "dir/myscript" ["mypath"] "lib" = return "foo/lib"
+    f "dir/myscript" _ ["mypath"] "lib" = return "foo/lib"
     result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
         csScript = "#!/bin/bash\n# shellcheck source-path=mypath\nsource lib",
         csFilename = "dir/myscript",
         csCheckSourced = True
     }
 
+prop_sourcePathWorksWithSpaces = result == [2086]
+  where
+    f "dir/myscript" _ ["my path"] "lib" = return "foo/lib"
+    result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck source-path='my path'\nsource lib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
 prop_sourcePathRedirectsDirective = result == [2086]
   where
-    f "dir/myscript" _ "lib" = return "foo/lib"
+    f "dir/myscript" _ _ "lib" = return "foo/lib"
-    f _ _ _ = return "/dev/null"
+    f _ _ _ _ = return "/dev/null"
     result = checkWithIncludesAndSourcePath [("foo/lib", "echo $1")] f emptyCheckSpec {
         csScript = "#!/bin/bash\n# shellcheck source=lib\nsource kittens",
         csFilename = "dir/myscript",
         csCheckSourced = True
     }
 
+prop_rcCanAllowExternalSources = result == [2086]
+  where
+    f "dir/myscript" (Just True) _ "mylib" = return "resolved/mylib"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=true" [("resolved/mylib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource mylib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanDenyExternalSources = result == [2086]
+  where
+    f "dir/myscript" (Just False) _ "mylib" = return "resolved/mylib"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=false" [("resolved/mylib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource mylib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanLeaveExternalSourcesUnspecified = result == [2086]
+  where
+    f "dir/myscript" Nothing _ "mylib" = return "resolved/mylib"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "" [("resolved/mylib", "echo $1")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\nsource mylib",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_fileCanDisableExternalSources = result == [2006, 2086]
+  where
+    f "dir/myscript" (Just True) _ "withExternal" = return "withExternal"
+    f "dir/myscript" (Just False) _ "withoutExternal" = return "withoutExternal"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=true" [("withExternal", "echo $1"), ("withoutExternal", "_=`foo`")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\ntrue\nsource withExternal\n# shellcheck external-sources=false\nsource withoutExternal",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_fileCannotEnableExternalSources = result == [1144]
+  where
+    f "dir/myscript" Nothing _ "foo" = return "foo"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "" [("foo", "true")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck external-sources=true\nsource foo",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_fileCannotEnableExternalSources2 = result == [1144]
+  where
+    f "dir/myscript" (Just False) _ "foo" = return "foo"
+    f a b c d = error $ show ("Unexpected", a, b, c, d)
+    result = checkWithRcIncludesAndSourcePath "external-sources=false" [("foo", "true")] f emptyCheckSpec {
+        csScript = "#!/bin/bash\n# shellcheck external-sources=true\nsource foo",
+        csFilename = "dir/myscript",
+        csCheckSourced = True
+    }
+
+prop_rcCanSuppressEarlyProblems1 = null result
+  where
+    result = checkWithRc "disable=1071" emptyCheckSpec {
+        csScript = "#!/bin/zsh\necho $1"
+    }
+
+prop_rcCanSuppressEarlyProblems2 = null result
+  where
+    result = checkWithRc "disable=1104" emptyCheckSpec {
+        csScript = "!/bin/bash\necho 'hello world'"
+    }
+
+prop_sourceWithHereDocWorks = null result
+  where
+    result = checkWithIncludes [("bar", "true\n")] "source bar << eof\nlol\neof"
+
+prop_hereDocsAreParsedWithoutTrailingLinefeed = 1044 `elem` result
+  where
+    result = check "cat << eof"
+
+prop_hereDocsWillHaveParsedIndices = null result
+  where
+    result = check "#!/bin/bash\nmy_array=(a b)\ncat <<EOF >> ./test\n $(( 1 + my_array[1] ))\nEOF"
+
+prop_rcCanSuppressDfa = null result
+  where
+    result = checkWithRc "extended-analysis=false" emptyCheckSpec {
+        csScript = "#!/bin/sh\nexit; foo;"
+    }
+
+prop_fileCanSuppressDfa = null $ traceShowId result
+  where
+    result = checkWithRc "" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=false\nexit; foo;"
+    }
+
+prop_fileWinsWhenSuppressingDfa1 = null result
+  where
+    result = checkWithRc "extended-analysis=true" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=false\nexit; foo;"
+    }
+
+prop_fileWinsWhenSuppressingDfa2 = result == [2317]
+  where
+    result = checkWithRc "extended-analysis=false" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=true\nexit; foo;"
+    }
+
+prop_flagWinsWhenSuppressingDfa1 = result == [2317]
+  where
+    result = checkWithRc "extended-analysis=false" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=false\nexit; foo;",
+        csExtendedAnalysis = Just True
+    }
+
+prop_flagWinsWhenSuppressingDfa2 = null result
+  where
+    result = checkWithRc "extended-analysis=true" emptyCheckSpec {
+        csScript = "#!/bin/sh\n# shellcheck extended-analysis=true\nexit; foo;",
+        csExtendedAnalysis = Just False
+    }
+
 return []
 runTests = $quickCheckAll

src/ShellCheck/Checks/Commands.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2019 Vidar Holen
+    Copyright 2012-2022 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -20,6 +20,7 @@
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE PatternGuards #-}
 
 -- This module contains checks that examine specific commands by name.
 module ShellCheck.Checks.Commands (checker, optionalChecks, ShellCheck.Checks.Commands.runTests) where
@@ -27,21 +28,29 @@ module ShellCheck.Checks.Commands (checker, optionalChecks, ShellCheck.Checks.Co
 import ShellCheck.AST
 import ShellCheck.ASTLib
 import ShellCheck.AnalyzerLib
+import ShellCheck.CFG
+import qualified ShellCheck.CFGAnalysis as CF
 import ShellCheck.Data
 import ShellCheck.Interface
 import ShellCheck.Parser
+import ShellCheck.Prelude
 import ShellCheck.Regex
 
 import Control.Monad
 import Control.Monad.RWS
 import Data.Char
 import Data.Functor.Identity
+import qualified Data.Graph.Inductive.Graph as G
 import Data.List
 import Data.Maybe
-import qualified Data.Map.Strict as Map
+import qualified Data.List.NonEmpty as NE
+import qualified Data.Map.Strict as M
+import qualified Data.Set as S
 import Test.QuickCheck.All (forAllProperties)
 import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
 
+import Debug.Trace -- STRIP
+
 data CommandName = Exactly String | Basename String
     deriving (Eq, Ord)
 
@@ -57,7 +66,7 @@ commandChecks :: [CommandCheck]
 commandChecks = [
     checkTr
     ,checkFindNameGlob
-    ,checkNeedlessExpr
+    ,checkExpr
     ,checkGrepRe
     ,checkTrapQuotes
     ,checkReturn
@@ -95,7 +104,14 @@ commandChecks = [
     ,checkSourceArgs
     ,checkChmodDashr
     ,checkXargsDashi
+    ,checkUnquotedEchoSpaces
+    ,checkEvalArray
     ]
+    ++ map checkArgComparison ("alias" : declaringCommands)
+    ++ map checkMaskedReturns declaringCommands
+    ++ map checkMultipleDeclaring declaringCommands
+    ++ map checkBackreferencingDeclaration declaringCommands
+
 
 optionalChecks = map fst optionalCommandChecks
 optionalCommandChecks :: [(CheckDescription, CommandCheck)]
@@ -107,7 +123,7 @@ optionalCommandChecks = [
         cdNegative = "command -v javac"
     }, checkWhich)
     ]
-optionalCheckMap = Map.fromList $ map (\(desc, check) -> (cdName desc, check)) optionalCommandChecks
+optionalCheckMap = M.fromList $ map (\(desc, check) -> (cdName desc, check)) optionalCommandChecks
 
 prop_verifyOptionalExamples = all check optionalCommandChecks
   where
@@ -131,40 +147,51 @@ prop_checkGetOptsS3 = checkGetOpts "-f -x" ["f", "x"] [] $ getOpts (True, True)
 prop_checkGetOptsS4 = checkGetOpts "-f -x" ["f"] [] $ getOpts (True, True) "f:" []
 prop_checkGetOptsS5 = checkGetOpts "-fx" [] [] $ getOpts (True, True) "fx:" []
 
+prop_checkGenericOptsS1 = checkGetOpts "-f x" ["f"] [] $ return . getGenericOpts
+prop_checkGenericOptsS2 = checkGetOpts "-abc x" ["a", "b", "c"] [] $ return . getGenericOpts
+prop_checkGenericOptsS3 = checkGetOpts "-abc -x" ["a", "b", "c", "x"] [] $ return . getGenericOpts
+prop_checkGenericOptsS4 = checkGetOpts "-x" ["x"] [] $ return . getGenericOpts
+
 -- Long options
 prop_checkGetOptsL1 = checkGetOpts "--foo=bar baz" ["foo"] ["baz"] $ getOpts (True, False) "" [("foo", True)]
 prop_checkGetOptsL2 = checkGetOpts "--foo bar baz" ["foo"] ["baz"] $ getOpts (True, False) "" [("foo", True)]
 prop_checkGetOptsL3 = checkGetOpts "--foo baz" ["foo"] ["baz"] $ getOpts (True, True) "" []
 prop_checkGetOptsL4 = checkGetOpts "--foo baz" [] [] $ getOpts (True, False) "" []
 
+prop_checkGenericOptsL1 = checkGetOpts "--foo=bar" ["foo"] [] $ return . getGenericOpts
+prop_checkGenericOptsL2 = checkGetOpts "--foo bar" ["foo"] ["bar"] $ return . getGenericOpts
+prop_checkGenericOptsL3 = checkGetOpts "-x --foo" ["x", "foo"] [] $ return . getGenericOpts
+
 -- Know when to terminate
 prop_checkGetOptsT1 = checkGetOpts "-a x -b" ["a", "b"] ["x"] $ getOpts (True, True) "ab" []
 prop_checkGetOptsT2 = checkGetOpts "-a x -b" ["a"] ["x","-b"] $ getOpts (False, True) "ab" []
 prop_checkGetOptsT3 = checkGetOpts "-a -- -b" ["a"] ["-b"] $ getOpts (True, True) "ab" []
 prop_checkGetOptsT4 = checkGetOpts "-a -- -b" ["a", "b"] [] $ getOpts (True, True) "a:b" []
 
+prop_checkGenericOptsT1 = checkGetOpts "-x -- -y" ["x"] ["-y"] $ return . getGenericOpts
+prop_checkGenericOptsT2 = checkGetOpts "-xy --" ["x", "y"] [] $ return . getGenericOpts
 
-buildCommandMap :: [CommandCheck] -> Map.Map CommandName (Token -> Analysis)
+
-buildCommandMap = foldl' addCheck Map.empty
+buildCommandMap :: [CommandCheck] -> M.Map CommandName (Token -> Analysis)
+buildCommandMap = foldl' addCheck M.empty
   where
     addCheck map (CommandCheck name function) =
-        Map.insertWith composeAnalyzers name function map
+        M.insertWith composeAnalyzers name function map
 
 
-checkCommand :: Map.Map CommandName (Token -> Analysis) -> Token -> Analysis
+checkCommand :: M.Map CommandName (Token -> Analysis) -> Token -> Analysis
 checkCommand map t@(T_SimpleCommand id cmdPrefix (cmd:rest)) = sequence_ $ do
     name <- getLiteralString cmd
     return $
-        if '/' `elem` name
+        if | '/' `elem` name ->
-        then
+               M.findWithDefault nullCheck (Basename $ basename name) map t
-            Map.findWithDefault nullCheck (Basename $ basename name) map t
+           | name == "builtin", (h:_) <- rest ->
-        else if name == "builtin" && not (null rest) then
+               let t' = T_SimpleCommand id cmdPrefix rest
-            let t' = T_SimpleCommand id cmdPrefix rest
+                   selectedBuiltin = onlyLiteralString h
-                selectedBuiltin = fromMaybe "" $ getLiteralString . head $ rest
+               in M.findWithDefault nullCheck (Exactly selectedBuiltin) map t'
-            in Map.findWithDefault nullCheck (Exactly selectedBuiltin) map t'
+           | otherwise -> do
-        else do
+               M.findWithDefault nullCheck (Exactly name) map t
-            Map.findWithDefault nullCheck (Exactly name) map t
+               M.findWithDefault nullCheck (Basename name) map t
-            Map.findWithDefault nullCheck (Basename name) map t
 
   where
     basename = reverse . takeWhile (/= '/') . reverse
@@ -186,22 +213,22 @@ checker spec params = getChecker $ commandChecks ++ optionals
     optionals =
         if "all" `elem` keys
         then map snd optionalCommandChecks
-        else mapMaybe (\x -> Map.lookup x optionalCheckMap) keys
+        else mapMaybe (\x -> M.lookup x optionalCheckMap) keys
 
 prop_checkTr1 = verify checkTr "tr [a-f] [A-F]"
 prop_checkTr2 = verify checkTr "tr 'a-z' 'A-Z'"
-prop_checkTr2a= verify checkTr "tr '[a-z]' '[A-Z]'"
+prop_checkTr2a = verify checkTr "tr '[a-z]' '[A-Z]'"
 prop_checkTr3 = verifyNot checkTr "tr -d '[:lower:]'"
-prop_checkTr3a= verifyNot checkTr "tr -d '[:upper:]'"
+prop_checkTr3a = verifyNot checkTr "tr -d '[:upper:]'"
-prop_checkTr3b= verifyNot checkTr "tr -d '|/_[:upper:]'"
+prop_checkTr3b = verifyNot checkTr "tr -d '|/_[:upper:]'"
 prop_checkTr4 = verifyNot checkTr "ls [a-z]"
 prop_checkTr5 = verify checkTr "tr foo bar"
 prop_checkTr6 = verify checkTr "tr 'hello' 'world'"
 prop_checkTr8 = verifyNot checkTr "tr aeiou _____"
 prop_checkTr9 = verifyNot checkTr "a-z n-za-m"
-prop_checkTr10= verifyNot checkTr "tr --squeeze-repeats rl lr"
+prop_checkTr10 = verifyNot checkTr "tr --squeeze-repeats rl lr"
-prop_checkTr11= verifyNot checkTr "tr abc '[d*]'"
+prop_checkTr11 = verifyNot checkTr "tr abc '[d*]'"
-prop_checkTr12= verifyNot checkTr "tr '[=e=]' 'e'"
+prop_checkTr12 = verifyNot checkTr "tr '[=e=]' 'e'"
 checkTr = CommandCheck (Basename "tr") (mapM_ f . arguments)
   where
     f w | isGlob w = -- The user will go [ab] -> '[ab]' -> 'ab'. Fixme?
@@ -235,19 +262,74 @@ checkFindNameGlob = CommandCheck (Basename "find") (f . arguments)  where
         acc b
 
 
-prop_checkNeedlessExpr = verify checkNeedlessExpr "foo=$(expr 3 + 2)"
+prop_checkExpr = verify checkExpr "foo=$(expr 3 + 2)"
-prop_checkNeedlessExpr2 = verify checkNeedlessExpr "foo=`echo \\`expr 3 + 2\\``"
+prop_checkExpr2 = verify checkExpr "foo=`echo \\`expr 3 + 2\\``"
-prop_checkNeedlessExpr3 = verifyNot checkNeedlessExpr "foo=$(expr foo : regex)"
+prop_checkExpr3 = verifyNot checkExpr "foo=$(expr foo : regex)"
-prop_checkNeedlessExpr4 = verifyNot checkNeedlessExpr "foo=$(expr foo \\< regex)"
+prop_checkExpr4 = verifyNot checkExpr "foo=$(expr foo \\< regex)"
-checkNeedlessExpr = CommandCheck (Basename "expr") f where
+prop_checkExpr5 = verify checkExpr "# shellcheck disable=SC2003\nexpr match foo bar"
-    f t =
+prop_checkExpr6 = verify checkExpr "# shellcheck disable=SC2003\nexpr foo : fo*"
+prop_checkExpr7 = verify checkExpr "# shellcheck disable=SC2003\nexpr 5 -3"
+prop_checkExpr8 = verifyNot checkExpr "# shellcheck disable=SC2003\nexpr \"$@\""
+prop_checkExpr9 = verifyNot checkExpr "# shellcheck disable=SC2003\nexpr 5 $rest"
+prop_checkExpr10 = verify checkExpr "# shellcheck disable=SC2003\nexpr length \"$var\""
+prop_checkExpr11 = verify checkExpr "# shellcheck disable=SC2003\nexpr foo > bar"
+prop_checkExpr12 = verify checkExpr "# shellcheck disable=SC2003\nexpr 1 | 2"
+prop_checkExpr13 = verify checkExpr "# shellcheck disable=SC2003\nexpr 1 * 2"
+prop_checkExpr14 = verify checkExpr "# shellcheck disable=SC2003\nexpr \"$x\" >=  \"$y\""
+
+checkExpr = CommandCheck (Basename "expr") f where
+    f t = do
         when (all (`notElem` exceptions) (words $ arguments t)) $
             style (getId $ getCommandTokenOrThis t) 2003
                 "expr is antiquated. Consider rewriting this using $((..)), ${} or [[ ]]."
+
+        case arguments t of
+            [lhs, op, rhs] -> do
+                checkOp lhs
+                case getWordParts op of
+                    [T_Glob _ "*"] ->
+                        err (getId op) 2304
+                            "* must be escaped to multiply: \\*. Modern $((x * y)) avoids this issue."
+                    [T_Literal _ ":"] | isGlob rhs ->
+                        warn (getId rhs) 2305
+                            "Quote regex argument to expr to avoid it expanding as a glob."
+                    _ -> return ()
+
+            [single] | not (willSplit single) ->
+                warn (getId single) 2307
+                    "'expr' expects 3+ arguments but sees 1. Make sure each operator/operand is a separate argument, and escape <>&|."
+
+            [first, second] |
+                onlyLiteralString first /= "length"
+                  && not (willSplit first || willSplit second) -> do
+                    checkOp first
+                    warn (getId t) 2307
+                        "'expr' expects 3+ arguments, but sees 2. Make sure each operator/operand is a separate argument, and escape <>&|."
+
+            (first:rest) -> do
+                checkOp first
+                forM_ rest $ \t ->
+                    -- We already find 95%+ of multiplication and regex earlier, so don't bother classifying this further.
+                    when (isGlob t) $ warn (getId t) 2306 "Escape glob characters in arguments to expr to avoid pathname expansion."
+
+            _ -> return ()
+
     -- These operators are hard to replicate in POSIX
-    exceptions = [ ":", "<", ">", "<=", ">=" ]
+    exceptions = [ ":", "<", ">", "<=", ">=",
+        -- We can offer better suggestions for these
+        "match", "length", "substr", "index"]
     words = mapMaybe getLiteralString
 
+    checkOp side =
+        case getLiteralString side of
+            Just "match" -> msg "'expr match' has unspecified results. Prefer 'expr str : regex'."
+            Just "length" -> msg "'expr length' has unspecified results. Prefer ${#var}."
+            Just "substr" -> msg "'expr substr' has unspecified results. Prefer 'cut' or ${var#???}."
+            Just "index" -> msg "'expr index' has unspecified results. Prefer x=${var%%[chars]*}; $((${#x}+1))."
+            _ -> return ()
+      where
+        msg = info (getId side) 2308
+
 
 prop_checkGrepRe1 = verify checkGrepRe "cat foo | grep *.mp3"
 prop_checkGrepRe2 = verify checkGrepRe "grep -Ev cow*test *.mp3"
@@ -258,20 +340,20 @@ prop_checkGrepRe6 = verifyNot checkGrepRe "grep foo \\*.mp3"
 prop_checkGrepRe7 = verify checkGrepRe "grep *foo* file"
 prop_checkGrepRe8 = verify checkGrepRe "ls | grep foo*.jpg"
 prop_checkGrepRe9 = verifyNot checkGrepRe "grep '[0-9]*' file"
-prop_checkGrepRe10= verifyNot checkGrepRe "grep '^aa*' file"
+prop_checkGrepRe10 = verifyNot checkGrepRe "grep '^aa*' file"
-prop_checkGrepRe11= verifyNot checkGrepRe "grep --include=*.png foo"
+prop_checkGrepRe11 = verifyNot checkGrepRe "grep --include=*.png foo"
-prop_checkGrepRe12= verifyNot checkGrepRe "grep -F 'Foo*' file"
+prop_checkGrepRe12 = verifyNot checkGrepRe "grep -F 'Foo*' file"
-prop_checkGrepRe13= verifyNot checkGrepRe "grep -- -foo bar*"
+prop_checkGrepRe13 = verifyNot checkGrepRe "grep -- -foo bar*"
-prop_checkGrepRe14= verifyNot checkGrepRe "grep -e -foo bar*"
+prop_checkGrepRe14 = verifyNot checkGrepRe "grep -e -foo bar*"
-prop_checkGrepRe15= verifyNot checkGrepRe "grep --regex -foo bar*"
+prop_checkGrepRe15 = verifyNot checkGrepRe "grep --regex -foo bar*"
-prop_checkGrepRe16= verifyNot checkGrepRe "grep --include 'Foo*' file"
+prop_checkGrepRe16 = verifyNot checkGrepRe "grep --include 'Foo*' file"
-prop_checkGrepRe17= verifyNot checkGrepRe "grep --exclude 'Foo*' file"
+prop_checkGrepRe17 = verifyNot checkGrepRe "grep --exclude 'Foo*' file"
-prop_checkGrepRe18= verifyNot checkGrepRe "grep --exclude-dir 'Foo*' file"
+prop_checkGrepRe18 = verifyNot checkGrepRe "grep --exclude-dir 'Foo*' file"
-prop_checkGrepRe19= verify checkGrepRe "grep -- 'Foo*' file"
+prop_checkGrepRe19 = verify checkGrepRe "grep -- 'Foo*' file"
-prop_checkGrepRe20= verifyNot checkGrepRe "grep --fixed-strings 'Foo*' file"
+prop_checkGrepRe20 = verifyNot checkGrepRe "grep --fixed-strings 'Foo*' file"
-prop_checkGrepRe21= verifyNot checkGrepRe "grep -o 'x*' file"
+prop_checkGrepRe21 = verifyNot checkGrepRe "grep -o 'x*' file"
-prop_checkGrepRe22= verifyNot checkGrepRe "grep --only-matching 'x*' file"
+prop_checkGrepRe22 = verifyNot checkGrepRe "grep --only-matching 'x*' file"
-prop_checkGrepRe23= verifyNot checkGrepRe "grep '.*' file"
+prop_checkGrepRe23 = verifyNot checkGrepRe "grep '.*' file"
 
 checkGrepRe = CommandCheck (Basename "grep") check where
     check cmd = f cmd (arguments cmd)
@@ -319,7 +401,7 @@ checkGrepRe = CommandCheck (Basename "grep") check where
 
 
 prop_checkTrapQuotes1 = verify checkTrapQuotes "trap \"echo $num\" INT"
-prop_checkTrapQuotes1a= verify checkTrapQuotes "trap \"echo `ls`\" INT"
+prop_checkTrapQuotes1a = verify checkTrapQuotes "trap \"echo `ls`\" INT"
 prop_checkTrapQuotes2 = verifyNot checkTrapQuotes "trap 'echo $num' INT"
 prop_checkTrapQuotes3 = verify checkTrapQuotes "trap \"echo $((1+num))\" EXIT DEBUG"
 checkTrapQuotes = CommandCheck (Exactly "trap") (f . arguments) where
@@ -400,9 +482,16 @@ prop_checkUnusedEchoEscapes2 = verifyNot checkUnusedEchoEscapes "echo -e 'foi\\n
 prop_checkUnusedEchoEscapes3 = verify checkUnusedEchoEscapes "echo \"n:\\t42\""
 prop_checkUnusedEchoEscapes4 = verifyNot checkUnusedEchoEscapes "echo lol"
 prop_checkUnusedEchoEscapes5 = verifyNot checkUnusedEchoEscapes "echo -n -e '\n'"
+prop_checkUnusedEchoEscapes6 = verify checkUnusedEchoEscapes "echo '\\506'"
+prop_checkUnusedEchoEscapes7 = verify checkUnusedEchoEscapes "echo '\\5a'"
+prop_checkUnusedEchoEscapes8 = verifyNot checkUnusedEchoEscapes "echo '\\8a'"
+prop_checkUnusedEchoEscapes9 = verifyNot checkUnusedEchoEscapes "echo '\\d5a'"
+prop_checkUnusedEchoEscapes10 = verify checkUnusedEchoEscapes "echo '\\x4a'"
+prop_checkUnusedEchoEscapes11 = verify checkUnusedEchoEscapes "echo '\\xat'"
+prop_checkUnusedEchoEscapes12 = verifyNot checkUnusedEchoEscapes "echo '\\xth'"
 checkUnusedEchoEscapes = CommandCheck (Basename "echo") f
   where
-    hasEscapes = mkRegex "\\\\[rnt]"
+    hasEscapes = mkRegex "\\\\([rntabefv\\']|[0-7]{1,3}|x([0-9]|[A-F]|[a-f]){1,2})"
     f cmd =
         whenShell [Sh, Bash, Ksh] $
             unless (cmd `hasFlag` "e") $
@@ -576,19 +665,19 @@ prop_checkPrintfVar6 = verify checkPrintfVar "printf foo bar baz"
 prop_checkPrintfVar7 = verify checkPrintfVar "printf -- foo bar baz"
 prop_checkPrintfVar8 = verifyNot checkPrintfVar "printf '%s %s %s' \"${var[@]}\""
 prop_checkPrintfVar9 = verifyNot checkPrintfVar "printf '%s %s %s\\n' *.png"
-prop_checkPrintfVar10= verifyNot checkPrintfVar "printf '%s %s %s' foo bar baz"
+prop_checkPrintfVar10 = verifyNot checkPrintfVar "printf '%s %s %s' foo bar baz"
-prop_checkPrintfVar11= verifyNot checkPrintfVar "printf '%(%s%s)T' -1"
+prop_checkPrintfVar11 = verifyNot checkPrintfVar "printf '%(%s%s)T' -1"
-prop_checkPrintfVar12= verify checkPrintfVar "printf '%s %s\\n' 1 2 3"
+prop_checkPrintfVar12 = verify checkPrintfVar "printf '%s %s\\n' 1 2 3"
-prop_checkPrintfVar13= verifyNot checkPrintfVar "printf '%s %s\\n' 1 2 3 4"
+prop_checkPrintfVar13 = verifyNot checkPrintfVar "printf '%s %s\\n' 1 2 3 4"
-prop_checkPrintfVar14= verify checkPrintfVar "printf '%*s\\n' 1"
+prop_checkPrintfVar14 = verify checkPrintfVar "printf '%*s\\n' 1"
-prop_checkPrintfVar15= verifyNot checkPrintfVar "printf '%*s\\n' 1 2"
+prop_checkPrintfVar15 = verifyNot checkPrintfVar "printf '%*s\\n' 1 2"
-prop_checkPrintfVar16= verifyNot checkPrintfVar "printf $'string'"
+prop_checkPrintfVar16 = verifyNot checkPrintfVar "printf $'string'"
-prop_checkPrintfVar17= verify checkPrintfVar "printf '%-*s\\n' 1"
+prop_checkPrintfVar17 = verify checkPrintfVar "printf '%-*s\\n' 1"
-prop_checkPrintfVar18= verifyNot checkPrintfVar "printf '%-*s\\n' 1 2"
+prop_checkPrintfVar18 = verifyNot checkPrintfVar "printf '%-*s\\n' 1 2"
-prop_checkPrintfVar19= verifyNot checkPrintfVar "printf '%(%s)T'"
+prop_checkPrintfVar19 = verifyNot checkPrintfVar "printf '%(%s)T'"
-prop_checkPrintfVar20= verifyNot checkPrintfVar "printf '%d %(%s)T' 42"
+prop_checkPrintfVar20 = verifyNot checkPrintfVar "printf '%d %(%s)T' 42"
-prop_checkPrintfVar21= verify checkPrintfVar "printf '%d %(%s)T'"
+prop_checkPrintfVar21 = verify checkPrintfVar "printf '%d %(%s)T'"
-prop_checkPrintfVar22= verify checkPrintfVar "printf '%s\n%s' foo"
+prop_checkPrintfVar22 = verify checkPrintfVar "printf '%s\n%s' foo"
 
 checkPrintfVar = CommandCheck (Exactly "printf") (f . arguments) where
     f (doubledash:rest) | getLiteralString doubledash == Just "--" = f rest
@@ -602,6 +691,7 @@ checkPrintfVar = CommandCheck (Exactly "printf") (f . arguments) where
             let formats = getPrintfFormats string
             let formatCount = length formats
             let argCount = length more
+            let pluraliseIfMany word n = if n > 1 then word ++ "s" else word
 
             return $ if
                 | argCount == 0 && formatCount == 0 ->
@@ -617,7 +707,8 @@ checkPrintfVar = CommandCheck (Exactly "printf") (f . arguments) where
                     return () -- Great: a suitable number of arguments
                 | otherwise ->
                     warn (getId format) 2183 $
-                        "This format string has " ++ show formatCount ++ " variables, but is passed " ++ show argCount ++ " arguments."
+                        "This format string has " ++ show formatCount ++ " " ++ pluraliseIfMany "variable" formatCount ++
+                        ", but is passed " ++ show argCount ++ pluraliseIfMany " argument" argCount ++ "."
 
         unless ('%' `elem` concat (oversimplify format) || isLiteral format) $
           info (getId format) 2059
@@ -634,6 +725,9 @@ prop_checkGetPrintfFormats4 = getPrintfFormats "%d%%%(%s)T" == "dT"
 prop_checkGetPrintfFormats5 = getPrintfFormats "%bPassed: %d, %bFailed: %d%b, Skipped: %d, %bErrored: %d%b\\n" == "bdbdbdbdb"
 prop_checkGetPrintfFormats6 = getPrintfFormats "%s%s" == "ss"
 prop_checkGetPrintfFormats7 = getPrintfFormats "%s\n%s" == "ss"
+prop_checkGetPrintfFormats8 = getPrintfFormats "%ld" == "d"
+prop_checkGetPrintfFormats9 = getPrintfFormats "%lld" == "d"
+prop_checkGetPrintfFormats10 = getPrintfFormats "%Q" == "Q"
 getPrintfFormats = getFormats
   where
     -- Get the arguments in the string as a string of type characters,
@@ -652,18 +746,18 @@ getPrintfFormats = getFormats
 
     regexBasedGetFormats rest =
         case matchRegex re rest of
-            Just [width, precision, typ, rest, _] ->
+            Just [width, precision, len, typ, rest, _] ->
                 (if width == "*" then "*" else "") ++
                 (if precision == "*" then "*" else "") ++
                 typ ++ getFormats rest
             Nothing -> take 1 rest ++ getFormats rest
       where
         -- constructed based on specifications in "man printf"
-        re = mkRegex "#?-?\\+? ?0?(\\*|\\d*)\\.?(\\d*|\\*)([diouxXfFeEgGaAcsbq])((\n|.)*)"
+        re = mkRegex "^#?-?\\+? ?0?(\\*|\\d*)\\.?(\\d*|\\*)(hh|h|l|ll|q|L|j|z|Z|t)?([diouxXfFeEgGaAcsbqQSC])((\n|.)*)"
-        --            \____ _____/\___ ____/   \____ ____/\_________ _________/ \______ /
+        --             \____ _____/\___ ____/   \____ ____/\__________ ___________/\___________ ___________/\___ ___/
-        --                 V          V             V               V               V
+        --                  V          V             V                V                        V                V
-        --               flags    field width  precision   format character        rest
+        --                flags    field width  precision        length modifier      format character         rest
-        -- field width and precision can be specified with a '*' instead of a digit,
+        -- field width and precision can be specified with an '*' instead of a digit,
         -- in which case printf will accept one more argument for each '*' used
 
 
@@ -718,6 +812,7 @@ prop_checkReadExpansions5 = verify checkReadExpansions "read \"$var\""
 prop_checkReadExpansions6 = verify checkReadExpansions "read -a $var"
 prop_checkReadExpansions7 = verifyNot checkReadExpansions "read $1"
 prop_checkReadExpansions8 = verifyNot checkReadExpansions "read ${var?}"
+prop_checkReadExpansions9 = verify checkReadExpansions "read arr[val]"
 checkReadExpansions = CommandCheck (Exactly "read") check
   where
     options = getGnuOpts flagsForRead
@@ -725,13 +820,26 @@ checkReadExpansions = CommandCheck (Exactly "read") check
         opts <- options $ arguments cmd
         return [y | (x,(_, y)) <- opts, null x || x == "a"]
 
-    check cmd = mapM_ warning $ getVars cmd
+    check cmd = do
-    warning t = sequence_ $ do
+        mapM_ dollarWarning $ getVars cmd
+        mapM_ arrayWarning $ arguments cmd
+
+    dollarWarning t = sequence_ $ do
         name <- getSingleUnmodifiedBracedString t
         guard $ isVariableName name   -- e.g. not $1
         return . warn (getId t) 2229 $
             "This does not read '" ++ name ++ "'. Remove $/${} for that, or use ${var?} to quiet."
 
+    arrayWarning word =
+        when (any isUnquotedBracket $ getWordParts word) $
+            warn (getId word) 2313 $
+                "Quote array indices to avoid them expanding as globs."
+
+    isUnquotedBracket t =
+        case t of
+            T_Glob _ ('[':_) -> True
+            _ -> False
+
 -- Return the single variable expansion that makes up this word, if any.
 -- e.g. $foo -> $foo, "$foo"'' -> $foo , "hello $name" -> Nothing
 getSingleUnmodifiedBracedString :: Token -> Maybe String
@@ -771,6 +879,9 @@ checkAliasesExpandEarly = CommandCheck (Exactly "alias") (f . arguments)
 
 prop_checkUnsetGlobs1 = verify checkUnsetGlobs "unset foo[1]"
 prop_checkUnsetGlobs2 = verifyNot checkUnsetGlobs "unset foo"
+prop_checkUnsetGlobs3 = verify checkUnsetGlobs "unset foo[$i]"
+prop_checkUnsetGlobs4 = verify checkUnsetGlobs "unset foo[x${i}y]"
+prop_checkUnsetGlobs5 = verifyNot checkUnsetGlobs "unset foo]["
 checkUnsetGlobs = CommandCheck (Exactly "unset") (mapM_ check . arguments)
   where
     check arg =
@@ -823,7 +934,7 @@ prop_checkTimedCommand2 = verify checkTimedCommand "#!/bin/dash\ntime ( foo; bar
 prop_checkTimedCommand3 = verifyNot checkTimedCommand "#!/bin/sh\ntime sleep 1"
 checkTimedCommand = CommandCheck (Exactly "time") f where
     f (T_SimpleCommand _ _ (c:args@(_:_))) =
-        whenShell [Sh, Dash] $ do
+        whenShell [Sh, Dash, BusyboxSh] $ do
             let cmd = last args -- "time" is parsed with a command as argument
             when (isPiped cmd) $
                 warn (getId c) 2176 "'time' is undefined for pipelines. time single stage or bash -c instead."
@@ -847,11 +958,27 @@ checkTimedCommand = CommandCheck (Exactly "time") f where
 prop_checkLocalScope1 = verify checkLocalScope "local foo=3"
 prop_checkLocalScope2 = verifyNot checkLocalScope "f() { local foo=3; }"
 checkLocalScope = CommandCheck (Exactly "local") $ \t ->
-    whenShell [Bash, Dash] $ do -- Ksh allows it, Sh doesn't support local
+    whenShell [Bash, Dash, BusyboxSh] $ do -- Ksh allows it, Sh doesn't support local
         path <- getPathM t
         unless (any isFunctionLike path) $
             err (getId $ getCommandTokenOrThis t) 2168 "'local' is only valid in functions."
 
+prop_checkMultipleDeclaring1 = verify (checkMultipleDeclaring "local") "q() { local readonly var=1; }"
+prop_checkMultipleDeclaring2 = verifyNot (checkMultipleDeclaring "local") "q() { local var=1; }"
+prop_checkMultipleDeclaring3 = verify (checkMultipleDeclaring "readonly") "readonly local foo=5"
+prop_checkMultipleDeclaring4 = verify (checkMultipleDeclaring "export") "export readonly foo=5"
+prop_checkMultipleDeclaring5 = verifyNot (checkMultipleDeclaring "local") "f() { local -r foo=5; }"
+prop_checkMultipleDeclaring6 = verifyNot (checkMultipleDeclaring "declare") "declare -rx foo=5"
+prop_checkMultipleDeclaring7 = verifyNot (checkMultipleDeclaring "readonly") "readonly 'local' foo=5"
+checkMultipleDeclaring cmd = CommandCheck (Exactly cmd) (mapM_ check . arguments)
+  where
+    check t = sequence_ $ do
+        lit <- getUnquotedLiteral t
+        guard $ lit `elem` declaringCommands
+        return $ err (getId $ getCommandTokenOrThis t) 2316 $
+                 "This applies " ++ cmd ++ " to the variable named " ++ lit ++
+                 ", which is probably not what you want. Use a separate command or the appropriate `declare` options instead."
+
 prop_checkDeprecatedTempfile1 = verify checkDeprecatedTempfile "var=$(tempfile)"
 prop_checkDeprecatedTempfile2 = verifyNot checkDeprecatedTempfile "tempfile=$(mktemp)"
 checkDeprecatedTempfile = CommandCheck (Basename "tempfile") $
@@ -870,34 +997,48 @@ prop_checkWhileGetoptsCase2 = verify checkWhileGetoptsCase "while getopts 'a:' x
 prop_checkWhileGetoptsCase3 = verifyNot checkWhileGetoptsCase "while getopts 'a:b' x; do case $x in a) foo;; b) bar;; *) :;esac; done"
 prop_checkWhileGetoptsCase4 = verifyNot checkWhileGetoptsCase "while getopts 'a:123' x; do case $x in a) foo;; [0-9]) bar;; esac; done"
 prop_checkWhileGetoptsCase5 = verifyNot checkWhileGetoptsCase "while getopts 'a:' x; do case $x in a) foo;; \\?) bar;; *) baz;; esac; done"
+prop_checkWhileGetoptsCase6 = verifyNot checkWhileGetoptsCase "while getopts 'a:b' x; do case $y in a) foo;; esac; done"
+prop_checkWhileGetoptsCase7 = verifyNot checkWhileGetoptsCase "while getopts 'a:b' x; do case x$x in xa) foo;; xb) foo;; esac; done"
+prop_checkWhileGetoptsCase8 = verifyNot checkWhileGetoptsCase "while getopts 'a:b' x; do x=a; case $x in a) foo;; esac; done"
 checkWhileGetoptsCase = CommandCheck (Exactly "getopts") f
   where
     f :: Token -> Analysis
-    f t@(T_SimpleCommand _ _ (cmd:arg1:_))  = do
+    f t@(T_SimpleCommand _ _ (cmd:arg1:name:_))  = do
         path <- getPathM t
+        params <- ask
         sequence_ $ do
             options <- getLiteralString arg1
-            (T_WhileExpression _ _ body) <- findFirst whileLoop path
+            getoptsVar <- getLiteralString name
-            caseCmd <- mapMaybe findCase body !!! 0
+            (T_WhileExpression _ _ body) <- findFirst whileLoop (NE.toList path)
-            return $ check (getId arg1) (map (:[]) $ filter (/= ':') options) caseCmd
+            T_CaseExpression id var list <- mapMaybe findCase body !!! 0
+
+            -- Make sure getopts name and case variable matches
+            [T_DollarBraced _ _ bracedWord] <- return $ getWordParts var
+            [T_Literal _ caseVar] <- return $ getWordParts bracedWord
+            guard $ caseVar == getoptsVar
+
+            -- Make sure the variable isn't modified
+            guard . not $ modifiesVariable params (T_BraceGroup (Id 0) body) getoptsVar
+
+            return $ check (getId arg1) (map (:[]) $ filter (/= ':') options) id list
     f _ = return ()
 
-    check :: Id -> [String] -> Token -> Analysis
+    check :: Id -> [String] -> Id -> [(CaseType, [Token], [Token])] -> Analysis
-    check optId opts (T_CaseExpression id _ list) = do
+    check optId opts id list = do
-            unless (Nothing `Map.member` handledMap) $ do
+            unless (Nothing `M.member` handledMap) $ do
-                mapM_ (warnUnhandled optId id) $ catMaybes $ Map.keys notHandled
+                mapM_ (warnUnhandled optId id) $ catMaybes $ M.keys notHandled
 
-                unless (any (`Map.member` handledMap) [Just "*",Just "?"]) $
+                unless (any (`M.member` handledMap) [Just "*",Just "?"]) $
                     warn id 2220 "Invalid flags are not handled. Add a *) case."
 
-            mapM_ warnRedundant $ Map.toList notRequested
+            mapM_ warnRedundant $ M.toList notRequested
 
         where
-            handledMap = Map.fromList (concatMap getHandledStrings list)
+            handledMap = M.fromList (concatMap getHandledStrings list)
-            requestedMap = Map.fromList $ map (\x -> (Just x, ())) opts
+            requestedMap = M.fromList $ map (\x -> (Just x, ())) opts
 
-            notHandled = Map.difference requestedMap handledMap
+            notHandled = M.difference requestedMap handledMap
-            notRequested = Map.difference handledMap requestedMap
+            notRequested = M.difference handledMap requestedMap
 
     warnUnhandled optId caseId str =
         warn caseId 2213 $ "getopts specified -" ++ (e4m str) ++ ", but it's not handled by this 'case'."
@@ -941,10 +1082,10 @@ prop_checkCatastrophicRm4 = verify checkCatastrophicRm "rm -fr /home/$(whoami)/*
 prop_checkCatastrophicRm5 = verifyNot checkCatastrophicRm "rm -r /home/${USER:-thing}/*"
 prop_checkCatastrophicRm6 = verify checkCatastrophicRm "rm --recursive /etc/*$config*"
 prop_checkCatastrophicRm8 = verify checkCatastrophicRm "rm -rf /home"
-prop_checkCatastrophicRm10= verifyNot checkCatastrophicRm "rm -r \"${DIR}\"/{.gitignore,.gitattributes,ci}"
+prop_checkCatastrophicRm10 = verifyNot checkCatastrophicRm "rm -r \"${DIR}\"/{.gitignore,.gitattributes,ci}"
-prop_checkCatastrophicRm11= verify checkCatastrophicRm "rm -r /{bin,sbin}/$exec"
+prop_checkCatastrophicRm11 = verify checkCatastrophicRm "rm -r /{bin,sbin}/$exec"
-prop_checkCatastrophicRm12= verify checkCatastrophicRm "rm -r /{{usr,},{bin,sbin}}/$exec"
+prop_checkCatastrophicRm12 = verify checkCatastrophicRm "rm -r /{{usr,},{bin,sbin}}/$exec"
-prop_checkCatastrophicRm13= verifyNot checkCatastrophicRm "rm -r /{{a,b},{c,d}}/$exec"
+prop_checkCatastrophicRm13 = verifyNot checkCatastrophicRm "rm -r /{{a,b},{c,d}}/$exec"
 prop_checkCatastrophicRmA = verify checkCatastrophicRm "rm -rf /usr /lib/nvidia-current/xorg/xorg"
 prop_checkCatastrophicRmB = verify checkCatastrophicRm "rm -rf \"$STEAMROOT/\"*"
 checkCatastrophicRm = CommandCheck (Basename "rm") $ \t ->
@@ -1056,7 +1197,7 @@ checkFindRedirections = CommandCheck (Basename "find") f
 
 prop_checkWhich = verify checkWhich "which '.+'"
 checkWhich = CommandCheck (Basename "which") $
-    \t -> info (getId $ getCommandTokenOrThis t) 2230 "which is non-standard. Use builtin 'command -v' instead."
+    \t -> info (getId $ getCommandTokenOrThis t) 2230 "'which' is non-standard. Use builtin 'command -v' instead."
 
 prop_checkSudoRedirect1 = verify checkSudoRedirect "sudo echo 3 > /proc/file"
 prop_checkSudoRedirect2 = verify checkSudoRedirect "sudo cmd < input"
@@ -1099,12 +1240,11 @@ checkSudoArgs = CommandCheck (Basename "sudo") f
   where
     f t = sequence_ $ do
         opts <- parseOpts $ arguments t
-        let nonFlags = [x | ("",(x, _)) <- opts]
+        (_,(commandArg, _)) <- find (null . fst) opts
-        commandArg <- nonFlags !!! 0
         command <- getLiteralString commandArg
         guard $ command `elem` builtins
         return $ warn (getId t) 2232 $ "Can't use sudo with builtins like " ++ command ++ ". Did you want sudo sh -c .. instead?"
-    builtins = [ "cd", "eval", "export", "history", "read", "source", "wait" ]
+    builtins = [ "cd", "command", "declare", "eval", "exec", "exit", "export", "hash", "history", "local", "popd", "pushd", "read", "readonly", "return", "set", "source", "trap", "type", "typeset", "ulimit", "umask", "unset", "wait" ]
     -- This mess is why ShellCheck prefers not to know.
     parseOpts = getBsdOpts "vAknSbEHPa:g:h:p:u:c:T:r:"
 
@@ -1143,5 +1283,193 @@ checkXargsDashi = CommandCheck (Basename "xargs") f
         return $ info (getId option) 2267 "GNU xargs -i is deprecated in favor of -I{}"
     parseOpts = getBsdOpts "0oprtxadR:S:J:L:l:n:P:s:e:E:i:I:"
 
+
+prop_checkArgComparison1 = verify (checkArgComparison "declare") "declare a = b"
+prop_checkArgComparison2 = verify (checkArgComparison "declare") "declare a =b"
+prop_checkArgComparison3 = verifyNot (checkArgComparison "declare") "declare a=b"
+prop_checkArgComparison4 = verify (checkArgComparison "export") "export a +=b"
+prop_checkArgComparison7 = verifyNot (checkArgComparison "declare") "declare -a +i foo"
+prop_checkArgComparison8 = verify (checkArgComparison "let") "let x = 0"
+prop_checkArgComparison9 = verify (checkArgComparison "alias") "alias x =0"
+-- This mirrors checkSecondArgIsComparison but for arguments to local/readonly/declare/export
+checkArgComparison cmd = CommandCheck (Exactly cmd) wordsWithEqual
+  where
+    wordsWithEqual t = mapM_ check $ arguments t
+    check arg = do
+      sequence_ $ do
+        str <- getLeadingUnquotedString arg
+        case str of
+            '=':_ ->
+                return $ err (headId arg) 2290 $
+                    "Remove spaces around = to assign."
+            '+':'=':_ ->
+                return $ err (headId arg) 2290 $
+                    "Remove spaces around += to append."
+            _ -> Nothing
+
+       -- 'let' is parsed as a sequence of arithmetic expansions,
+       -- so we want the additional warning for "x="
+      when (cmd == "let") $ sequence_ $ do
+        token <- getTrailingUnquotedLiteral arg
+        str <- getLiteralString token
+        guard $ "=" `isSuffixOf` str
+        return $ err (getId token) 2290 $
+            "Remove spaces around = to assign."
+
+    headId t =
+        case t of
+            T_NormalWord _ (x:_) -> getId x
+            _ -> getId t
+
+
+prop_checkMaskedReturns1 = verify (checkMaskedReturns "local") "f() { local a=$(false); }"
+prop_checkMaskedReturns2 = verify (checkMaskedReturns "declare") "declare a=$(false)"
+prop_checkMaskedReturns3 = verify (checkMaskedReturns "declare") "declare a=\"`false`\""
+prop_checkMaskedReturns4 = verify (checkMaskedReturns "readonly") "readonly a=$(false)"
+prop_checkMaskedReturns5 = verify (checkMaskedReturns "readonly") "readonly a=\"`false`\""
+prop_checkMaskedReturns6 = verifyNot (checkMaskedReturns "declare") "declare a; a=$(false)"
+prop_checkMaskedReturns7 = verifyNot (checkMaskedReturns "local") "f() { local -r a=$(false); }"
+prop_checkMaskedReturns8 = verifyNot (checkMaskedReturns "readonly") "a=$(false); readonly a"
+prop_checkMaskedReturns9 = verify (checkMaskedReturns "typeset") "#!/bin/ksh\n f() { typeset -r x=$(false); }"
+prop_checkMaskedReturns10 = verifyNot (checkMaskedReturns "typeset") "#!/bin/ksh\n function f { typeset -r x=$(false); }"
+prop_checkMaskedReturns11 = verifyNot (checkMaskedReturns "typeset") "#!/bin/bash\n f() { typeset -r x=$(false); }"
+prop_checkMaskedReturns12 = verify (checkMaskedReturns "typeset") "typeset -r x=$(false);"
+prop_checkMaskedReturns13 = verify (checkMaskedReturns "typeset") "f() { typeset -g x=$(false); }"
+prop_checkMaskedReturns14 = verify (checkMaskedReturns "declare") "declare x=${ false; }"
+prop_checkMaskedReturns15 = verify (checkMaskedReturns "declare") "f() { declare x=$(false); }"
+checkMaskedReturns str = CommandCheck (Exactly str) checkCmd
+  where
+    checkCmd t = do
+        path <- getPathM t
+        shell <- asks shellType
+        sequence_ $ do
+            name <- getCommandName t
+
+            let flags = map snd (getAllFlags t)
+            let hasDashR =  "r" `elem` flags
+            let hasDashG =  "g" `elem` flags
+            let isInScopedFunction = any (isScopedFunction shell) path
+
+            let isLocal = not hasDashG && isLocalInFunction name && isInScopedFunction
+            let isReadOnly = name == "readonly" || hasDashR
+
+            -- Don't warn about local variables that are declared readonly,
+            -- because the workaround `local x; x=$(false); local -r x;` is annoying
+            guard . not $ isLocal && isReadOnly
+
+            return $ mapM_ checkArgs $ arguments t
+
+    checkArgs (T_Assignment id _ _ _ word) | any hasReturn $ getWordParts word =
+        warn id 2155 "Declare and assign separately to avoid masking return values."
+    checkArgs _ = return ()
+
+    isLocalInFunction = (`elem` ["local", "declare", "typeset"])
+    isScopedFunction shell t =
+        case t of
+            T_BatsTest {} -> True
+            -- In ksh, only functions declared with 'function' have their own scope
+            T_Function _ (FunctionKeyword hasFunction) _ _ _ -> shell /= Ksh || hasFunction
+            _ -> False
+
+    hasReturn t = case t of
+        T_Backticked {} -> True
+        T_DollarExpansion {} -> True
+        T_DollarBraceCommandExpansion {} -> True
+        _ -> False
+
+
+prop_checkUnquotedEchoSpaces1 = verify checkUnquotedEchoSpaces "echo foo         bar"
+prop_checkUnquotedEchoSpaces2 = verifyNot checkUnquotedEchoSpaces "echo       foo"
+prop_checkUnquotedEchoSpaces3 = verifyNot checkUnquotedEchoSpaces "echo foo  bar"
+prop_checkUnquotedEchoSpaces4 = verifyNot checkUnquotedEchoSpaces "echo 'foo          bar'"
+prop_checkUnquotedEchoSpaces5 = verifyNot checkUnquotedEchoSpaces "echo a > myfile.txt b"
+prop_checkUnquotedEchoSpaces6 = verifyNot checkUnquotedEchoSpaces "        echo foo\\\n        bar"
+checkUnquotedEchoSpaces = CommandCheck (Basename "echo") check
+  where
+    check t = do
+        let args = arguments t
+        m <- asks tokenPositions
+        redir <- getClosestCommandM t
+        sequence_ $ do
+            let positions = mapMaybe (\c -> M.lookup (getId c) m) args
+            let pairs = zip positions (drop 1 positions)
+            (T_Redirecting _ redirTokens _) <- redir
+            let redirPositions = mapMaybe (\c -> fst <$> M.lookup (getId c) m) redirTokens
+            guard $ any (hasSpacesBetween redirPositions) pairs
+            return $ info (getId t) 2291 "Quote repeated spaces to avoid them collapsing into one."
+
+    hasSpacesBetween redirs ((a,b), (c,d)) =
+        posLine a == posLine d
+        && ((posColumn c) - (posColumn b)) >= 4
+        && not (any (\x -> b < x && x < c) redirs)
+
+
+prop_checkEvalArray1 = verify checkEvalArray  "eval $@"
+prop_checkEvalArray2 = verify checkEvalArray  "eval \"${args[@]}\""
+prop_checkEvalArray3 = verify checkEvalArray  "eval \"${args[@]@Q}\""
+prop_checkEvalArray4 = verifyNot checkEvalArray  "eval \"${args[*]@Q}\""
+prop_checkEvalArray5 = verifyNot checkEvalArray  "eval \"$*\""
+checkEvalArray = CommandCheck (Exactly "eval") (mapM_ check . concatMap getWordParts . arguments)
+  where
+    check t =
+        when (isArrayExpansion t) $
+            if isEscaped t
+            then style (getId t) 2293 "When eval'ing @Q-quoted words, use * rather than @ as the index."
+            else warn (getId t) 2294 "eval negates the benefit of arrays. Drop eval to preserve whitespace/symbols (or eval as string)."
+
+    isEscaped q =
+        case q of
+            -- Match ${arr[@]@Q} and ${@@Q} and such
+            T_DollarBraced _ _ l -> 'Q' `elem` getBracedModifier (concat $ oversimplify l)
+            _ -> False
+
+
+prop_checkBackreferencingDeclaration1 = verify (checkBackreferencingDeclaration "declare") "declare x=1 y=foo$x"
+prop_checkBackreferencingDeclaration2 = verify (checkBackreferencingDeclaration "readonly") "readonly x=1 y=$((1+x))"
+prop_checkBackreferencingDeclaration3 = verify (checkBackreferencingDeclaration "local") "local x=1 y=$(echo $x)"
+prop_checkBackreferencingDeclaration4 = verify (checkBackreferencingDeclaration "local") "local x=1 y[$x]=z"
+prop_checkBackreferencingDeclaration5 = verify (checkBackreferencingDeclaration "declare") "declare x=var $x=1"
+prop_checkBackreferencingDeclaration6 = verify (checkBackreferencingDeclaration "declare") "declare x=var $x=1"
+prop_checkBackreferencingDeclaration7 = verify (checkBackreferencingDeclaration "declare") "declare x=var $k=$x"
+checkBackreferencingDeclaration cmd = CommandCheck (Exactly cmd) check
+  where
+    check t = do
+        maybeCfga <- asks cfgAnalysis
+        mapM_ (\cfga -> foldM_ (perArg cfga) M.empty $ arguments t) maybeCfga
+
+    perArg cfga leftArgs t =
+        case t of
+            T_Assignment id _ name idx t -> do
+                warnIfBackreferencing cfga leftArgs $ t:idx
+                return $ M.insert name id leftArgs
+            t -> do
+                warnIfBackreferencing cfga leftArgs [t]
+                return leftArgs
+
+    warnIfBackreferencing cfga backrefs l = do
+        references <- findReferences cfga l
+        let reused = M.intersection backrefs references
+        mapM msg $ M.toList reused
+
+    msg (name, id) = warn id 2318 $ "This assignment is used again in this '" ++ cmd ++ "', but won't have taken effect. Use two '" ++ cmd ++ "'s."
+
+    findReferences cfga list = do
+        let graph = CF.graph cfga
+        let nodesMap = CF.tokenToNodes cfga
+        let nodes = S.unions $ map (\id -> M.findWithDefault S.empty id nodesMap) $ map getId $ list
+        let labels = mapMaybe (G.lab graph) $ S.toList nodes
+        let references = M.fromList $ concatMap refFromLabel labels
+        return references
+
+    refFromLabel lab =
+        case lab of
+            CFApplyEffects effects -> mapMaybe refFromEffect effects
+            _ -> []
+    refFromEffect e =
+        case e of
+            IdTagged id (CFReadVariable name) -> return (name, id)
+            _ -> Nothing
+
+
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Checks/ControlFlow.hs

@@ -0,0 +1,101 @@
+{-
+    Copyright 2022 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+
+-- Checks that run on the Control Flow Graph (as opposed to the AST)
+-- This is scaffolding for a work in progress.
+
+module ShellCheck.Checks.ControlFlow (checker, optionalChecks, ShellCheck.Checks.ControlFlow.runTests) where
+
+import ShellCheck.AST
+import ShellCheck.ASTLib
+import ShellCheck.CFG hiding (cfgAnalysis)
+import ShellCheck.CFGAnalysis
+import ShellCheck.AnalyzerLib
+import ShellCheck.Data
+import ShellCheck.Interface
+
+import Control.Monad
+import Control.Monad.Reader
+import Data.Graph.Inductive.Graph
+import qualified Data.Map as M
+import qualified Data.Set as S
+import Data.List
+import Data.Maybe
+
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
+
+
+optionalChecks :: [CheckDescription]
+optionalChecks = []
+
+-- A check that runs on the entire graph
+type ControlFlowCheck = Analysis
+-- A check invoked once per node, with its (pre,post) data
+type ControlFlowNodeCheck = LNode CFNode -> (ProgramState, ProgramState) -> Analysis
+-- A check invoked once per effect, with its node's (pre,post) data
+type ControlFlowEffectCheck = IdTagged CFEffect -> Node -> (ProgramState, ProgramState) -> Analysis
+
+
+checker :: AnalysisSpec -> Parameters -> Checker
+checker spec params = Checker {
+    perScript = const $ sequence_ controlFlowChecks,
+    perToken = const $ return ()
+}
+
+controlFlowChecks :: [ControlFlowCheck]
+controlFlowChecks = [
+        runNodeChecks controlFlowNodeChecks
+    ]
+
+controlFlowNodeChecks :: [ControlFlowNodeCheck]
+controlFlowNodeChecks = [
+    runEffectChecks controlFlowEffectChecks
+    ]
+
+controlFlowEffectChecks :: [ControlFlowEffectCheck]
+controlFlowEffectChecks = [
+    ]
+
+runNodeChecks :: [ControlFlowNodeCheck] -> ControlFlowCheck
+runNodeChecks perNode = do
+    cfg <- asks cfgAnalysis
+    mapM_ runOnAll cfg
+  where
+    getData datas n@(node, label) = do
+        (pre, post) <- M.lookup node datas
+        return (n, (pre, post))
+
+    runOn :: (LNode CFNode, (ProgramState, ProgramState)) -> Analysis
+    runOn (node, prepost) = mapM_ (\c -> c node prepost) perNode
+    runOnAll cfg = mapM_ runOn $ mapMaybe (getData $ nodeToData cfg) $ labNodes (graph cfg)
+
+runEffectChecks :: [ControlFlowEffectCheck] -> ControlFlowNodeCheck
+runEffectChecks list = checkNode
+  where
+    checkNode (node, label) prepost =
+        case label of
+            CFApplyEffects effects -> mapM_ (\effect -> mapM_ (\c -> c effect node prepost) list) effects
+            _ -> return ()
+
+
+return []
+runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Checks/ShellSupport.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2016 Vidar Holen
+    Copyright 2012-2020 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -19,12 +19,14 @@
 -}
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE ViewPatterns #-}
 module ShellCheck.Checks.ShellSupport (checker , ShellCheck.Checks.ShellSupport.runTests) where
 
 import ShellCheck.AST
 import ShellCheck.ASTLib
 import ShellCheck.AnalyzerLib
 import ShellCheck.Interface
+import ShellCheck.Prelude
 import ShellCheck.Regex
 
 import Control.Monad
@@ -59,6 +61,9 @@ checks = [
     ,checkBraceExpansionVars
     ,checkMultiDimensionalArrays
     ,checkPS1Assignments
+    ,checkMultipleBangs
+    ,checkBangAfterPipe
+    ,checkNegatedUnaryOps
     ]
 
 testChecker (ForShell _ t) =
@@ -72,74 +77,79 @@ verifyNot c s = producesComments (testChecker c) s == Just False
 prop_checkForDecimals1 = verify checkForDecimals "((3.14*c))"
 prop_checkForDecimals2 = verify checkForDecimals "foo[1.2]=bar"
 prop_checkForDecimals3 = verifyNot checkForDecimals "declare -A foo; foo[1.2]=bar"
-checkForDecimals = ForShell [Sh, Dash, Bash] f
+checkForDecimals = ForShell [Sh, Dash, BusyboxSh, Bash] f
   where
     f t@(TA_Expansion id _) = sequence_ $ do
-        str <- getLiteralString t
+        first:rest <- getLiteralString t
-        first <- str !!! 0
+        guard $ isDigit first && '.' `elem` rest
-        guard $ isDigit first && '.' `elem` str
         return $ err id 2079 "(( )) doesn't support decimals. Use bc or awk."
     f _ = return ()
 
 
 prop_checkBashisms = verify checkBashisms "while read a; do :; done < <(a)"
-prop_checkBashisms2 = verify checkBashisms "[ foo -nt bar ]"
+prop_checkBashisms2 = verifyNot checkBashisms "[ foo -nt bar ]"
 prop_checkBashisms3 = verify checkBashisms "echo $((i++))"
 prop_checkBashisms4 = verify checkBashisms "rm !(*.hs)"
 prop_checkBashisms5 = verify checkBashisms "source file"
 prop_checkBashisms6 = verify checkBashisms "[ \"$a\" == 42 ]"
+prop_checkBashisms6b = verify checkBashisms "test \"$a\" == 42"
+prop_checkBashisms6c = verify checkBashisms "[ foo =~ bar ]"
+prop_checkBashisms6d = verify checkBashisms "test foo =~ bar"
 prop_checkBashisms7 = verify checkBashisms "echo ${var[1]}"
 prop_checkBashisms8 = verify checkBashisms "echo ${!var[@]}"
 prop_checkBashisms9 = verify checkBashisms "echo ${!var*}"
-prop_checkBashisms10= verify checkBashisms "echo ${var:4:12}"
+prop_checkBashisms10 = verify checkBashisms "echo ${var:4:12}"
-prop_checkBashisms11= verifyNot checkBashisms "echo ${var:-4}"
+prop_checkBashisms11 = verifyNot checkBashisms "echo ${var:-4}"
-prop_checkBashisms12= verify checkBashisms "echo ${var//foo/bar}"
+prop_checkBashisms12 = verify checkBashisms "echo ${var//foo/bar}"
-prop_checkBashisms13= verify checkBashisms "exec -c env"
+prop_checkBashisms13 = verify checkBashisms "exec -c env"
-prop_checkBashisms14= verify checkBashisms "echo -n \"Foo: \""
+prop_checkBashisms14 = verify checkBashisms "echo -n \"Foo: \""
-prop_checkBashisms15= verify checkBashisms "let n++"
+prop_checkBashisms15 = verify checkBashisms "let n++"
-prop_checkBashisms16= verify checkBashisms "echo $RANDOM"
+prop_checkBashisms16 = verify checkBashisms "echo $RANDOM"
-prop_checkBashisms17= verify checkBashisms "echo $((RANDOM%6+1))"
+prop_checkBashisms17 = verify checkBashisms "echo $((RANDOM%6+1))"
-prop_checkBashisms18= verify checkBashisms "foo &> /dev/null"
+prop_checkBashisms18 = verify checkBashisms "foo &> /dev/null"
-prop_checkBashisms19= verify checkBashisms "foo > file*.txt"
+prop_checkBashisms19 = verify checkBashisms "foo > file*.txt"
-prop_checkBashisms20= verify checkBashisms "read -ra foo"
+prop_checkBashisms20 = verify checkBashisms "read -ra foo"
-prop_checkBashisms21= verify checkBashisms "[ -a foo ]"
+prop_checkBashisms21 = verify checkBashisms "[ -a foo ]"
-prop_checkBashisms22= verifyNot checkBashisms "[ foo -a bar ]"
+prop_checkBashisms21b = verify checkBashisms "test -a foo"
-prop_checkBashisms23= verify checkBashisms "trap mything ERR INT"
+prop_checkBashisms22 = verifyNot checkBashisms "[ foo -a bar ]"
-prop_checkBashisms24= verifyNot checkBashisms "trap mything INT TERM"
+prop_checkBashisms23 = verify checkBashisms "trap mything ERR INT"
-prop_checkBashisms25= verify checkBashisms "cat < /dev/tcp/host/123"
+prop_checkBashisms24 = verifyNot checkBashisms "trap mything INT TERM"
-prop_checkBashisms26= verify checkBashisms "trap mything ERR SIGTERM"
+prop_checkBashisms25 = verify checkBashisms "cat < /dev/tcp/host/123"
-prop_checkBashisms27= verify checkBashisms "echo *[^0-9]*"
+prop_checkBashisms26 = verify checkBashisms "trap mything ERR SIGTERM"
-prop_checkBashisms28= verify checkBashisms "exec {n}>&2"
+prop_checkBashisms27 = verify checkBashisms "echo *[^0-9]*"
-prop_checkBashisms29= verify checkBashisms "echo ${!var}"
+prop_checkBashisms28 = verify checkBashisms "exec {n}>&2"
-prop_checkBashisms30= verify checkBashisms "printf -v '%s' \"$1\""
+prop_checkBashisms29 = verify checkBashisms "echo ${!var}"
-prop_checkBashisms31= verify checkBashisms "printf '%q' \"$1\""
+prop_checkBashisms30 = verify checkBashisms "printf -v '%s' \"$1\""
-prop_checkBashisms32= verifyNot checkBashisms "#!/bin/dash\n[ foo -nt bar ]"
+prop_checkBashisms31 = verify checkBashisms "printf '%q' \"$1\""
-prop_checkBashisms33= verify checkBashisms "#!/bin/sh\necho -n foo"
+prop_checkBashisms32 = verifyNot checkBashisms "#!/bin/dash\n[ foo -nt bar ]"
-prop_checkBashisms34= verifyNot checkBashisms "#!/bin/dash\necho -n foo"
+prop_checkBashisms33 = verify checkBashisms "#!/bin/sh\necho -n foo"
-prop_checkBashisms35= verifyNot checkBashisms "#!/bin/dash\nlocal foo"
+prop_checkBashisms34 = verifyNot checkBashisms "#!/bin/dash\necho -n foo"
-prop_checkBashisms36= verifyNot checkBashisms "#!/bin/dash\nread -p foo -r bar"
+prop_checkBashisms35 = verifyNot checkBashisms "#!/bin/dash\nlocal foo"
-prop_checkBashisms37= verifyNot checkBashisms "HOSTNAME=foo; echo $HOSTNAME"
+prop_checkBashisms36 = verifyNot checkBashisms "#!/bin/dash\nread -p foo -r bar"
-prop_checkBashisms38= verify checkBashisms "RANDOM=9; echo $RANDOM"
+prop_checkBashisms37 = verifyNot checkBashisms "HOSTNAME=foo; echo $HOSTNAME"
-prop_checkBashisms39= verify checkBashisms "foo-bar() { true; }"
+prop_checkBashisms38 = verify checkBashisms "RANDOM=9; echo $RANDOM"
-prop_checkBashisms40= verify checkBashisms "echo $(<file)"
+prop_checkBashisms39 = verify checkBashisms "foo-bar() { true; }"
-prop_checkBashisms41= verify checkBashisms "echo `<file`"
+prop_checkBashisms40 = verify checkBashisms "echo $(<file)"
-prop_checkBashisms42= verify checkBashisms "trap foo int"
+prop_checkBashisms41 = verify checkBashisms "echo `<file`"
-prop_checkBashisms43= verify checkBashisms "trap foo sigint"
+prop_checkBashisms42 = verify checkBashisms "trap foo int"
-prop_checkBashisms44= verifyNot checkBashisms "#!/bin/dash\ntrap foo int"
+prop_checkBashisms43 = verify checkBashisms "trap foo sigint"
-prop_checkBashisms45= verifyNot checkBashisms "#!/bin/dash\ntrap foo INT"
+prop_checkBashisms44 = verifyNot checkBashisms "#!/bin/dash\ntrap foo int"
-prop_checkBashisms46= verify checkBashisms "#!/bin/dash\ntrap foo SIGINT"
+prop_checkBashisms45 = verifyNot checkBashisms "#!/bin/dash\ntrap foo INT"
-prop_checkBashisms47= verify checkBashisms "#!/bin/dash\necho foo 42>/dev/null"
+prop_checkBashisms46 = verify checkBashisms "#!/bin/dash\ntrap foo SIGINT"
-prop_checkBashisms48= verifyNot checkBashisms "#!/bin/sh\necho $LINENO"
+prop_checkBashisms47 = verify checkBashisms "#!/bin/dash\necho foo 42>/dev/null"
-prop_checkBashisms49= verify checkBashisms "#!/bin/dash\necho $MACHTYPE"
+prop_checkBashisms48 = verifyNot checkBashisms "#!/bin/sh\necho $LINENO"
-prop_checkBashisms50= verify checkBashisms "#!/bin/sh\ncmd >& file"
+prop_checkBashisms49 = verify checkBashisms "#!/bin/dash\necho $MACHTYPE"
-prop_checkBashisms51= verifyNot checkBashisms "#!/bin/sh\ncmd 2>&1"
+prop_checkBashisms50 = verify checkBashisms "#!/bin/sh\ncmd >& file"
-prop_checkBashisms52= verifyNot checkBashisms "#!/bin/sh\ncmd >&2"
+prop_checkBashisms51 = verifyNot checkBashisms "#!/bin/sh\ncmd 2>&1"
-prop_checkBashisms53= verifyNot checkBashisms "#!/bin/sh\nprintf -- -f\n"
+prop_checkBashisms52 = verifyNot checkBashisms "#!/bin/sh\ncmd >&2"
-prop_checkBashisms54= verify checkBashisms "#!/bin/sh\nfoo+=bar"
+prop_checkBashisms52b = verifyNot checkBashisms "#!/bin/sh\ncmd >& $var"
-prop_checkBashisms55= verify checkBashisms "#!/bin/sh\necho ${@%foo}"
+prop_checkBashisms52c = verify checkBashisms "#!/bin/sh\ncmd >& $dir/$var"
-prop_checkBashisms56= verifyNot checkBashisms "#!/bin/sh\necho ${##}"
+prop_checkBashisms53 = verifyNot checkBashisms "#!/bin/sh\nprintf -- -f\n"
-prop_checkBashisms57= verifyNot checkBashisms "#!/bin/dash\nulimit -c 0"
+prop_checkBashisms54 = verify checkBashisms "#!/bin/sh\nfoo+=bar"
-prop_checkBashisms58= verify checkBashisms "#!/bin/sh\nulimit -c 0"
+prop_checkBashisms55 = verify checkBashisms "#!/bin/sh\necho ${@%foo}"
+prop_checkBashisms56 = verifyNot checkBashisms "#!/bin/sh\necho ${##}"
+prop_checkBashisms57 = verifyNot checkBashisms "#!/bin/dash\nulimit -c 0"
+prop_checkBashisms58 = verify checkBashisms "#!/bin/sh\nulimit -c 0"
 prop_checkBashisms59 = verify checkBashisms "#!/bin/sh\njobs -s"
 prop_checkBashisms60 = verifyNot checkBashisms "#!/bin/sh\njobs -p"
 prop_checkBashisms61 = verifyNot checkBashisms "#!/bin/sh\njobs -lp"
@@ -180,51 +190,85 @@ prop_checkBashisms95 = verify checkBashisms "#!/bin/sh\necho $_"
 prop_checkBashisms96 = verifyNot checkBashisms "#!/bin/dash\necho $_"
 prop_checkBashisms97 = verify checkBashisms "#!/bin/sh\necho ${var,}"
 prop_checkBashisms98 = verify checkBashisms "#!/bin/sh\necho ${var^^}"
-prop_checkBashisms99 = verifyNot checkBashisms "#!/bin/dash\necho [^f]oo"
+prop_checkBashisms99 = verify checkBashisms "#!/bin/dash\necho [^f]oo"
-checkBashisms = ForShell [Sh, Dash] $ \t -> do
+prop_checkBashisms100 = verify checkBashisms "read -r"
+prop_checkBashisms101 = verify checkBashisms "read"
+prop_checkBashisms102 = verifyNot checkBashisms "read -r foo"
+prop_checkBashisms103 = verifyNot checkBashisms "read foo"
+prop_checkBashisms104 = verifyNot checkBashisms "read ''"
+prop_checkBashisms105 = verifyNot checkBashisms "#!/bin/busybox sh\nset -o pipefail"
+prop_checkBashisms106 = verifyNot checkBashisms "#!/bin/busybox sh\nx=x\n[[ \"$x\" = \"$x\" ]]"
+prop_checkBashisms107 = verifyNot checkBashisms "#!/bin/busybox sh\nx=x\n[ \"$x\" == \"$x\" ]"
+prop_checkBashisms108 = verifyNot checkBashisms "#!/bin/busybox sh\necho magic &> /dev/null"
+prop_checkBashisms109 = verifyNot checkBashisms "#!/bin/busybox sh\ntrap stop EXIT SIGTERM"
+prop_checkBashisms110 = verifyNot checkBashisms "#!/bin/busybox sh\nsource /dev/null"
+prop_checkBashisms111 = verify checkBashisms "#!/bin/dash\nx='test'\n${x:0:3}" -- SC3057
+prop_checkBashisms112 = verifyNot checkBashisms "#!/bin/busybox sh\nx='test'\n${x:0:3}" -- SC3057
+prop_checkBashisms113 = verify checkBashisms "#!/bin/dash\nx='test'\n${x/st/xt}" -- SC3060
+prop_checkBashisms114 = verifyNot checkBashisms "#!/bin/busybox sh\nx='test'\n${x/st/xt}" -- SC3060
+prop_checkBashisms115 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${!x}" -- SC3053
+prop_checkBashisms116 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${x[1]}" -- SC3054
+prop_checkBashisms117 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${!x[@]}" -- SC3055
+prop_checkBashisms118 = verify checkBashisms "#!/bin/busybox sh\nxyz=1\n${!x*}" -- SC3056
+prop_checkBashisms119 = verify checkBashisms "#!/bin/busybox sh\nx='test'\n${x^^[t]}" -- SC3059
+prop_checkBashisms120 = verify checkBashisms "#!/bin/sh\n[ x == y ]"
+prop_checkBashisms121 = verifyNot checkBashisms "#!/bin/sh\n# shellcheck shell=busybox\n[ x == y ]"
+prop_checkBashisms122 = verify checkBashisms "#!/bin/dash\n$'a'"
+prop_checkBashisms123 = verifyNot checkBashisms "#!/bin/busybox sh\n$'a'"
+prop_checkBashisms124 = verify checkBashisms "#!/bin/dash\ntype -p test"
+prop_checkBashisms125 = verifyNot checkBashisms "#!/bin/busybox sh\ntype -p test"
+prop_checkBashisms126 = verifyNot checkBashisms "#!/bin/busybox sh\nread -p foo -r bar"
+prop_checkBashisms127 = verifyNot checkBashisms "#!/bin/busybox sh\necho -ne foo"
+prop_checkBashisms128 = verify checkBashisms "#!/bin/dash\ntype -p test"
+prop_checkBashisms129 = verify checkBashisms "#!/bin/sh\n[ -k /tmp ]"
+prop_checkBashisms130 = verifyNot checkBashisms "#!/bin/dash\ntest -k /tmp"
+prop_checkBashisms131 = verify checkBashisms "#!/bin/sh\n[ -o errexit ]"
+checkBashisms = ForShell [Sh, Dash, BusyboxSh] $ \t -> do
     params <- ask
     kludge params t
  where
   -- This code was copy-pasted from Analytics where params was a variable
   kludge params = bashism
    where
-    isDash = shellType params == Dash
+    isBusyboxSh = shellType params == BusyboxSh
+    isDash = shellType params == Dash || isBusyboxSh
     warnMsg id code s =
         if isDash
         then err  id code $ "In dash, " ++ s ++ " not supported."
         else warn id code $ "In POSIX sh, " ++ s ++ " undefined."
+    asStr = getLiteralString
 
     bashism (T_ProcSub id _ _) = warnMsg id 3001 "process substitution is"
     bashism (T_Extglob id _ _) = warnMsg id 3002 "extglob is"
-    bashism (T_DollarSingleQuoted id _) = warnMsg id 3003 "$'..' is"
+    bashism (T_DollarSingleQuoted id _) =
+        unless isBusyboxSh $ warnMsg id 3003 "$'..' is"
     bashism (T_DollarDoubleQuoted id _) = warnMsg id 3004 "$\"..\" is"
     bashism (T_ForArithmetic id _ _ _ _) = warnMsg id 3005 "arithmetic for loops are"
     bashism (T_Arithmetic id _) = warnMsg id 3006 "standalone ((..)) is"
     bashism (T_DollarBracket id _) = warnMsg id 3007 "$[..] in place of $((..)) is"
     bashism (T_SelectIn id _ _ _) = warnMsg id 3008 "select loops are"
     bashism (T_BraceExpansion id _) = warnMsg id 3009 "brace expansion is"
-    bashism (T_Condition id DoubleBracket _) = warnMsg id 3010 "[[ ]] is"
+    bashism (T_Condition id DoubleBracket _) =
+        unless isBusyboxSh $ warnMsg id 3010 "[[ ]] is"
     bashism (T_HereString id _) = warnMsg id 3011 "here-strings are"
-    bashism (TC_Binary id SingleBracket op _ _)
+
-        | op `elem` [ "<", ">", "\\<", "\\>", "<=", ">=", "\\<=", "\\>="] =
+    bashism (TC_Binary id _ op _ _) =
-            unless isDash $ warnMsg id 3012 $ "lexicographical " ++ op ++ " is"
+        checkTestOp bashismBinaryTestFlags op id
-    bashism (TC_Binary id SingleBracket op _ _)
+    bashism (T_SimpleCommand id _ [asStr -> Just "test", lhs, asStr -> Just op, rhs]) =
-        | op `elem` [ "-ot", "-nt", "-ef" ] =
+        checkTestOp bashismBinaryTestFlags op id
-            unless isDash $ warnMsg id 3013 $ op ++ " is"
+    bashism (TC_Unary id _ op _) =
-    bashism (TC_Binary id SingleBracket "==" _ _) =
+        checkTestOp bashismUnaryTestFlags op id
-            warnMsg id 3014 "== in place of = is"
+    bashism (T_SimpleCommand id _ [asStr -> Just "test", asStr -> Just op, _]) =
-    bashism (TC_Binary id SingleBracket "=~" _ _) =
+        checkTestOp bashismUnaryTestFlags op id
-            warnMsg id 3015 "=~ regex matching is"
+
-    bashism (TC_Unary id SingleBracket "-v" _) =
-            warnMsg id 3016 "unary -v (in place of [ -n \"${var+x}\" ]) is"
-    bashism (TC_Unary id _ "-a" _) =
-            warnMsg id 3017 "unary -a in place of -e is"
     bashism (TA_Unary id op _)
         | op `elem` [ "|++", "|--", "++|", "--|"] =
             warnMsg id 3018 $ filter (/= '|') op ++ " is"
     bashism (TA_Binary id "**" _ _) = warnMsg id 3019 "exponentials are"
-    bashism (T_FdRedirect id "&" (T_IoFile _ (T_Greater _) _)) = warnMsg id 3020 "&> is"
+    bashism (T_FdRedirect id "&" (T_IoFile _ (T_Greater _) _)) =
-    bashism (T_FdRedirect id "" (T_IoFile _ (T_GREATAND _) _)) = warnMsg id 3021 ">& is"
+        unless isBusyboxSh $ warnMsg id 3020 "&> is"
+    bashism (T_FdRedirect id "" (T_IoFile _ (T_GREATAND _) file)) =
+        unless (all isDigit $ onlyLiteralString file) $ warnMsg id 3021 ">& filename (as opposed to >& fd) is"
     bashism (T_FdRedirect id ('{':_) _) = warnMsg id 3022 "named file descriptors are"
     bashism (T_FdRedirect id num _)
         | all isDigit num && length num > 1 = warnMsg id 3023 "FDs outside 0-9 are"
@@ -235,14 +279,15 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
         where
             file = onlyLiteralString word
             isNetworked = any (`isPrefixOf` file) ["/dev/tcp", "/dev/udp"]
-    bashism (T_Glob id str) | not isDash && "[^" `isInfixOf` str =
+    bashism (T_Glob id str) | "[^" `isInfixOf` str =
             warnMsg id 3026 "^ in place of ! in glob bracket expressions is"
 
     bashism t@(TA_Variable id str _) | isBashVariable str =
         warnMsg id 3028 $ str ++ " is"
 
     bashism t@(T_DollarBraced id _ token) = do
-        mapM_ check expansion
+        unless isBusyboxSh $ mapM_ check simpleExpansions
+        mapM_ check advancedExpansions
         when (isBashVariable var) $
             warnMsg id 3028 $ var ++ " is"
       where
@@ -270,7 +315,11 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
 
     bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
         | t `isCommand` "echo" && argString `matches` flagRegex =
-            if isDash
+            if isBusyboxSh
+            then
+                unless (argString `matches` busyboxFlagRegex) $
+                    warnMsg (getId arg) 3036 "echo flags besides -n and -e"
+            else if isDash
             then
                 when (argString /= "-n") $
                     warnMsg (getId arg) 3036 "echo flags besides -n"
@@ -279,6 +328,7 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
       where
           argString = concat $ oversimplify arg
           flagRegex = mkRegex "^-[eEsn]+$"
+          busyboxFlagRegex = mkRegex "^-[en]+$"
 
     bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
         | getLiteralString cmd == Just "exec" && "-" `isPrefixOf` concat (oversimplify arg) =
@@ -352,7 +402,8 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
                     (\x -> (not . null . snd $ x) && snd x `notElem` allowed) flags
                 return . warnMsg (getId word) 3045 $ name ++ " -" ++ flag ++ " is"
 
-            when (name == "source") $ warnMsg id 3046 "'source' in place of '.' is"
+            when (name == "source" && not isBusyboxSh) $
+                warnMsg id 3046 "'source' in place of '.' is"
             when (name == "trap") $
                 let
                     check token = sequence_ $ do
@@ -361,7 +412,7 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
                         return $ do
                             when (upper `elem` ["ERR", "DEBUG", "RETURN"]) $
                                 warnMsg (getId token) 3047 $ "trapping " ++ str ++ " is"
-                            when ("SIG" `isPrefixOf` upper) $
+                            when (not isBusyboxSh && "SIG" `isPrefixOf` upper) $
                                 warnMsg (getId token) 3048
                                     "prefixing signal names with 'SIG' is"
                             when (not isDash && upper /= str) $
@@ -375,6 +426,9 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
                 let literal = onlyLiteralString format
                 guard $ "%q" `isInfixOf` literal
                 return $ warnMsg (getId format) 3050 "printf %q is"
+
+            when (name == "read" && all isFlag rest) $
+                warnMsg (getId cmd) 3061 "read without a variable is"
       where
         unsupportedCommands = [
             "let", "caller", "builtin", "complete", "compgen", "declare", "dirs", "disown",
@@ -388,17 +442,19 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
             ("hash", Just $ if isDash then ["r", "v"] else ["r"]),
             ("jobs", Just ["l", "p"]),
             ("printf", Just []),
-            ("read", Just $ if isDash then ["r", "p"] else ["r"]),
+            ("read", Just $ if isDash || isBusyboxSh then ["r", "p"] else ["r"]),
             ("readonly", Just ["p"]),
             ("trap", Just []),
-            ("type", Just []),
+            ("type", Just $ if isBusyboxSh then ["p"] else []),
             ("ulimit", if isDash then Nothing else Just ["f"]),
             ("umask", Just ["S"]),
             ("unset", Just ["f", "v"]),
             ("wait", Just [])
             ]
     bashism t@(T_SourceCommand id src _)
-        | getCommandName src == Just "source" = warnMsg id 3051 "'source' in place of '.' is"
+      | getCommandName src == Just "source" =
+          unless isBusyboxSh $
+            warnMsg id 3051 "'source' in place of '.' is"
     bashism (TA_Expansion _ (T_Literal id str : _))
         | str `matches` radix = warnMsg id 3052 "arithmetic base conversion is"
       where
@@ -406,14 +462,16 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
     bashism _ = return ()
 
     varChars="_0-9a-zA-Z"
-    expansion = let re = mkRegex in [
+    advancedExpansions = let re = mkRegex in [
         (re $ "^![" ++ varChars ++ "]", 3053, "indirect expansion is"),
         (re $ "^[" ++ varChars ++ "]+\\[.*\\]$", 3054, "array references are"),
         (re $ "^![" ++ varChars ++ "]+\\[[*@]]$", 3055, "array key expansion is"),
         (re $ "^![" ++ varChars ++ "]+[*@]$", 3056, "name matching prefixes are"),
+        (re $ "^[" ++ varChars ++ "*@]+(\\[.*\\])?[,^]", 3059, "case modification is")
+        ]
+    simpleExpansions = let re = mkRegex in [
         (re $ "^[" ++ varChars ++ "*@]+:[^-=?+]", 3057, "string indexing is"),
         (re $ "^([*@][%#]|#[@*])", 3058, "string operations on $@/$* are"),
-        (re $ "^[" ++ varChars ++ "*@]+(\\[.*\\])?[,^]", 3059, "case modification is"),
         (re $ "^[" ++ varChars ++ "*@]+(\\[.*\\])?/", 3060, "string replacement is")
         ]
     bashVars = [
@@ -439,10 +497,54 @@ checkBashisms = ForShell [Sh, Dash] $ \t -> do
                 Assignment (_, _, name, _) -> name == var
                 _ -> False
 
+    checkTestOp table op id = sequence_ $ do
+        (code, shells, msg) <- Map.lookup op table
+        guard . not $ shellType params `elem` shells
+        return $ warnMsg id code (msg op)
+
+
+buildTestFlagMap list = Map.fromList $ concatMap (\(x,y) -> map (\c -> (c,y)) x) list
+bashismBinaryTestFlags = buildTestFlagMap [
+    -- ([list of applicable flags],
+    --     (error code, exempt shells, message builder :: String -> String)),
+    --
+    -- Distinct error codes allow the wiki to give more helpful, targeted
+    -- information.
+    (["<", ">", "\\<", "\\>", "<=", ">=", "\\<=", "\\>="],
+        (3012, [Dash, BusyboxSh], \op -> "lexicographical " ++ op ++ " is")),
+    (["=="],
+        (3014, [BusyboxSh], \op -> op ++ " in place of = is")),
+    (["=~"],
+        (3015, [], \op -> op ++ " regex matching is")),
+
+    ([], (0,[],const ""))
+  ]
+bashismUnaryTestFlags = buildTestFlagMap [
+    (["-v"],
+        (3016, [], \op -> "test " ++ op ++ " (in place of [ -n \"${var+x}\" ]) is")),
+    (["-a"],
+        (3017, [], \op -> "unary " ++ op ++ " in place of -e is")),
+    (["-o"],
+        (3062, [], \op -> "test " ++ op ++ " to check options is")),
+    (["-R"],
+        (3063, [], \op -> "test " ++ op ++ " and namerefs in general are")),
+    (["-N"],
+        (3064, [], \op -> "test " ++ op ++ " is")),
+    (["-k"],
+        (3065, [Dash, BusyboxSh], \op -> "test " ++ op ++ " is")),
+    (["-G"],
+        (3066, [Dash, BusyboxSh], \op -> "test " ++ op ++ " is")),
+    (["-O"],
+        (3067, [Dash, BusyboxSh], \op -> "test " ++ op ++ " is")),
+
+    ([], (0,[],const ""))
+  ]
+
+
 prop_checkEchoSed1 = verify checkEchoSed "FOO=$(echo \"$cow\" | sed 's/foo/bar/g')"
-prop_checkEchoSed1b= verify checkEchoSed "FOO=$(sed 's/foo/bar/g' <<< \"$cow\")"
+prop_checkEchoSed1b = verify checkEchoSed "FOO=$(sed 's/foo/bar/g' <<< \"$cow\")"
 prop_checkEchoSed2 = verify checkEchoSed "rm $(echo $cow | sed -e 's,foo,bar,')"
-prop_checkEchoSed2b= verify checkEchoSed "rm $(sed -e 's,foo,bar,' <<< $cow)"
+prop_checkEchoSed2b = verify checkEchoSed "rm $(sed -e 's,foo,bar,' <<< $cow)"
 checkEchoSed = ForShell [Bash, Ksh] f
   where
     f (T_Redirecting id lefts r) =
@@ -528,11 +630,11 @@ checkMultiDimensionalArrays = ForShell [Bash] f
     isMultiDim l = getBracedModifier (concat $ oversimplify l) `matches` re
 
 prop_checkPS11 = verify checkPS1Assignments "PS1='\\033[1;35m\\$ '"
-prop_checkPS11a= verify checkPS1Assignments "export PS1='\\033[1;35m\\$ '"
+prop_checkPS11a = verify checkPS1Assignments "export PS1='\\033[1;35m\\$ '"
 prop_checkPSf2 = verify checkPS1Assignments "PS1='\\h \\e[0m\\$ '"
 prop_checkPS13 = verify checkPS1Assignments "PS1=$'\\x1b[c '"
 prop_checkPS14 = verify checkPS1Assignments "PS1=$'\\e[3m; '"
-prop_checkPS14a= verify checkPS1Assignments "export PS1=$'\\e[3m; '"
+prop_checkPS14a = verify checkPS1Assignments "export PS1=$'\\e[3m; '"
 prop_checkPS15 = verifyNot checkPS1Assignments "PS1='\\[\\033[1;35m\\]\\$ '"
 prop_checkPS16 = verifyNot checkPS1Assignments "PS1='\\[\\e1m\\e[1m\\]\\$ '"
 prop_checkPS17 = verifyNot checkPS1Assignments "PS1='e033x1B'"
@@ -554,5 +656,46 @@ checkPS1Assignments = ForShell [Bash] f
     escapeRegex = mkRegex "\\\\x1[Bb]|\\\\e|\x1B|\\\\033"
 
 
+prop_checkMultipleBangs1 = verify checkMultipleBangs "! ! true"
+prop_checkMultipleBangs2 = verifyNot checkMultipleBangs "! true"
+checkMultipleBangs = ForShell [Dash, BusyboxSh, Sh] f
+  where
+    f token = case token of
+        T_Banged id (T_Banged _ _) ->
+            err id 2325 "Multiple ! in front of pipelines are a bash/ksh extension. Use only 0 or 1."
+        _ -> return ()
+
+
+prop_checkBangAfterPipe1 = verify checkBangAfterPipe "true | ! true"
+prop_checkBangAfterPipe2 = verifyNot checkBangAfterPipe "true | ( ! true )"
+prop_checkBangAfterPipe3 = verifyNot checkBangAfterPipe "! ! true | true"
+checkBangAfterPipe = ForShell [Dash, BusyboxSh, Sh, Bash] f
+  where
+    f token = case token of
+        T_Pipeline _ _ cmds -> mapM_ check cmds
+        _ -> return ()
+
+    check token = case token of
+        T_Banged id _ ->
+            err id 2326 "! is not allowed in the middle of pipelines. Use command group as in cmd | { ! cmd; } if necessary."
+        _ -> return ()
+
+
+prop_checkNegatedUnaryOps1 = verify checkNegatedUnaryOps "[ ! -o braceexpand ]"
+prop_checkNegatedUnaryOps2 = verifyNot checkNegatedUnaryOps "[ -o braceexpand ]"
+prop_checkNegatedUnaryOps3 = verifyNot checkNegatedUnaryOps "[[ ! -o braceexpand ]]"
+prop_checkNegatedUnaryOps4 = verifyNot checkNegatedUnaryOps "! [ -o braceexpand ]"
+prop_checkNegatedUnaryOps5 = verify checkNegatedUnaryOps "[ ! -a file ]"
+checkNegatedUnaryOps = ForShell [Bash] f
+  where
+    f token = case token of
+        TC_Unary id SingleBracket "!" (TC_Unary _ _ op _) | op `elem` ["-a", "-o"] ->
+            err id 2332 $ msg op
+        _ -> return ()
+
+    msg "-o" = "[ ! -o opt ] is always true because -o becomes logical OR. Use [[ ]] or ! [ -o opt ]."
+    msg "-a" = "[ ! -a file ] is always true because -a becomes logical AND. Use -e instead."
+    msg _ = pleaseReport "unhandled negated unary message"
+
 return []
 runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

src/ShellCheck/Data.hs

@@ -2,9 +2,27 @@ module ShellCheck.Data where
 
 import ShellCheck.Interface
 import Data.Version (showVersion)
-import Paths_ShellCheck (version)
 
-shellcheckVersion = showVersion version
+
+{-
+If you are here because you saw an error about Paths_ShellCheck in this file,
+simply comment out the import below and define the version as a constant string.
+
+Instead of:
+
+    import Paths_ShellCheck (version)
+    shellcheckVersion = showVersion version
+
+Use:
+
+    -- import Paths_ShellCheck (version)
+    shellcheckVersion = "kludge"
+
+-}
+
+import Paths_ShellCheck (version)
+shellcheckVersion = showVersion version  -- VERSIONSTRING
+
 
 internalVariables = [
     -- Generic
@@ -12,23 +30,27 @@ internalVariables = [
 
     -- Bash
     "BASH", "BASHOPTS", "BASHPID", "BASH_ALIASES", "BASH_ARGC",
-    "BASH_ARGV", "BASH_CMDS", "BASH_COMMAND", "BASH_EXECUTION_STRING",
+    "BASH_ARGV", "BASH_ARGV0", "BASH_CMDS", "BASH_COMMAND",
-    "BASH_LINENO", "BASH_REMATCH", "BASH_SOURCE", "BASH_SUBSHELL",
+    "BASH_EXECUTION_STRING", "BASH_LINENO", "BASH_LOADABLES_PATH",
-    "BASH_VERSINFO", "BASH_VERSION", "COMP_CWORD", "COMP_KEY",
+    "BASH_REMATCH", "BASH_SOURCE", "BASH_SUBSHELL", "BASH_VERSINFO",
-    "COMP_LINE", "COMP_POINT", "COMP_TYPE", "COMP_WORDBREAKS",
+    "BASH_VERSION", "COMP_CWORD", "COMP_KEY", "COMP_LINE", "COMP_POINT",
-    "COMP_WORDS", "COPROC", "DIRSTACK", "EUID", "FUNCNAME", "GROUPS",
+    "COMP_TYPE", "COMP_WORDBREAKS", "COMP_WORDS", "COPROC", "DIRSTACK",
-    "HISTCMD", "HOSTNAME", "HOSTTYPE", "LINENO", "MACHTYPE", "MAPFILE",
+    "EPOCHREALTIME", "EPOCHSECONDS", "EUID", "FUNCNAME", "GROUPS", "HISTCMD",
-    "OLDPWD", "OPTARG", "OPTIND", "OSTYPE", "PIPESTATUS", "PPID", "PWD",
+    "HOSTNAME", "HOSTTYPE", "LINENO", "MACHTYPE", "MAPFILE", "OLDPWD",
-    "RANDOM", "READLINE_LINE", "READLINE_POINT", "REPLY", "SECONDS",
+    "OPTARG", "OPTIND", "OSTYPE", "PIPESTATUS", "PPID", "PWD", "RANDOM",
-    "SHELLOPTS", "SHLVL", "UID", "BASH_ENV", "BASH_XTRACEFD", "CDPATH",
+    "READLINE_ARGUMENT", "READLINE_LINE", "READLINE_MARK", "READLINE_POINT",
-    "COLUMNS", "COMPREPLY", "EMACS", "ENV", "FCEDIT", "FIGNORE",
+    "REPLY", "SECONDS", "SHELLOPTS", "SHLVL", "SRANDOM", "UID", "BASH_COMPAT",
+    "BASH_ENV", "BASH_XTRACEFD", "CDPATH", "CHILD_MAX", "COLUMNS",
+    "COMPREPLY", "EMACS", "ENV", "EXECIGNORE", "FCEDIT", "FIGNORE",
     "FUNCNEST", "GLOBIGNORE", "HISTCONTROL", "HISTFILE", "HISTFILESIZE",
     "HISTIGNORE", "HISTSIZE", "HISTTIMEFORMAT", "HOME", "HOSTFILE", "IFS",
-    "IGNOREEOF", "INPUTRC", "LANG", "LC_ALL", "LC_COLLATE", "LC_CTYPE",
+    "IGNOREEOF", "INPUTRC", "INSIDE_EMACS", "LANG", "LC_ALL", "LC_COLLATE",
-    "LC_MESSAGES", "LC_MONETARY", "LC_NUMERIC", "LC_TIME", "LINES", "MAIL",
+    "LC_CTYPE", "LC_MESSAGES", "LC_MONETARY", "LC_NUMERIC", "LC_TIME",
-    "MAILCHECK", "MAILPATH", "OPTERR", "PATH", "POSIXLY_CORRECT",
+    "LINES", "MAIL", "MAILCHECK", "MAILPATH", "OPTERR", "PATH",
-    "PROMPT_COMMAND", "PROMPT_DIRTRIM", "PS1", "PS2", "PS3", "PS4", "SHELL",
+    "POSIXLY_CORRECT", "PROMPT_COMMAND", "PROMPT_DIRTRIM", "PS0", "PS1",
-    "TIMEFORMAT", "TMOUT", "TMPDIR", "auto_resume", "histchars", "COPROC",
+    "PS2", "PS3", "PS4", "SHELL", "TIMEFORMAT", "TMOUT", "TMPDIR",
+    "BASH_MONOSECONDS", "BASH_TRAPSIG", "GLOBSORT",
+    "auto_resume", "histchars",
 
     -- Other
     "USER", "TZ", "TERM", "LOGNAME", "LD_LIBRARY_PATH", "LANGUAGE", "DISPLAY",
@@ -41,15 +63,23 @@ internalVariables = [
     , "FLAGS_ARGC", "FLAGS_ARGV", "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_HELP",
     "FLAGS_PARENT", "FLAGS_RESERVED", "FLAGS_TRUE", "FLAGS_VERSION",
     "flags_error", "flags_return"
+
+    -- Bats
+    ,"stderr", "stderr_lines"
   ]
 
-specialVariablesWithoutSpaces = [
+specialIntegerVariables = [
-    "$", "-", "?", "!", "#"
+    "$", "?", "!", "#"
   ]
+
+specialVariablesWithoutSpaces = "-" : specialIntegerVariables
+
 variablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
-    "BASHPID", "BASH_ARGC", "BASH_LINENO", "BASH_SUBSHELL", "EUID", "LINENO",
+    "BASHPID", "BASH_ARGC", "BASH_LINENO", "BASH_SUBSHELL", "EUID",
-    "OPTIND", "PPID", "RANDOM", "SECONDS", "SHELLOPTS", "SHLVL", "UID",
+    "EPOCHREALTIME", "EPOCHSECONDS", "LINENO", "OPTIND", "PPID", "RANDOM",
-    "COLUMNS", "HISTFILESIZE", "HISTSIZE", "LINES"
+    "READLINE_ARGUMENT", "READLINE_MARK", "READLINE_POINT", "SECONDS",
+    "SHELLOPTS", "SHLVL", "SRANDOM", "UID", "COLUMNS", "HISTFILESIZE",
+    "HISTSIZE", "LINES", "BASH_MONOSECONDS", "BASH_TRAPSIG"
 
     -- shflags
     , "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_TRUE"
@@ -95,10 +125,10 @@ commonCommands = [
 
 nonReadingCommands = [
     "alias", "basename", "bg", "cal", "cd", "chgrp", "chmod", "chown",
-    "cp", "du", "echo", "export", "false", "fg", "fuser", "getconf",
+    "cp", "du", "echo", "export", "fg", "fuser", "getconf",
     "getopt", "getopts", "ipcrm", "ipcs", "jobs", "kill", "ln", "ls",
     "locale", "mv", "printf", "ps", "pwd", "renice", "rm", "rmdir",
-    "set", "sleep", "touch", "trap", "true", "ulimit", "unalias", "uname"
+    "set", "sleep", "touch", "trap", "ulimit", "unalias", "uname"
     ]
 
 sampleWords = [
@@ -130,11 +160,18 @@ shellForExecutable name =
         "sh"    -> return Sh
         "bash"  -> return Bash
         "bats"  -> return Bash
+        "busybox"  -> return BusyboxSh -- Used for directives and --shell=busybox
+        "busybox sh"  -> return BusyboxSh
+        "busybox ash"  -> return BusyboxSh
         "dash"  -> return Dash
         "ash"   -> return Dash -- There's also a warning for this.
         "ksh"   -> return Ksh
         "ksh88" -> return Ksh
         "ksh93" -> return Ksh
+        "oksh"  -> return Ksh
         _ -> Nothing
 
 flagsForRead = "sreu:n:N:i:p:a:t:"
+flagsForMapfile = "d:n:O:s:u:C:c:t"
+
+declaringCommands = ["local", "declare", "export", "readonly", "typeset", "let"]

src/ShellCheck/Debug.hs

@@ -0,0 +1,313 @@
+{-
+
+This file contains useful functions for debugging and developing ShellCheck.
+
+To invoke them interactively, run:
+
+    cabal repl
+
+At the ghci prompt, enter:
+
+    :load ShellCheck.Debug
+
+You can now invoke the functions. Here are some examples:
+
+    shellcheckString "echo $1"
+    stringToAst "(( x+1 ))"
+    stringToCfg "if foo; then bar; else baz; fi"
+    writeFile "/tmp/test.dot" $ stringToCfgViz "while foo; do bar; done"
+
+The latter file can be rendered to png with GraphViz:
+
+    dot -Tpng /tmp/test.dot > /tmp/test.png
+
+To run all unit tests in a module:
+
+    ShellCheck.Parser.runTests
+    ShellCheck.Analytics.runTests
+
+To run a specific test:
+
+    :load ShellCheck.Analytics
+    prop_checkUuoc3
+
+If you make code changes, reload in seconds at any time with:
+
+    :r
+
+===========================================================================
+
+Crash course in printf debugging in Haskell:
+
+    import Debug.Trace
+
+    greet 0 = return ()
+    -- Print when a function is invoked
+    greet n | trace ("calling greet " ++ show n) False = undefined
+    greet n = do
+        putStrLn "Enter name"
+        name <- getLine
+        -- Print at some point in any monadic function
+        traceM $ "user entered " ++ name
+        putStrLn $ "Hello " ++ name
+        -- Print a value before passing it on
+        greet $ traceShowId (n - 1)
+
+
+===========================================================================
+
+If you want to invoke `ghci` directly, such as on `shellcheck.hs`, to
+debug all of ShellCheck including I/O, you may see an error like this:
+
+    src/ShellCheck/Data.hs:5:1: error:
+        Could not load module ‘Paths_ShellCheck’
+    it is a hidden module in the package ‘ShellCheck-0.8.0’
+
+This can easily be circumvented by running `./setgitversion` or manually
+editing src/ShellCheck/Data.hs to replace the auto-deduced version number
+with a constant string as indicated.
+
+Afterwards, you can run the ShellCheck tool, as if from the shell, with:
+
+    $ ghci shellcheck.hs
+    ghci> runMain ["-x", "file.sh"]
+
+-}
+
+module ShellCheck.Debug () where
+
+import ShellCheck.Analyzer
+import ShellCheck.AST
+import ShellCheck.CFG
+import ShellCheck.Checker
+import ShellCheck.CFGAnalysis as CF
+import ShellCheck.Interface
+import ShellCheck.Parser
+import ShellCheck.Prelude
+
+import Control.Monad
+import Control.Monad.Identity
+import Control.Monad.RWS
+import Control.Monad.Writer
+import Data.Graph.Inductive.Graph as G
+import Data.List
+import Data.Maybe
+import qualified Data.Map as M
+import qualified Data.Set as S
+
+
+-- Run all of ShellCheck (minus output formatters)
+shellcheckString :: String -> CheckResult
+shellcheckString scriptString =
+    runIdentity $ checkScript dummySystemInterface checkSpec
+  where
+    checkSpec :: CheckSpec
+    checkSpec = emptyCheckSpec {
+        csScript = scriptString
+    }
+
+dummySystemInterface :: SystemInterface Identity
+dummySystemInterface = mockedSystemInterface [
+    -- A tiny, fake filesystem for sourced files
+    ("lib/mylib1.sh", "foo=$(cat $1 | wc -l)"),
+    ("lib/mylib2.sh", "bar=42")
+    ]
+
+-- Parameters used when generating Control Flow Graphs
+cfgParams :: CFGParameters
+cfgParams = CFGParameters {
+    cfLastpipe = False,
+    cfPipefail = False
+}
+
+-- An example script to play with
+exampleScript :: String
+exampleScript = unlines [
+    "#!/bin/sh",
+    "count=0",
+    "for file in *",
+    "do",
+    "  (( count++ ))",
+    "done",
+    "echo $count"
+    ]
+
+-- Parse the script string into ShellCheck's ParseResult
+parseScriptString :: String -> ParseResult
+parseScriptString scriptString =
+    runIdentity $ parseScript dummySystemInterface parseSpec
+  where
+    parseSpec :: ParseSpec
+    parseSpec = newParseSpec {
+        psFilename = "myscript",
+        psScript = scriptString
+    }
+
+
+-- Parse the script string into an Abstract Syntax Tree
+stringToAst :: String -> Token
+stringToAst scriptString =
+    case maybeRoot of
+        Just root -> root
+        Nothing -> error $ "Script failed to parse: " ++ show parserWarnings
+  where
+    parseResult :: ParseResult
+    parseResult = parseScriptString scriptString
+
+    maybeRoot :: Maybe Token
+    maybeRoot = prRoot parseResult
+
+    parserWarnings :: [PositionedComment]
+    parserWarnings = prComments parseResult
+
+
+astToCfgResult :: Token -> CFGResult
+astToCfgResult = buildGraph cfgParams
+
+astToDfa :: Token -> CFGAnalysis
+astToDfa = analyzeControlFlow cfgParams
+
+astToCfg :: Token -> CFGraph
+astToCfg = cfGraph . astToCfgResult
+
+stringToCfg :: String -> CFGraph
+stringToCfg = astToCfg . stringToAst
+
+stringToDfa :: String -> CFGAnalysis
+stringToDfa = astToDfa . stringToAst
+
+cfgToGraphViz :: CFGraph -> String
+cfgToGraphViz = cfgToGraphVizWith show
+
+stringToCfgViz :: String -> String
+stringToCfgViz = cfgToGraphViz . stringToCfg
+
+stringToDfaViz :: String -> String
+stringToDfaViz = dfaToGraphViz . stringToDfa
+
+-- Dump a Control Flow Graph as GraphViz with extended information
+stringToDetailedCfgViz :: String -> String
+stringToDetailedCfgViz scriptString = cfgToGraphVizWith nodeLabel graph
+  where
+    ast :: Token
+    ast = stringToAst scriptString
+
+    cfgResult :: CFGResult
+    cfgResult = astToCfgResult ast
+
+    graph :: CFGraph
+    graph = cfGraph cfgResult
+
+    idToToken :: M.Map Id Token
+    idToToken = M.fromList $ execWriter $ doAnalysis (\c -> tell [(getId c, c)]) ast
+
+    idToNode :: M.Map Id (Node, Node)
+    idToNode = cfIdToRange cfgResult
+
+    nodeToStartIds :: M.Map Node (S.Set Id)
+    nodeToStartIds =
+        M.fromListWith S.union $
+            map (\(id, (start, _)) -> (start, S.singleton id)) $
+                M.toList idToNode
+
+    nodeToEndIds :: M.Map Node (S.Set Id)
+    nodeToEndIds =
+        M.fromListWith S.union $
+            map (\(id, (_, end)) -> (end, S.singleton id)) $
+                M.toList idToNode
+
+    formatId :: Id -> String
+    formatId id = fromMaybe ("Unknown " ++ show id) $ do
+        (OuterToken _ token) <- M.lookup id idToToken
+        firstWord <- words (show token) !!! 0
+        -- Strip off "Inner_"
+        (_ : tokenName) <- return $ dropWhile (/= '_') firstWord
+        return $ tokenName ++ " " ++ show id
+
+    formatGroup :: S.Set Id -> String
+    formatGroup set = intercalate ", " $ map formatId $ S.toList set
+
+    nodeLabel (node, label) = unlines [
+        show node ++ ". " ++ show label,
+        "Begin: " ++ formatGroup (M.findWithDefault S.empty node nodeToStartIds),
+        "End: " ++ formatGroup (M.findWithDefault S.empty node nodeToEndIds)
+        ]
+
+
+-- Dump a Control Flow Graph with Data Flow Analysis as GraphViz
+dfaToGraphViz :: CF.CFGAnalysis -> String
+dfaToGraphViz analysis = cfgToGraphVizWith label $ CF.graph analysis
+  where
+    label (node, label) =
+        let
+            desc = show node ++ ". " ++ show label
+        in
+            fromMaybe ("No DFA available\n\n" ++ desc) $ do
+                (pre, post) <- M.lookup node $ CF.nodeToData analysis
+                return $ unlines [
+                    "Precondition: " ++ show pre,
+                    "",
+                    desc,
+                    "",
+                    "Postcondition: " ++ show post
+                    ]
+
+
+-- Dump an Control Flow Graph to GraphViz with a given node formatter
+cfgToGraphVizWith :: (LNode CFNode -> String) -> CFGraph -> String
+cfgToGraphVizWith nodeLabel graph = concat [
+    "digraph {\n",
+    concatMap dumpNode (labNodes graph),
+    concatMap dumpLink (labEdges graph),
+    tagVizEntries graph,
+    "}\n"
+    ]
+  where
+    dumpNode l@(node, label) = show node ++ " [label=" ++ quoteViz (nodeLabel l) ++ "]\n"
+    dumpLink (from, to, typ) = show from ++ " -> " ++ show to ++ " [style=" ++ quoteViz (edgeStyle typ)  ++ "]\n"
+    edgeStyle CFEFlow = "solid"
+    edgeStyle CFEExit = "bold"
+    edgeStyle CFEFalseFlow = "dotted"
+
+quoteViz str = "\"" ++ escapeViz str ++ "\""
+escapeViz [] = []
+escapeViz (c:rest) =
+    case c of
+        '\"' -> '\\' : '\"' : escapeViz rest
+        '\n' -> '\\' : 'l' : escapeViz rest
+        '\\' -> '\\' : '\\' : escapeViz rest
+        _ -> c : escapeViz rest
+
+
+-- Dump an Abstract Syntax Tree (or branch thereof) to GraphViz format
+astToGraphViz :: Token -> String
+astToGraphViz token = concat [
+    "digraph {\n",
+    formatTree token,
+    "}\n"
+    ]
+  where
+    formatTree :: Token -> String
+    formatTree t = snd $ execRWS (doStackAnalysis push pop t) () []
+
+    push :: Token -> RWS () String [Int] ()
+    push (OuterToken (Id n) inner) = do
+        stack <- get
+        put (n : stack)
+        case stack of
+            [] -> return ()
+            (top:_) -> tell $ show top ++ " -> " ++ show n ++ "\n"
+        tell $ show n ++ " [label=" ++ quoteViz (show n ++ ": " ++ take 32 (show inner)) ++ "]\n"
+
+    pop :: Token -> RWS () String [Int] ()
+    pop _ = modify tail
+
+
+-- For each entry point, set the rank so that they'll align in the graph
+tagVizEntries :: CFGraph -> String
+tagVizEntries graph = "{ rank=same " ++ rank ++ " }"
+  where
+    entries = mapMaybe find $ labNodes graph
+    find (node, CFEntryPoint name) = return (node, name)
+    find _ = Nothing
+    rank = unwords $ map (\(c, _) -> show c) entries

src/ShellCheck/Fixer.hs

@@ -22,6 +22,8 @@
 module ShellCheck.Fixer (applyFix, removeTabStops, mapPositions, Ranged(..), runTests) where
 
 import ShellCheck.Interface
+import ShellCheck.Prelude
+import Control.Monad
 import Control.Monad.State
 import Data.Array
 import Data.List
@@ -35,7 +37,7 @@ class Ranged a where
     end     :: a -> Position
     overlap :: a -> a -> Bool
     overlap x y =
-        (yStart >= xStart && yStart < xEnd) || (yStart < xStart && yEnd > xStart)
+        xEnd > yStart && yEnd > xStart
         where
             yStart = start y
             yEnd = end y
@@ -86,6 +88,7 @@ instance Ranged Replacement where
 instance Monoid Fix where
     mempty = newFix
     mappend = (<>)
+    mconcat = foldl mappend mempty -- fold left to right since <> discards right on overlap
 
 instance Semigroup Fix where
     f1 <> f2 =
@@ -228,7 +231,7 @@ applyReplacement2 rep string = do
 
     let (l1, l2) = tmap posLine originalPos in
         when (l1 /= 1 || l2 /= 1) $
-            error "ShellCheck internal error, please report: bad cross-line fix"
+            error $ pleaseReport "bad cross-line fix"
 
     let replacer = repString rep
     let shift = (length replacer) - (oldEnd - oldStart)

src/ShellCheck/Formatter/CheckStyle.hs

@@ -24,8 +24,8 @@ import ShellCheck.Formatter.Format
 
 import Data.Char
 import Data.List
-import GHC.Exts
 import System.IO
+import qualified Data.List.NonEmpty as NE
 
 format :: IO Formatter
 format = return Formatter {
@@ -45,12 +45,12 @@ outputResults cr sys =
     else mapM_ outputGroup fileGroups
   where
     comments = crComments cr
-    fileGroups = groupWith sourceFile comments
+    fileGroups = NE.groupWith sourceFile comments
     outputGroup group = do
-        let filename = sourceFile (head group)
+        let filename = sourceFile (NE.head group)
-        result <- (siReadFile sys) filename
+        result <- siReadFile sys (Just True) filename
         let contents = either (const "") id result
-        outputFile filename contents group
+        outputFile filename contents (NE.toList group)
 
 outputFile filename contents warnings = do
     let comments = makeNonVirtual warnings contents
@@ -88,7 +88,7 @@ outputError file error = putStrLn $ concat [
 attr s v = concat [ s, "='", escape v, "' " ]
 escape = concatMap escape'
 escape' c = if isOk c then [c] else "&#" ++ show (ord c) ++ ";"
-isOk x = any ($x) [isAsciiUpper, isAsciiLower, isDigit, (`elem` " ./")]
+isOk x = any ($ x) [isAsciiUpper, isAsciiLower, isDigit, (`elem` " ./")]
 
 severity "error" = "error"
 severity "warning" = "warning"

src/ShellCheck/Formatter/Diff.hs

@@ -38,9 +38,6 @@ import System.FilePath
 
 import Test.QuickCheck
 
-import Debug.Trace
-ltt x = trace (show x) x
-
 format :: FormatterOptions -> IO Formatter
 format options = do
     foundIssues <- newIORef False
@@ -90,7 +87,7 @@ reportResult foundIssues reportedIssues color result sys = do
     mapM_ output $ M.toList fixmap
   where
     output (name, fix) = do
-        file <- (siReadFile sys) name
+        file <- siReadFile sys (Just True) name
         case file of
             Right contents -> do
                 putStrLn $ formatDoc color $ makeDiff name contents fix
@@ -194,11 +191,17 @@ splitLast x =
     let (last, rest) = splitAt 1 $ reverse x
     in (reverse rest, last)
 
+-- git patch does not like `\` on Windows
+normalizePath path =
+    case path of
+        c:rest -> (if c == pathSeparator then '/' else c) : normalizePath rest
+        [] -> []
+
 formatDoc color (DiffDoc name lf regions) =
     let (most, last) = splitLast regions
     in
-          (color bold $ "--- " ++ ("a" </> name)) ++ "\n" ++
+          (color bold $ "--- " ++ (normalizePath $ "a" </> name)) ++ "\n" ++
-          (color bold $ "+++ " ++ ("b" </> name)) ++ "\n" ++
+          (color bold $ "+++ " ++ (normalizePath $ "b" </> name)) ++ "\n" ++
           concatMap (formatRegion color LinefeedOk) most ++
           concatMap (formatRegion color lf) last
 
@@ -206,10 +209,9 @@ formatDoc color (DiffDoc name lf regions) =
 buildFixMap :: [Fix] -> M.Map String Fix
 buildFixMap fixes = perFile
   where
-    splitFixes = concatMap splitFixByFile fixes
+    splitFixes = splitFixByFile $ mconcat fixes
     perFile = groupByMap (posFile . repStartPos . head . fixReplacements) splitFixes
 
--- There are currently no multi-file fixes, but let's handle it anyways
 splitFixByFile :: Fix -> [Fix]
 splitFixByFile fix = map makeFix $ groupBy sameFile (fixReplacements fix)
   where

src/ShellCheck/Formatter/Format.hs

@@ -28,6 +28,7 @@ import Data.Array
 import Data.List
 import System.IO
 import System.Info
+import System.Environment
 
 -- A formatter that carries along an arbitrary piece of data
 data Formatter = Formatter {
@@ -68,12 +69,14 @@ makeNonVirtual comments contents =
 
 
 shouldOutputColor :: ColorOption -> IO Bool
-shouldOutputColor colorOption = do
+shouldOutputColor colorOption =
-    term <- hIsTerminalDevice stdout
+    case colorOption of
-    let windows = "mingw" `isPrefixOf` os
+        ColorAlways -> return True
-    let isUsableTty = term && not windows
+        ColorNever -> return False
-    let useColor = case colorOption of
+        ColorAuto -> do
-                       ColorAlways -> True
+            isTerminal <- hIsTerminalDevice stdout
-                       ColorNever -> False
+            term <- lookupEnv "TERM"
-                       ColorAuto -> isUsableTty
+            let windows = "mingw" `isPrefixOf` os
-    return useColor
+            let dumbTerm = term `elem` [Just "dumb", Just "", Nothing]
+            let isUsableTty = isTerminal && not windows && not dumbTerm
+            return isUsableTty

src/ShellCheck/Formatter/GCC.hs

@@ -23,8 +23,8 @@ import ShellCheck.Interface
 import ShellCheck.Formatter.Format
 
 import Data.List
-import GHC.Exts
 import System.IO
+import qualified Data.List.NonEmpty as NE
 
 format :: IO Formatter
 format = return Formatter {
@@ -39,13 +39,13 @@ outputError file error = hPutStrLn stderr $ file ++ ": " ++ error
 outputAll cr sys = mapM_ f groups
   where
     comments = crComments cr
-    groups = groupWith sourceFile comments
+    groups = NE.groupWith sourceFile comments
-    f :: [PositionedComment] -> IO ()
+    f :: NE.NonEmpty PositionedComment -> IO ()
     f group = do
-        let filename = sourceFile (head group)
+        let filename = sourceFile (NE.head group)
-        result <- (siReadFile sys) filename
+        result <- siReadFile sys (Just True) filename
         let contents = either (const "") id result
-        outputResult filename contents group
+        outputResult filename contents (NE.toList group)
 
 outputResult filename contents warnings = do
     let comments = makeNonVirtual warnings contents

src/ShellCheck/Formatter/JSON.hs

@@ -23,6 +23,7 @@ module ShellCheck.Formatter.JSON (format) where
 import ShellCheck.Interface
 import ShellCheck.Formatter.Format
 
+import Control.DeepSeq
 import Data.Aeson
 import Data.IORef
 import Data.Monoid
@@ -103,7 +104,7 @@ collectResult ref cr sys = mapM_ f groups
     comments = crComments cr
     groups = groupWith sourceFile comments
     f :: [PositionedComment] -> IO ()
-    f group = modifyIORef ref (\x -> comments ++ x)
+    f group = deepseq comments $ modifyIORef ref (\x -> comments ++ x)
 
 finish ref = do
     list <- readIORef ref

src/ShellCheck/Formatter/JSON1.hs

@@ -23,12 +23,13 @@ module ShellCheck.Formatter.JSON1 (format) where
 import ShellCheck.Interface
 import ShellCheck.Formatter.Format
 
+import Control.DeepSeq
 import Data.Aeson
 import Data.IORef
 import Data.Monoid
-import GHC.Exts
 import System.IO
 import qualified Data.ByteString.Lazy.Char8 as BL
+import qualified Data.List.NonEmpty as NE
 
 format :: IO Formatter
 format = do
@@ -113,14 +114,14 @@ outputError file msg = hPutStrLn stderr $ file ++ ": " ++ msg
 collectResult ref cr sys = mapM_ f groups
   where
     comments = crComments cr
-    groups = groupWith sourceFile comments
+    groups = NE.groupWith sourceFile comments
-    f :: [PositionedComment] -> IO ()
+    f :: NE.NonEmpty PositionedComment -> IO ()
     f group = do
-        let filename = sourceFile (head group)
+        let filename = sourceFile (NE.head group)
-        result <- siReadFile sys filename
+        result <- siReadFile sys (Just True) filename
         let contents = either (const "") id result
         let comments' = makeNonVirtual comments contents
-        modifyIORef ref (\x -> comments' ++ x)
+        deepseq comments' $ modifyIORef ref (\x -> comments' ++ x)
 
 finish ref = do
     list <- readIORef ref

src/ShellCheck/Formatter/TTY.hs

@@ -23,6 +23,7 @@ import ShellCheck.Fixer
 import ShellCheck.Interface
 import ShellCheck.Formatter.Format
 
+import Control.DeepSeq
 import Control.Monad
 import Data.Array
 import Data.Foldable
@@ -30,9 +31,9 @@ import Data.Ord
 import Data.IORef
 import Data.List
 import Data.Maybe
-import GHC.Exts
 import System.IO
 import System.Info
+import qualified Data.List.NonEmpty as NE
 
 wikiLink = "https://www.shellcheck.net/wiki/"
 
@@ -88,7 +89,7 @@ rankError err = (ranking, cSeverity $ pcComment err, cCode $ pcComment err)
 appendComments errRef comments max = do
     previous <- readIORef errRef
     let current = map (\x -> (rankError x, cCode $ pcComment x, cMessage $ pcComment x)) comments
-    writeIORef errRef . take max . nubBy equal . sort $ previous ++ current
+    writeIORef errRef $! force . take max . nubBy equal . sort $ previous ++ current
   where
     fst3 (x,_,_) = x
     equal x y = fst3 x == fst3 y
@@ -116,19 +117,19 @@ outputResult options ref result sys = do
     color <- getColorFunc $ foColorOption options
     let comments = crComments result
     appendComments ref comments (fromIntegral $ foWikiLinkCount options)
-    let fileGroups = groupWith sourceFile comments
+    let fileGroups = NE.groupWith sourceFile comments
     mapM_ (outputForFile color sys) fileGroups
 
 outputForFile color sys comments = do
-    let fileName = sourceFile (head comments)
+    let fileName = sourceFile (NE.head comments)
-    result <- (siReadFile sys) fileName
+    result <- siReadFile sys (Just True) fileName
     let contents = either (const "") id result
     let fileLinesList = lines contents
     let lineCount = length fileLinesList
     let fileLines = listArray (1, lineCount) fileLinesList
-    let groups = groupWith lineNo comments
+    let groups = NE.groupWith lineNo comments
     forM_ groups $ \commentsForLine -> do
-        let lineNum = fromIntegral $ lineNo (head commentsForLine)
+        let lineNum = fromIntegral $ lineNo (NE.head commentsForLine)
         let line = if lineNum < 1 || lineNum > lineCount
                         then ""
                         else fileLines ! fromIntegral lineNum
@@ -138,7 +139,7 @@ outputForFile color sys comments = do
         putStrLn (color "source" line)
         forM_ commentsForLine $ \c -> putStrLn $ color (severityText c) $ cuteIndent c
         putStrLn ""
-        showFixedString color commentsForLine (fromIntegral lineNum) fileLines
+        showFixedString color (toList commentsForLine) (fromIntegral lineNum) fileLines
 
 -- Pick out only the lines necessary to show a fix in action
 sliceFile :: Fix -> Array Int String -> (Fix, Array Int String)
@@ -168,13 +169,13 @@ showFixedString color comments lineNum fileLines =
             -- and/or other unrelated lines.
             let (excerptFix, excerpt) = sliceFile mergedFix fileLines
             -- in the spirit of error prone
-            putStrLn $ color "message" "Did you mean: "
+            putStrLn $ color "message" "Did you mean:"
             putStrLn $ unlines $ applyFix excerptFix excerpt
 
 cuteIndent :: PositionedComment -> String
 cuteIndent comment =
     replicate (fromIntegral $ colNo comment - 1) ' ' ++
-        makeArrow ++ " " ++ code (codeNo comment) ++ ": " ++ messageText comment
+        makeArrow ++ " " ++ code (codeNo comment) ++ " (" ++ severityText comment ++ "): " ++ messageText comment
   where
     arrow n = '^' : replicate (fromIntegral $ n-2) '-' ++ "^"
     makeArrow =

src/ShellCheck/Interface.hs

@@ -1,5 +1,5 @@
 {-
-    Copyright 2012-2019 Vidar Holen
+    Copyright 2012-2024 Vidar Holen
 
     This file is part of ShellCheck.
     https://www.shellcheck.net
@@ -21,14 +21,14 @@
 module ShellCheck.Interface
     (
     SystemInterface(..)
-    , CheckSpec(csFilename, csScript, csCheckSourced, csIncludedWarnings, csExcludedWarnings, csShellTypeOverride, csMinSeverity, csIgnoreRC, csOptionalChecks)
+    , CheckSpec(csFilename, csScript, csCheckSourced, csIncludedWarnings, csExcludedWarnings, csShellTypeOverride, csMinSeverity, csIgnoreRC, csExtendedAnalysis, csOptionalChecks)
     , CheckResult(crFilename, crComments)
     , ParseSpec(psFilename, psScript, psCheckSourced, psIgnoreRC, psShellTypeOverride)
     , ParseResult(prComments, prTokenPositions, prRoot)
-    , AnalysisSpec(asScript, asShellType, asFallbackShell, asExecutionMode, asCheckSourced, asTokenPositions, asOptionalChecks)
+    , AnalysisSpec(asScript, asShellType, asFallbackShell, asExecutionMode, asCheckSourced, asTokenPositions, asExtendedAnalysis, asOptionalChecks)
     , AnalysisResult(arComments)
     , FormatterOptions(foColorOption, foWikiLinkCount)
-    , Shell(Ksh, Sh, Bash, Dash)
+    , Shell(Ksh, Sh, Bash, Dash, BusyboxSh)
     , ExecutionMode(Executed, Sourced)
     , ErrorMessage
     , Code
@@ -39,11 +39,12 @@ module ShellCheck.Interface
     , ColorOption(ColorAuto, ColorAlways, ColorNever)
     , TokenComment(tcId, tcComment, tcFix)
     , emptyCheckResult
-    , newParseResult
-    , newAnalysisSpec
     , newAnalysisResult
+    , newAnalysisSpec
     , newFormatterOptions
+    , newParseResult
     , newPosition
+    , newSystemInterface
     , newTokenComment
     , mockedSystemInterface
     , mockRcFile
@@ -73,15 +74,19 @@ import qualified Data.Map as Map
 
 
 data SystemInterface m = SystemInterface {
-    -- Read a file by filename, or return an error
+    -- | Given:
-    siReadFile :: String -> m (Either ErrorMessage String),
+    --   What annotations say about including external files (if anything)
-    -- Given:
+    --   A resolved filename from siFindSource
+    --   Read the file or return an error
+    siReadFile :: Maybe Bool -> String -> m (Either ErrorMessage String),
+    -- | Given:
     --   the current script,
+    --   what annotations say about including external files (if anything)
     --   a list of source-path annotations in effect,
     --   and a sourced file,
     --   find the sourced file
-    siFindSource :: String -> [String] -> String -> m FilePath,
+    siFindSource :: String -> Maybe Bool -> [String] -> String -> m FilePath,
-    -- Get the configuration file (name, contents) for a filename
+    -- | Get the configuration file (name, contents) for a filename
     siGetConfig :: String -> m (Maybe (FilePath, String))
 }
 
@@ -95,6 +100,7 @@ data CheckSpec = CheckSpec {
     csIncludedWarnings :: Maybe [Integer],
     csShellTypeOverride :: Maybe Shell,
     csMinSeverity :: Severity,
+    csExtendedAnalysis :: Maybe Bool,
     csOptionalChecks :: [String]
 } deriving (Show, Eq)
 
@@ -119,6 +125,7 @@ emptyCheckSpec = CheckSpec {
     csIncludedWarnings = Nothing,
     csShellTypeOverride = Nothing,
     csMinSeverity = StyleC,
+    csExtendedAnalysis = Nothing,
     csOptionalChecks = []
 }
 
@@ -131,6 +138,14 @@ newParseSpec = ParseSpec {
     psShellTypeOverride = Nothing
 }
 
+newSystemInterface :: Monad m => SystemInterface m
+newSystemInterface =
+    SystemInterface {
+        siReadFile = \_ _ -> return $ Left "Not implemented",
+        siFindSource = \_ _ _ name -> return name,
+        siGetConfig = \_ -> return Nothing
+    }
+
 -- Parser input and output
 data ParseSpec = ParseSpec {
     psFilename :: String,
@@ -161,6 +176,7 @@ data AnalysisSpec = AnalysisSpec {
     asExecutionMode :: ExecutionMode,
     asCheckSourced :: Bool,
     asOptionalChecks :: [String],
+    asExtendedAnalysis :: Maybe Bool,
     asTokenPositions :: Map.Map Id (Position, Position)
 }
 
@@ -171,6 +187,7 @@ newAnalysisSpec token = AnalysisSpec {
     asExecutionMode = Executed,
     asCheckSourced = False,
     asOptionalChecks = [],
+    asExtendedAnalysis = Nothing,
     asTokenPositions = Map.empty
 }
 
@@ -208,7 +225,7 @@ newCheckDescription = CheckDescription {
     }
 
 -- Supporting data types
-data Shell = Ksh | Sh | Bash | Dash deriving (Show, Eq)
+data Shell = Ksh | Sh | Bash | Dash | BusyboxSh deriving (Show, Eq)
 data ExecutionMode = Executed | Sourced deriving (Show, Eq)
 
 type ErrorMessage = String
@@ -307,19 +324,18 @@ data ColorOption =
 
 -- For testing
 mockedSystemInterface :: [(String, String)] -> SystemInterface Identity
-mockedSystemInterface files = SystemInterface {
+mockedSystemInterface files = (newSystemInterface :: SystemInterface Identity) {
     siReadFile = rf,
     siFindSource = fs,
     siGetConfig = const $ return Nothing
 }
   where
-    rf file = return $
+    rf _ file = return $
         case find ((== file) . fst) files of
             Nothing -> Left "File not included in mock."
             Just (_, contents) -> Right contents
-    fs _ _ file = return file
+    fs _ _ _ file = return file
 
 mockRcFile rcfile mock = mock {
     siGetConfig = const . return $ Just (".shellcheckrc", rcfile)
 }
-

src/ShellCheck/Prelude.hs

@@ -0,0 +1,51 @@
+{-
+    Copyright 2022 Vidar Holen
+
+    This file is part of ShellCheck.
+    https://www.shellcheck.net
+
+    ShellCheck is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    ShellCheck is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+-}
+
+-- Generic basic utility functions
+module ShellCheck.Prelude where
+
+import Data.Semigroup
+
+
+-- Get element 0 or a default. Like `head` but safe.
+headOrDefault _ (a:_) = a
+headOrDefault def _   = def
+
+-- Get the last element or a default. Like `last` but safe.
+lastOrDefault def [] = def
+lastOrDefault _ list = last list
+
+--- Get element n of a list, or Nothing. Like `!!` but safe.
+(!!!) list i =
+    case drop i list of
+        []    -> Nothing
+        (r:_) -> Just r
+
+
+-- Like mconcat but for Semigroups
+sconcat1 :: (Semigroup t) => [t] -> t
+sconcat1 [x] = x
+sconcat1 (x:xs) = x <> sconcat1 xs
+
+sconcatOrDefault def [] = def
+sconcatOrDefault _ list = sconcat1 list
+
+-- For more actionable "impossible" errors
+pleaseReport str = "ShellCheck internal error, please report: " ++ str

stack.yaml

@@ -2,7 +2,7 @@
 # For more information, see: https://docs.haskellstack.org/en/stable/yaml_configuration/
 
 # Specifies the GHC version and set of packages available (e.g., lts-3.5, nightly-2015-09-21, ghc-7.10.2)
-resolver: lts-13.26
+resolver: lts-18.15
 
 # Local packages, usually specified by relative directory name
 packages:

striptests

@@ -29,6 +29,7 @@ detestify() {
       state = 0;
     }
 
+    /STRIP/ { next; }
     /LANGUAGE TemplateHaskell/ { next; }
     /^import.*Test\./ { next; }
 
@@ -75,4 +76,3 @@ find . -name '.git' -prune -o -type f -name '*.hs' -print |
   do
     modify "$file" detestify
   done
-

test/buildtest

@@ -12,6 +12,12 @@ command -v cabal ||
 cabal update ||
   die "can't update"
 
+if [ -e "cabal.project.freeze" ]
+then
+  echo "Renaming cabal.project.freeze to .bak to avoid it interferring" >&2
+  mv "cabal.project.freeze" "cabal.project.freeze.bak" || die "Couldn't rename"
+fi
+
 if [ -e /etc/arch-release ]
 then
   # Arch has an unconventional packaging setup
@@ -22,13 +28,16 @@ fi
 
 cabal install --dependencies-only --enable-tests "${flags[@]}" ||
   cabal install --dependencies-only "${flags[@]}" ||
-    die "can't install dependencies"
+    cabal install --dependencies-only --max-backjumps -1 "${flags[@]}" ||
+      die "can't install dependencies"
 cabal configure --enable-tests "${flags[@]}" ||
   die "configure failed"
 cabal build ||
   die "build failed"
 cabal test ||
   die "test failed"
+cabal haddock ||
+  die "haddock failed"
 
 sc="$(find . -name shellcheck -type f -perm -111)"
 [ -x "$sc" ] || die "Can't find executable"

test/check_release

@@ -7,11 +7,60 @@ fail() {
   failed=1
 }
 
+i=1 j=1
+cat << EOF
+
+Manual Checklist
+
+$((i++)). Make sure README.md examples are up to date
+$((i++)). Format and read over the manual for bad formatting and outdated info.
+$((i++)). Run \`builders/build_builder build/*/\` to update all builder images.
+$((i++)). \`builders/run_builder dist-newstyle/sdist/ShellCheck-*.tar.gz builders/*/\` to verify that they work.
+$((i++)). \`for f in \$(cat build/*/tag); do docker push "\$f"; done\` to upload them.
+$((i++)). Run test/distrotest to ensure that most distros can build OOTB.
+$((i++)). Make sure GitHub Build currently passes: https://github.com/koalaman/shellcheck/actions
+$((i++)). Make sure SnapCraft build currently works: https://snapcraft.io/shellcheck/builds
+$((i++)). Make sure the Hackage package builds locally.
+$((i++)). Make sure none of the automated checks below fail
+
+Release Steps
+
+$((j++)). \`cabal sdist\` to generate a Hackage package
+$((j++)). \`git push --follow-tags\` to push commit
+$((j++)). Wait for GitHub Actions to build. (v0.11.0 "Deploy" failed, but worked on retry)
+$((j++)). Verify release:
+  a. Check that the new versions are uploaded: https://github.com/koalaman/shellcheck/tags
+  b. Check that the docker images have version tags: https://hub.docker.com/u/koalaman
+$((j++)). If no disaster, upload to Hackage: http://hackage.haskell.org/upload
+$((j++)). Run 'autoupdate' from https://github.com/koalaman/shellcheck-precommit
+$((j++)). Release new snap versions on https://snapcraft.io/shellcheck/releases
+$((j++)). Push a new commit that updates CHANGELOG.md
+
+Automated Checks
+
+EOF
+
 if git diff | grep -q ""
 then
   fail "There are uncommitted changes"
 fi
 
+if [[ $(git log -1 --pretty=%B) != *"CHANGELOG"* ]]
+then
+  fail "Expected git log message to contain CHANGELOG"
+fi
+
+version=${current#v}
+if ! grep "Version:" ShellCheck.cabal | grep -qFw "$version"
+then
+  fail "The cabal file does not match tag version $version"
+fi
+
+if ! grep -qF "## $current" CHANGELOG.md
+then
+  fail "CHANGELOG.md does not contain '## $current'"
+fi
+
 current=$(git tag --points-at)
 if [[ -z "$current" ]]
 then
@@ -34,43 +83,8 @@ then
   fail "You are not on master"
 fi
 
-version=${current#v}
-if ! grep "Version:" ShellCheck.cabal | grep -qFw "$version"
-then
-  fail "The cabal file does not match tag version $version"
-fi
-
-if ! grep -qF "## $current" CHANGELOG.md
-then
-  fail "CHANGELOG.md does not contain '## $current'"
-fi
-
 if [[ $(git log -1 --pretty=%B) != "Stable version "* ]]
 then
   fail "Expected git log message to be 'Stable version ...'"
 fi
-
-i=1 j=1
-cat << EOF
-
-Manual Checklist
-
-$((i++)). Make sure none of the automated checks above failed
-$((i++)). Make sure Travis build currently passes: https://travis-ci.org/koalaman/shellcheck
-$((i++)). Make sure SnapCraft build currently works: https://build.snapcraft.io/user/koalaman
-$((i++)). Run test/distrotest to ensure that most distros can build OOTB.
-$((i++)). Format and read over the manual for bad formatting and outdated info.
-$((i++)). Make sure the Hackage package builds, so that all files are 
-
-Release Steps
-
-$((j++)). \`cabal sdist\` to generate a Hackage package
-$((j++)). \`git push --follow-tags\` to push commit
-$((j++)). Wait for Travis to build
-$((j++)). Verify release:
-  a. Check that the new versions are uploaded: https://shellcheck.storage.googleapis.com/index.html
-  b. Check that the docker images have version tags: https://hub.docker.com/u/koalaman
-$((j++)). If no disaster, upload to Hackage: http://hackage.haskell.org/upload
-$((j++)). Push a new commit that updates CHANGELOG.md
-EOF
 exit "$failed"

test/distrotest

@@ -8,6 +8,15 @@ die() { echo "$*" >&4; exit 1; }
 
 [ -e "ShellCheck.cabal" ] || die "ShellCheck.cabal not in this dir"
 
+if ( snap list | grep -q docker ) > /dev/null 2>&1
+then
+  # Snap docker can't mount /tmp in containers
+  echo "You appear to be using Docker from snap. Creating ~/tmp for temp files." >&2
+  echo >&2
+  export TMPDIR="$HOME/tmp"
+  mkdir -p "$TMPDIR"
+fi
+
 [ "$1" = "--run" ] || {
 cat << EOF
 This script pulls multiple distros via Docker and compiles
@@ -17,13 +26,20 @@ and is still highly experimental.
 Make sure you're plugged in and have screen/tmux in place,
 then re-run with $0 --run to continue.
 
-Also note that dist* will be deleted.
+Also note that dist*/ and .stack-work/ will be deleted.
 EOF
 exit 0
 }
 
-echo "Deleting 'dist' and 'dist-newstyle'..."
+echo "Deleting 'dist', 'dist-newstyle', and '.stack-work'..."
-rm -rf dist dist-newstyle
+rm -rf dist dist-newstyle .stack-work
+
+execs=$(find . -name shellcheck)
+
+if [ -n "$execs" ]
+then
+  die "Found unexpected executables. Remove and try again: $execs"
+fi
 
 log=$(mktemp) || die "Can't create temp file"
 date >> "$log" || die "Can't write to log"
@@ -63,14 +79,16 @@ debian:testing        apt-get update && apt-get install -y cabal-install
 ubuntu:latest         apt-get update && apt-get install -y cabal-install
 haskell:latest        true
 opensuse/leap:latest  zypper install -y cabal-install ghc
-fedora:latest         dnf install -y cabal-install ghc-template-haskell-devel findutils
+fedora:latest         dnf install -y cabal-install ghc-template-haskell-devel findutils libstdc++-static gcc-c++
-archlinux/base:latest pacman -S -y --noconfirm cabal-install ghc-static base-devel
+archlinux:latest      pacman -S -y --noconfirm cabal-install ghc-static base-devel
 
-# Other versions we want to support
+# Ubuntu LTS
-ubuntu:18.04          apt-get update && apt-get install -y cabal-install
+ubuntu:24.04          apt-get update && apt-get install -y cabal-install
+ubuntu:22.04          apt-get update && apt-get install -y cabal-install
+ubuntu:20.04          apt-get update && apt-get install -y cabal-install
 
-# Misc Haskell including current and latest Stack build
+# Stack on Ubuntu LTS
-ubuntu:18.04          set -e; apt-get update && apt-get install -y curl && curl -sSL https://get.haskellstack.org/ | sh -s - -f && cd /mnt && exec test/stacktest
+ubuntu:24.04          set -e; apt-get update && apt-get install -y curl && curl -sSL https://get.haskellstack.org/ | sh -s - -f && cd /mnt && exec test/stacktest
 EOF
 
 exit "$final"

test/shellcheck.hs

@@ -4,8 +4,12 @@ import Control.Monad
 import System.Exit
 import qualified ShellCheck.Analytics
 import qualified ShellCheck.AnalyzerLib
+import qualified ShellCheck.ASTLib
+import qualified ShellCheck.CFG
+import qualified ShellCheck.CFGAnalysis
 import qualified ShellCheck.Checker
 import qualified ShellCheck.Checks.Commands
+import qualified ShellCheck.Checks.ControlFlow
 import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
 import qualified ShellCheck.Fixer
@@ -14,17 +18,24 @@ import qualified ShellCheck.Parser
 
 main = do
     putStrLn "Running ShellCheck tests..."
-    results <- sequence [
+    failures <- filter (not . snd) <$> mapM sequenceA tests
-        ShellCheck.Analytics.runTests
+    if null failures then exitSuccess else do
-        ,ShellCheck.AnalyzerLib.runTests
+      putStrLn "Tests failed for the following module(s):"
-        ,ShellCheck.Checker.runTests
+      mapM (putStrLn . ("- ShellCheck." ++) . fst) failures
-        ,ShellCheck.Checks.Commands.runTests
+      exitFailure
-        ,ShellCheck.Checks.Custom.runTests
+  where
-        ,ShellCheck.Checks.ShellSupport.runTests
+    tests =
-        ,ShellCheck.Fixer.runTests
+      [ ("Analytics"          , ShellCheck.Analytics.runTests)
-        ,ShellCheck.Formatter.Diff.runTests
+      , ("AnalyzerLib"        , ShellCheck.AnalyzerLib.runTests)
-        ,ShellCheck.Parser.runTests
+      , ("ASTLib"             , ShellCheck.ASTLib.runTests)
+      , ("CFG"                , ShellCheck.CFG.runTests)
+      , ("CFGAnalysis"        , ShellCheck.CFGAnalysis.runTests)
+      , ("Checker"            , ShellCheck.Checker.runTests)
+      , ("Checks.Commands"    , ShellCheck.Checks.Commands.runTests)
+      , ("Checks.ControlFlow" , ShellCheck.Checks.ControlFlow.runTests)
+      , ("Checks.Custom"      , ShellCheck.Checks.Custom.runTests)
+      , ("Checks.ShellSupport", ShellCheck.Checks.ShellSupport.runTests)
+      , ("Fixer"              , ShellCheck.Fixer.runTests)
+      , ("Formatter.Diff"     , ShellCheck.Formatter.Diff.runTests)
+      , ("Parser"             , ShellCheck.Parser.runTests)
       ]
-    if and results
-      then exitSuccess
-      else exitFailure

test/stacktest

@@ -3,7 +3,7 @@
 # various resolvers. It's run via distrotest.
 
 resolvers=(
-  nightly-"$(date -d "3 days ago" +"%Y-%m-%d")"
+#  nightly-"$(date -d "3 days ago" +"%Y-%m-%d")"
 )
 
 die() { echo "$*" >&2; exit 1; }
@@ -15,13 +15,14 @@ die() { echo "$*" >&2; exit 1; }
 command -v stack ||
   die "stack is missing"
 
-stack setup        || die "Failed to setup with default resolver"
+stack setup --allow-different-user || die "Failed to setup with default resolver"
 stack build --test || die "Failed to build/test with default resolver"
 
+# Nice to haves, but not necessary
 for resolver in "${resolvers[@]}"
 do
-  stack --resolver="$resolver" setup        || die "Failed to setup $resolver"
+  stack --resolver="$resolver" setup        || die "Failed to setup $resolver. This probably doesn't matter."
-  stack --resolver="$resolver" build --test || die "Failed build/test with $resolver!"
+  stack --resolver="$resolver" build --test || die "Failed build/test with $resolver! This probably doesn't matter."
 done
 
 echo "Success"