Stable version 0.4.4

This release is dedicated to AlphaGo,
embodying the second golden age of AI.

.ghci

@@ -0,0 +1 @@
+:set -idist/build/autogen

.gitignore

@@ -12,4 +12,4 @@ cabal-dev
 .cabal-sandbox/
 cabal.sandbox.config
 cabal.config
-
+.stack-work

LICENSE

@@ -1,5 +1,5 @@
-                    GNU AFFERO GENERAL PUBLIC LICENSE
-                       Version 3, 19 November 2007
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
 
  Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
  Everyone is permitted to copy and distribute verbatim copies
@@ -7,15 +7,17 @@
 
                             Preamble
 
-  The GNU Affero General Public License is a free, copyleft license for
-software and other kinds of works, specifically designed to ensure
-cooperation with the community in the case of network server software.
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
 
   The licenses for most software and other practical works are designed
 to take away your freedom to share and change the works.  By contrast,
-our General Public Licenses are intended to guarantee your freedom to
+the GNU General Public License is intended to guarantee your freedom to
 share and change all versions of a program--to make sure it remains free
-software for all its users.
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
 
   When we speak of free software, we are referring to freedom, not
 price.  Our General Public Licenses are designed to make sure that you
@@ -24,34 +26,44 @@ them if you wish), that you receive source code or can get it if you
 want it, that you can change the software or use pieces of it in new
 free programs, and that you know you can do these things.
 
-  Developers that use our General Public Licenses protect your rights
-with two steps: (1) assert copyright on the software, and (2) offer
-you this License which gives you legal permission to copy, distribute
-and/or modify the software.
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
 
-  A secondary benefit of defending all users' freedom is that
-improvements made in alternate versions of the program, if they
-receive widespread use, become available for other developers to
-incorporate.  Many developers of free software are heartened and
-encouraged by the resulting cooperation.  However, in the case of
-software used on network servers, this result may fail to come about.
-The GNU General Public License permits making a modified version and
-letting the public access it on a server without ever releasing its
-source code to the public.
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
 
-  The GNU Affero General Public License is designed specifically to
-ensure that, in such cases, the modified source code becomes available
-to the community.  It requires the operator of a network server to
-provide the source code of the modified version running there to the
-users of that server.  Therefore, public use of a modified version, on
-a publicly accessible server, gives the public access to the source
-code of the modified version.
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
 
-  An older license, called the Affero General Public License and
-published by Affero, was designed to accomplish similar goals.  This is
-a different license, not a version of the Affero GPL, but Affero has
-released a new version of the Affero GPL which permits relicensing under
-this license.
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so.  This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software.  The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable.  Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products.  If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+  Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary.  To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
 
   The precise terms and conditions for copying, distribution and
 modification follow.
@@ -60,7 +72,7 @@ modification follow.
 
   0. Definitions.
 
-  "This License" refers to version 3 of the GNU Affero General Public License.
+  "This License" refers to version 3 of the GNU General Public License.
 
   "Copyright" also means copyright-like laws that apply to other kinds of
 works, such as semiconductor masks.
@@ -537,45 +549,35 @@ to collect a royalty for further conveying from those to whom you convey
 the Program, the only way you could satisfy both those terms and this
 License would be to refrain entirely from conveying the Program.
 
-  13. Remote Network Interaction; Use with the GNU General Public License.
-
-  Notwithstanding any other provision of this License, if you modify the
-Program, your modified version must prominently offer all users
-interacting with it remotely through a computer network (if your version
-supports such interaction) an opportunity to receive the Corresponding
-Source of your version by providing access to the Corresponding Source
-from a network server at no charge, through some standard or customary
-means of facilitating copying of software.  This Corresponding Source
-shall include the Corresponding Source for any work covered by version 3
-of the GNU General Public License that is incorporated pursuant to the
-following paragraph.
+  13. Use with the GNU Affero General Public License.
 
   Notwithstanding any other provision of this License, you have
 permission to link or combine any covered work with a work licensed
-under version 3 of the GNU General Public License into a single
+under version 3 of the GNU Affero General Public License into a single
 combined work, and to convey the resulting work.  The terms of this
 License will continue to apply to the part which is the covered work,
-but the work with which it is combined will remain governed by version
-3 of the GNU General Public License.
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
 
   14. Revised Versions of this License.
 
   The Free Software Foundation may publish revised and/or new versions of
-the GNU Affero General Public License from time to time.  Such new versions
-will be similar in spirit to the present version, but may differ in detail to
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
 
   Each version is given a distinguishing version number.  If the
-Program specifies that a certain numbered version of the GNU Affero General
+Program specifies that a certain numbered version of the GNU General
 Public License "or any later version" applies to it, you have the
 option of following the terms and conditions either of that numbered
 version or of any later version published by the Free Software
 Foundation.  If the Program does not specify a version number of the
-GNU Affero General Public License, you may choose any version ever published
+GNU General Public License, you may choose any version ever published
 by the Free Software Foundation.
 
   If the Program specifies that a proxy can decide which future
-versions of the GNU Affero General Public License can be used, that proxy's
+versions of the GNU General Public License can be used, that proxy's
 public statement of acceptance of a version permanently authorizes you
 to choose that version for the Program.
 
@@ -633,29 +635,40 @@ the "copyright" line and a pointer to where the full notice is found.
     Copyright (C) <year>  <name of author>
 
     This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
+    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.
 
     This program 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 Affero General Public License for more details.
+    GNU General Public License for more details.
 
-    You should have received a copy of the GNU Affero General Public License
+    You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 Also add information on how to contact you by electronic and paper mail.
 
-  If your software can interact with users remotely through a computer
-network, you should also make sure that it provides a way for users to
-get its source.  For example, if your program is a web application, its
-interface could display a "Source" link that leads users to an archive
-of the code.  There are many ways you could offer source, and different
-solutions will be better for different programs; see section 13 for the
-specific requirements.
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
 
   You should also get your employer (if you work as a programmer) or school,
 if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU AGPL, see
+For more information on this, and how to apply and follow the GNU GPL, see
 <http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+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
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.

README.md

@@ -1,26 +1,67 @@
 # ShellCheck - A shell script static analysis tool
 
-http://www.shellcheck.net
+ShellCheck is a GPLv3 tool that gives warnings and suggestions for bash/sh shell scripts:
 
-Copyright 2012-2014, Vidar 'koala_man' Holen
-Licensed under the GNU Affero General Public License, v3
+![Screenshot of a terminal showing problematic shell script lines highlighted](doc/terminal.png).
 
-The goals of ShellCheck are:
+The goals of ShellCheck are
 
-  - To point out and clarify typical beginner's syntax issues,
-    that causes a shell to give cryptic error messages.
+  - To point out and clarify typical beginner's syntax issues
+    that cause a shell to give cryptic error messages.
 
-  - To point out and clarify typical intermediate level semantic problems,
-    that causes a shell to behave strangely and counter-intuitively.
+  - To point out and clarify typical intermediate level semantic problems
+    that cause a shell to behave strangely and counter-intuitively.
 
-  - To point out subtle caveats, corner cases and pitfalls, that may cause an
+  - To point out subtle caveats, corner cases and pitfalls that may cause an
     advanced user's otherwise working script to fail under future circumstances.
 
-ShellCheck is written in Haskell, and requires 2 GB of memory to compile.
+See [the gallery of bad code](README.md#user-content-gallery-of-bad-code) for examples of what ShellCheck can help you identify!
+
+
+## How to use
+There are a variety of ways to use ShellCheck!
+
+
+#### On the web
+Paste a shell script on http://www.shellcheck.net for instant feedback.
+
+[ShellCheck.net](http://www.shellcheck.net) is always synchronized to the latest git commit, and is the simplest way to give ShellCheck a go. Tell your friends!
+
+
+#### From your terminal
+Run `shellcheck yourscript` in your terminal for instant output, as seen above.
+
+
+#### In your editor
+
+You can see ShellCheck suggestions directly in a variety of editors.
+
+* Vim, through [Syntastic](https://github.com/scrooloose/syntastic):
+
+![Screenshot of vim showing inlined shellcheck feedback](doc/vim-syntastic.png).
+
+* Emacs, through [Flycheck](https://github.com/flycheck/flycheck):
+
+![Screenshot of emacs showing inlined shellcheck feedback](doc/emacs-flycheck.png).
+
+* Sublime, through [SublimeLinter](https://github.com/SublimeLinter/SublimeLinter-shellcheck).
+
+* Atom, through [Linter](https://github.com/AtomLinter/linter-shellcheck).
+
+* Most other editors, through [GCC error compatibility](shellcheck.1.md#user-content-formats).
+
+
+#### In your build or test suites
+While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites.
+
+Use ShellCheck's exit code, or its [CheckStyle compatible XML output](shellcheck.1.md#user-content-formats). There's also a simple JSON output format for easy integration.
+
 
 ## Installing
 
-On systems with Cabal:
+The easiest way to install ShellCheck locally is through your package manager.
+
+On systems with Cabal (installs to `~/.cabal/bin`):
 
     cabal update
     cabal install shellcheck
@@ -29,60 +70,245 @@ On Debian based distros:
 
     apt-get install shellcheck
 
+On Fedora based distros:
+
+    dnf install ShellCheck
+
 On OS X with homebrew:
 
     brew install shellcheck
 
-ShellCheck is also available as an online service:
+On OS X with MacPorts:
 
-    http://www.shellcheck.net
+    port install shellcheck
 
-## Building with Cabal
+On openSUSE:Tumbleweed:
 
-This sections describes how to build ShellCheck from a source directory.
+    zypper in ShellCheck
 
-First, make sure cabal is installed. On Debian based distros:
+On other openSUSE distributions:
 
-    apt-get install cabal-install
+add OBS devel:languages:haskell repository from https://build.opensuse.org/project/repositories/devel:languages:haskell
 
-On Fedora:
+    zypper ar http://download.opensuse.org/repositories/devel:/languages:/haskell/openSUSE_$(version)/devel:languages:haskell.repo
+    zypper in ShellCheck
 
-    yum install cabal-install
+or use OneClickInstall - https://software.opensuse.org/package/ShellCheck
 
-On Mac OS X with homebrew (http://brew.sh/):
 
-    brew install cabal-install
+## Compiling from source
 
-On Mac OS X with MacPorts (http://www.macports.org/):
+This section describes how to build ShellCheck from a source directory. ShellCheck is written in Haskell and requires 2GB of RAM to compile.
 
-    port install hs-cabal-install
 
-Let cabal update itself, in case your distro version is outdated:
+#### Installing Cabal
+
+ShellCheck is built and packaged using Cabal. Install the package `cabal-install` from your system's package manager (with e.g. `apt-get`, `yum`, `zypper` or `brew`).
+
+On MacPorts, the package is instead called `hs-cabal-install`, while native Windows users should install the latest version of the Haskell platform from https://www.haskell.org/platform/
+
+Verify that `cabal` is installed and update its dependency list with
 
     $ cabal update
-    $ cabal install cabal-install
 
-With cabal installed, cd to the ShellCheck source directory and:
+#### Compiling ShellCheck
+
+`git clone` this repository, and `cd` to the ShellCheck source directory to build/install:
 
     $ cabal install
 
-This will install ShellCheck to your ~/.cabal/bin directory.
+This will compile ShellCheck and install it to your `~/.cabal/bin` directory.
 
-Add the directory to your PATH (for bash, add this to your ~/.bashrc file):
+Add this directory to your `PATH` (for bash, add this to your `~/.bashrc`):
 
-    export PATH=$HOME/.cabal/bin:$PATH
+    export PATH="$HOME/.cabal/bin:$PATH"
 
-Verify that your PATH is set up correctly:
+Log out and in again, and verify that your PATH is set up correctly:
 
     $ which shellcheck
     ~/.cabal/bin/shellcheck
 
-## Running tests
+On native Windows, the `PATH` should already be set up, but the system
+may use a legacy codepage. In `cmd.exe`, `powershell.exe` and Powershell ISE,
+make sure to use a TrueType font, not a Raster font, and set the active
+codepage to UTF-8 (65001) with `chcp`:
+
+    > chcp 65001
+    Active code page: 65001
+
+In Powershell ISE, you may need to additionally update the output encoding:
+
+    > [Console]::OutputEncoding = [System.Text.Encoding]::UTF8
+
+#### Running tests
 
 To run the unit test suite:
 
-    cabal configure --enable-tests
-    cabal build
-    cabal test
+    $ cabal test
+
+
+## Gallery of bad code
+So what kind of things does ShellCheck look for? Here is an incomplete list of detected issues.
+
+#### Quoting
+
+ShellCheck can recognize several types of incorrect quoting:
+
+    echo $1                           # Unquoted variables
+    find . -name *.ogg                # Unquoted find/grep patterns
+    rm "~/my file.txt"                # Quoted tilde expansion
+    v='--verbose="true"'; cmd $v      # Literal quotes in variables
+    for f in "*.ogg"                  # Incorrectly quoted 'for' loops
+    touch $@                          # Unquoted $@
+    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
+
+
+#### Conditionals
+
+ShellCheck can recognize many types of incorrect test statements.
+
+    [[ n != 0 ]]                      # Constant test expressions
+    [[ -e *.mpg ]]                    # Existence checks of globs
+    [[ $foo==0 ]]                     # Always true due to missing spaces
+    [[ -n "$foo " ]]                  # Always true due to literals
+    [[ $foo =~ "fo+" ]]               # Quoted regex in =~
+    [ foo =~ re ]                     # Unsupported [ ] operators
+    [ $1 -eq "shellcheck" ]           # Numerical comparison of strings
+    [ $n && $m ]                      # && in [ .. ]
+    [ grep -q foo file ]              # Command without $(..)
+
+
+#### Frequently misused commands
+
+ShellCheck can recognize instances where commands are used incorrectly:
+
+    grep '*foo*' file                 # Globs in regex contexts
+    find . -exec foo {} && bar {} \;  # Prematurely terminated find -exec
+    sudo echo 'Var=42' > /etc/profile # Redirecting sudo
+    time --format=%s sleep 10         # Passing time(1) flags to time builtin
+    while read h; do ssh "$h" uptime  # Commands eating while loop input
+    alias archive='mv $1 /backup'     # Defining aliases with arguments
+    tr -cd '[a-zA-Z0-9]'              # [] around ranges in tr
+    exec foo; echo "Done!"            # Misused 'exec'
+    find -name \*.bak -o -name \*~ -delete  # Implicit precedence in find
+    f() { whoami; }; sudo f           # External use of internal functions
+
+
+#### Common beginner's mistakes
+
+ShellCheck recognizes many common beginner's syntax errors:
+
+    var = 42                          # Spaces around = in assignments
+    $foo=42                           # $ in assignments
+    for $var in *; do ...             # $ in for loop variables
+    var$n="Hello"                     # Wrong indirect assignment
+    echo ${var$n}                     # Wrong indirect reference
+    var=(1, 2, 3)                     # Comma separated arrays
+    echo "Argument 10 is $10"         # Positional parameter misreference
+    if $(myfunction); then ..; fi     # Wrapping commands in $()
+    else if othercondition; then ..   # Using 'else if'
+
+
+#### Style
+
+ShellCheck can make suggestions to improve style:
+
+    [[ -z $(find /tmp | grep mpg) ]]  # Use grep -q instead
+    a >> log; b >> log; c >> log      # Use a redirection block instead
+    echo "The time is `date`"         # Use $() instead
+    cd dir; process *; cd ..;         # Use subshells instead
+    echo $[1+2]                       # Use standard $((..)) instead of old $[]
+    echo $(($RANDOM % 6))             # Don't use $ on variables in $((..))
+    echo "$(date)"                    # Useless use of echo
+    cat file | grep foo               # Useless use of cat
+
+
+#### Data and typing errors
+
+ShellCheck can recognize issues related to data and typing:
+
+    args="$@"                         # Assigning arrays to strings
+    files=(foo bar); echo "$files"    # Referencing arrays as strings
+    printf "%s\n" "Arguments: $@."    # Concatenating strings and arrays.
+    [[ $# > 2 ]]                      # Comparing numbers as strings
+    var=World; echo "Hello " var      # Unused lowercase variables
+    echo "Hello $name"                # Unassigned lowercase variables
+    cmd | read bar; echo $bar         # Assignments in subshells
+
+
+#### Robustness
+
+ShellCheck can make suggestions for improving the robustness of a script:
+
+    rm -rf "$STEAMROOT/"*            # Catastrophic rm
+    touch ./-l; ls *                 # Globs that could become options
+    find . -exec sh -c 'a && b {}' \; # Find -exec shell injection
+    printf "Hello $name"             # Variables in printf format
+    for f in $(ls *.txt); do         # Iterating over ls output
+    export MYVAR=$(cmd)              # Masked exit codes
+
+
+#### Portability
+
+ShellCheck will warn when using features not supported by the shebang. For example, if you set the shebang to `#!/bin/sh`, ShellCheck will warn about portability issues similar to `checkbashisms`:
+
+
+    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
+    trap 'exit 42' sigint            # Unportable signal spec
+    cmd &> file                      # Unportable redirection operator
+    read foo < /dev/tcp/host/22      # Unportable intercepted files
+    foo-bar() { ..; }                # Undefined/unsupported function name
+    [ $UID = 0 ]                     # Variable undefined in dash/sh
+    local var=value                  # local is undefined in sh
+
+
+#### Miscellaneous
+
+ShellCheck recognizes a menagerie of other issues:
+
+    PS1='\e[0;32m\$\e[0m '            # PS1 colors not in \[..\]
+    PATH="$PATH:~/bin"                # Literal tilde in $PATH
+    rm “file”                         # Unicode quotes
+    echo "Hello world"                # Carriage return / DOS line endings
+    var=42 echo $var                  # Expansion of inlined environment
+    #!/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
+
+
+## Testimonials
+
+> At first you're like "shellcheck is awesome" but then you're like "wtf are we still using bash"
+
+Alexander Tarasikov,
+[via Twitter](https://twitter.com/astarasikov/status/568825996532707330)
+
+
+## Reporting bugs
+
+Please use the GitHub issue tracker for any bugs or feature suggestions:
+
+https://github.com/koalaman/shellcheck/issues
+
+
+## Contributing
+
+Please submit patches to code or documentation as GitHub pull requests!
+
+Contributions must be licensed under the GNU GPLv3.
+The contributor retains the copyright.
+
+
+## Copyright
+
+ShellCheck is licensed under the GNU General Public License, v3. A copy of this license is included in the file [LICENSE](LICENSE).
+
+Copyright 2012-2015, Vidar 'koala_man' Holen and contributors.
 
 Happy ShellChecking!

Setup.hs

@@ -1,2 +1,36 @@
-import Distribution.Simple
-main = defaultMain
+import Distribution.PackageDescription (
+  HookedBuildInfo,
+  emptyHookedBuildInfo )
+import Distribution.Simple (
+  Args,
+  UserHooks ( preSDist ),
+  defaultMainWithHooks,
+  simpleUserHooks )
+import Distribution.Simple.Setup ( SDistFlags )
+
+import System.Process ( system )
+
+
+main = defaultMainWithHooks myHooks
+  where
+    myHooks = simpleUserHooks { preSDist = myPreSDist }
+
+-- | This hook will be executed before e.g. @cabal sdist@. It runs
+--   pandoc to create the man page from shellcheck.1.md. If the pandoc
+--   command is not found, this will fail with an error message:
+--
+--     /bin/sh: pandoc: command not found
+--
+--   Since the man page is listed in the Extra-Source-Files section of
+--   our cabal file, a failure here should result in a failure to
+--   create the distribution tarball (that's a good thing).
+--
+myPreSDist :: Args -> SDistFlags -> IO HookedBuildInfo
+myPreSDist _ _ = do
+  putStrLn "Building the man page (shellcheck.1) with pandoc..."
+  putStrLn pandoc_cmd
+  result <- system pandoc_cmd
+  putStrLn $ "pandoc exited with " ++ show result
+  return emptyHookedBuildInfo
+  where
+    pandoc_cmd = "pandoc -s -t man shellcheck.1.md -o shellcheck.1"

ShellCheck.cabal

@@ -1,13 +1,13 @@
 Name:             ShellCheck
-Version:          0.3.5
+Version:          0.4.4
 Synopsis:         Shell script analysis tool
-License:          AGPL-3
+License:          GPL-3
 License-file:     LICENSE
 Category:         Static Analysis
 Author:           Vidar Holen
 Maintainer:       vidar@vidarholen.net
 Homepage:         http://www.shellcheck.net/
-Build-Type:       Simple
+Build-Type:       Custom
 Cabal-Version:    >= 1.8
 Bug-reports:      https://github.com/koalaman/shellcheck/issues
 Description:
@@ -26,6 +26,8 @@ Extra-Source-Files:
     -- documentation
     README.md
     shellcheck.1.md
+    -- built with a cabal sdist hook
+    shellcheck.1
     -- tests
     test/shellcheck.hs
 
@@ -39,17 +41,29 @@ library
       containers,
       directory,
       json,
-      mtl,
+      mtl >= 2.2.1,
       parsec,
-      regex-compat,
-      QuickCheck >= 2.7.4
+      regex-tdfa,
+      QuickCheck >= 2.7.4,
+      -- When cabal supports it, move this to setup-depends:
+      process
     exposed-modules:
-      ShellCheck.Analytics
       ShellCheck.AST
+      ShellCheck.ASTLib
+      ShellCheck.Analytics
+      ShellCheck.Analyzer
+      ShellCheck.AnalyzerLib
+      ShellCheck.Checker
+      ShellCheck.Checks.Commands
       ShellCheck.Data
-      ShellCheck.Options
+      ShellCheck.Formatter.Format
+      ShellCheck.Formatter.CheckStyle
+      ShellCheck.Formatter.GCC
+      ShellCheck.Formatter.JSON
+      ShellCheck.Formatter.TTY
+      ShellCheck.Interface
       ShellCheck.Parser
-      ShellCheck.Simple
+      ShellCheck.Regex
     other-modules:
       Paths_ShellCheck
 
@@ -60,10 +74,9 @@ executable shellcheck
       containers,
       directory,
       json,
-      mtl,
+      mtl >= 2.2.1,
       parsec,
-      regex-compat,
-      transformers,
+      regex-tdfa,
       QuickCheck >= 2.7.4
     main-is: shellcheck.hs
 
@@ -75,10 +88,9 @@ test-suite test-shellcheck
       containers,
       directory,
       json,
-      mtl,
+      mtl >= 2.2.1,
       parsec,
-      regex-compat,
-      transformers,
+      regex-tdfa,
       QuickCheck >= 2.7.4
     main-is: test/shellcheck.hs
 

ShellCheck/AST.hs

@@ -1,25 +1,27 @@
 {-
+    Copyright 2012-2015 Vidar Holen
+
     This file is part of ShellCheck.
     http://www.vidarholen.net/contents/shellcheck
 
     ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
+    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 Affero General Public License for more details.
+    GNU General Public License for more details.
 
-    You should have received a copy of the GNU Affero General Public License
+    You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 -}
 module ShellCheck.AST where
 
 import Control.Monad
 import Control.Monad.Identity
-import qualified Text.Regex as Re
+import qualified ShellCheck.Regex as Re
 
 data Id = Id Int deriving (Show, Eq, Ord)
 
@@ -28,11 +30,11 @@ data Dashed = Dashed | Undashed deriving (Show, Eq)
 data AssignmentMode = Assign | Append deriving (Show, Eq)
 data FunctionKeyword = FunctionKeyword Bool deriving (Show, Eq)
 data FunctionParentheses = FunctionParentheses Bool deriving (Show, Eq)
-data ForInType = NormalForIn | ShortForIn deriving (Show, Eq)
 data CaseType = CaseBreak | CaseFallThrough | CaseContinue deriving (Show, Eq)
 
 data Token =
     TA_Binary Id String Token Token
+    | TA_Assignment Id String Token Token
     | TA_Expansion Id [Token]
     | TA_Index Id Token
     | TA_Sequence Id [Token]
@@ -49,13 +51,12 @@ data Token =
     | T_Arithmetic Id Token
     | T_Array Id [Token]
     | T_IndexedElement Id Token Token
-    | T_ Id [Token]
     | T_Assignment Id AssignmentMode String (Maybe Token) Token
     | T_Backgrounded Id Token
     | T_Backticked Id [Token]
     | T_Bang Id
     | T_Banged Id Token
-    | T_BraceExpansion Id String
+    | T_BraceExpansion Id [Token]
     | T_BraceGroup Id [Token]
     | T_CLOBBER Id
     | T_Case Id
@@ -72,6 +73,7 @@ data Token =
     | T_DollarDoubleQuoted Id [Token]
     | T_DollarExpansion Id [Token]
     | T_DollarSingleQuoted Id String
+    | T_DollarBraceCommandExpansion Id [Token]
     | T_Done Id
     | T_DoubleQuoted Id [Token]
     | T_EOF Id
@@ -83,7 +85,7 @@ data Token =
     | T_Fi Id
     | T_For Id
     | T_ForArithmetic Id Token Token Token [Token]
-    | T_ForIn Id ForInType [String] [Token] [Token]
+    | T_ForIn Id String [Token] [Token]
     | T_Function Id FunctionKeyword FunctionParentheses String Token
     | T_GREATAND Id
     | T_Glob Id String
@@ -123,16 +125,25 @@ data Token =
     | T_WhileExpression Id [Token] [Token]
     | T_Annotation Id [Annotation] Token
     | T_Pipe Id String
+    | T_CoProc Id (Maybe String) Token
+    | T_CoProcBody Id Token
+    | T_Include Id Token Token -- . & source: SimpleCommand T_Script
     deriving (Show)
 
-data Annotation = DisableComment Integer deriving (Show, Eq)
+data Annotation =
+    DisableComment Integer
+    | SourceOverride String
+    | ShellOverride String
+    deriving (Show, Eq)
 data ConditionType = DoubleBracket | SingleBracket deriving (Show, Eq)
 
--- I apologize for nothing!
-lolHax s = Re.subRegex (Re.mkRegex "(Id [0-9]+)") (show s) "(Id 0)"
-instance Eq Token where
-    (==) a b = lolHax a == lolHax b
+-- This is an abomination.
+tokenEquals :: Token -> Token -> Bool
+tokenEquals a b = kludge a == kludge b
+    where kludge s = Re.subRegex (Re.mkRegex "\\(Id [0-9]+\\)") (show s) "(Id 0)"
 
+instance Eq Token where
+    (==) = tokenEquals
 
 analyze :: Monad m => (Token -> m ()) -> (Token -> m ()) -> (Token -> Token) -> Token -> m Token
 analyze f g i =
@@ -156,7 +167,7 @@ analyze f g i =
     dll l m v = do
         x <- roundAll l
         y <- roundAll m
-        return $ v x m
+        return $ v x y
     d1 t v = do
         x <- round t
         return $ v x
@@ -169,6 +180,8 @@ analyze f g i =
     delve (T_DoubleQuoted id list) = dl list $ T_DoubleQuoted id
     delve (T_DollarDoubleQuoted id list) = dl list $ T_DollarDoubleQuoted id
     delve (T_DollarExpansion id list) = dl list $ T_DollarExpansion id
+    delve (T_DollarBraceCommandExpansion id list) = dl list $ T_DollarBraceCommandExpansion id
+    delve (T_BraceExpansion id list) = dl list $ T_BraceExpansion id
     delve (T_Backticked id list) = dl list $ T_Backticked id
     delve (T_DollarArithmetic id c) = d1 c $ T_DollarArithmetic id
     delve (T_DollarBracket id c) = d1 c $ T_DollarBracket id
@@ -205,7 +218,7 @@ analyze f g i =
     delve (T_BraceGroup id l) = dl l $ T_BraceGroup id
     delve (T_WhileExpression id c l) = dll c l $ T_WhileExpression id
     delve (T_UntilExpression id c l) = dll c l $ T_UntilExpression id
-    delve (T_ForIn id t v w l) = dll w l $ T_ForIn id t v
+    delve (T_ForIn id v w l) = dll w l $ T_ForIn id v
     delve (T_SelectIn id v w l) = dll w l $ T_SelectIn id v
     delve (T_CaseExpression id word cases) = do
         newWord <- round word
@@ -238,6 +251,7 @@ analyze f g i =
     delve (TC_Noary id typ token) = d1 token $ TC_Noary id typ
 
     delve (TA_Binary id op t1 t2) = d2 t1 t2 $ TA_Binary id op
+    delve (TA_Assignment id op t1 t2) = d2 t1 t2 $ TA_Assignment id op
     delve (TA_Unary id op t1) = d1 t1 $ TA_Unary id op
     delve (TA_Sequence id l) = dl l $ TA_Sequence id
     delve (TA_Trinary id t1 t2 t3) = do
@@ -248,6 +262,9 @@ analyze f g i =
     delve (TA_Expansion id t) = dl t $ TA_Expansion id
     delve (TA_Index id t) = d1 t $ TA_Index id
     delve (T_Annotation id anns t) = d1 t $ T_Annotation id anns
+    delve (T_CoProc id var body) = d1 body $ T_CoProc id var
+    delve (T_CoProcBody id t) = d1 t $ T_CoProcBody id
+    delve (T_Include id includer script) = d2 includer script $ T_Include id
     delve t = return t
 
 getId t = case t of
@@ -293,6 +310,7 @@ getId t = case t of
         T_DollarBraced id _  -> id
         T_DollarArithmetic id _  -> id
         T_BraceExpansion id _  -> id
+        T_DollarBraceCommandExpansion id _  -> id
         T_IoFile id _ _  -> id
         T_HereDoc id _ _ _ _ -> id
         T_HereString id _  -> id
@@ -312,7 +330,7 @@ getId t = case t of
         T_BraceGroup id _  -> id
         T_WhileExpression id _ _  -> id
         T_UntilExpression id _ _  -> id
-        T_ForIn id _ _ _ _  -> id
+        T_ForIn id _ _ _  -> id
         T_SelectIn id _ _ _  -> id
         T_CaseExpression id _ _ -> id
         T_Function id _ _ _ _  -> id
@@ -328,6 +346,7 @@ getId t = case t of
         TC_Unary id _ _ _  -> id
         TC_Noary id _ _  -> id
         TA_Binary id _ _ _  -> id
+        TA_Assignment id _ _ _  -> id
         TA_Unary id _ _  -> id
         TA_Sequence id _  -> id
         TA_Trinary id _ _ _  -> id
@@ -341,6 +360,9 @@ getId t = case t of
         T_DollarBracket id _ -> id
         T_Annotation id _ _ -> id
         T_Pipe id _ -> id
+        T_CoProc id _ _ -> id
+        T_CoProcBody id _ -> id
+        T_Include id _ _ -> id
 
 blank :: Monad m => Token -> m ()
 blank = const $ return ()
@@ -348,10 +370,3 @@ doAnalysis f = analyze f blank id
 doStackAnalysis startToken endToken = analyze startToken endToken id
 doTransform i = runIdentity . analyze blank blank i
 
-isLoop t = case t of
-        T_WhileExpression {} -> True
-        T_UntilExpression {} -> True
-        T_ForIn {} -> True
-        T_ForArithmetic {} -> True
-        T_SelectIn {}  -> True
-        _ -> False

ShellCheck/ASTLib.hs

@@ -0,0 +1,253 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.ASTLib where
+
+import ShellCheck.AST
+
+import Control.Monad
+import Data.List
+import Data.Maybe
+
+-- Is this a type of loop?
+isLoop t = case t of
+        T_WhileExpression {} -> True
+        T_UntilExpression {} -> True
+        T_ForIn {} -> True
+        T_ForArithmetic {} -> True
+        T_SelectIn {}  -> True
+        _ -> False
+
+-- Will this split into multiple words when used as an argument?
+willSplit x =
+  case x of
+    T_DollarBraced {} -> True
+    T_DollarExpansion {} -> True
+    T_Backticked {} -> True
+    T_BraceExpansion {} -> True
+    T_Glob {} -> True
+    T_Extglob {} -> True
+    T_NormalWord _ l -> any willSplit l
+    _ -> False
+
+isGlob (T_Extglob {}) = True
+isGlob (T_Glob {}) = True
+isGlob (T_NormalWord _ l) = any isGlob l
+isGlob _ = False
+
+-- Is this shell word a constant?
+isConstant token =
+    case token of
+        T_NormalWord _ l   -> all isConstant l
+        T_DoubleQuoted _ l -> all isConstant l
+        T_SingleQuoted _ _ -> True
+        T_Literal _ _ -> True
+        _ -> False
+
+-- Is this an empty literal?
+isEmpty token =
+    case token of
+        T_NormalWord _ l   -> all isEmpty l
+        T_DoubleQuoted _ l -> all isEmpty l
+        T_SingleQuoted _ "" -> True
+        T_Literal _ "" -> True
+        _ -> False
+
+-- Quick&lazy oversimplification of commands, throwing away details
+-- and returning a list like  ["find", ".", "-name", "${VAR}*" ].
+oversimplify token =
+    case token of
+        (T_NormalWord _ l) -> [concat (concatMap oversimplify l)]
+        (T_DoubleQuoted _ l) -> [concat (concatMap oversimplify l)]
+        (T_SingleQuoted _ s) -> [s]
+        (T_DollarBraced _ _) -> ["${VAR}"]
+        (T_DollarArithmetic _ _) -> ["${VAR}"]
+        (T_DollarExpansion _ _) -> ["${VAR}"]
+        (T_Backticked _ _) -> ["${VAR}"]
+        (T_Glob _ s) -> [s]
+        (T_Pipeline _ _ [x]) -> oversimplify x
+        (T_Literal _ x) -> [x]
+        (T_SimpleCommand _ vars words) -> concatMap oversimplify words
+        (T_Redirecting _ _ foo) -> oversimplify foo
+        (T_DollarSingleQuoted _ s) -> [s]
+        (T_Annotation _ _ s) -> oversimplify s
+        -- Workaround for let "foo = bar" parsing
+        (TA_Sequence _ [TA_Expansion _ v]) -> concatMap oversimplify v
+        otherwise -> []
+
+
+-- Turn a SimpleCommand foo -avz --bar=baz into args "a", "v", "z", "bar",
+-- each in a tuple of (token, stringFlag). Non-flag arguments are added with
+-- stringFlag == "".
+getFlagsUntil stopCondition (T_SimpleCommand _ _ (_:args)) =
+    let tokenAndText = map (\x -> (x, concat $ oversimplify x)) args
+        (flagArgs, rest) = break (stopCondition . snd) tokenAndText
+    in
+        concatMap flag flagArgs ++ map (\(t, _) -> (t, "")) rest
+  where
+    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)"
+
+-- Get all flags in a GNU way, up until --
+getAllFlags = getFlagsUntil (== "--")
+-- Get all flags in a BSD way, up until first non-flag argument
+getLeadingFlags = getFlagsUntil (not . ("-" `isPrefixOf`))
+
+
+-- Given a T_DollarBraced, return a simplified version of the string contents.
+bracedString (T_DollarBraced _ l) = concat $ oversimplify l
+bracedString _ = error "Internal shellcheck error, please report! (bracedString on non-variable)"
+
+-- Is this an expansion of multiple items of an array?
+isArrayExpansion t@(T_DollarBraced _ _) =
+    let string = bracedString t in
+        "@" `isPrefixOf` string ||
+            not ("#" `isPrefixOf` string) && "[@]" `isInfixOf` string
+isArrayExpansion _ = False
+
+-- Is it possible that this arg becomes multiple args?
+mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f t
+  where
+    f t@(T_DollarBraced _ _) =
+        let string = bracedString t in
+            "!" `isPrefixOf` string
+    f (T_DoubleQuoted _ parts) = any f parts
+    f (T_NormalWord _ parts) = any f parts
+    f _ = False
+
+-- Is it certain that this word will becomes multiple words?
+willBecomeMultipleArgs t = willConcatInAssignment t || f t
+  where
+    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
+
+-- This does token cause implicit concatenation in assignments?
+willConcatInAssignment token =
+    case token of
+        t@(T_DollarBraced {}) -> isArrayExpansion t
+        (T_DoubleQuoted _ parts) -> any willConcatInAssignment parts
+        (T_NormalWord _ parts) -> any willConcatInAssignment parts
+        _ -> False
+
+-- Maybe get the literal string corresponding to this token
+getLiteralString :: Token -> Maybe String
+getLiteralString = getLiteralStringExt (const Nothing)
+
+-- Definitely get a literal string, skipping over all non-literals
+onlyLiteralString :: Token -> String
+onlyLiteralString = fromJust . getLiteralStringExt (const $ return "")
+
+-- Maybe get a literal string, but only if it's an unquoted argument.
+getUnquotedLiteral (T_NormalWord _ list) =
+    liftM concat $ mapM str list
+  where
+    str (T_Literal _ s) = return s
+    str _ = Nothing
+getUnquotedLiteral _ = Nothing
+
+-- Maybe get the literal string of this token and any globs in it.
+getGlobOrLiteralString = getLiteralStringExt f
+  where
+    f (T_Glob _ str) = return str
+    f _ = Nothing
+
+-- Maybe get the literal value of a token, using a custom function
+-- to map unrecognized Tokens into strings.
+getLiteralStringExt :: (Token -> Maybe String) -> Token -> Maybe String
+getLiteralStringExt more = g
+  where
+    allInList = liftM concat . mapM g
+    g (T_DoubleQuoted _ l) = allInList l
+    g (T_DollarDoubleQuoted _ l) = allInList l
+    g (T_NormalWord _ l) = allInList l
+    g (TA_Expansion _ l) = allInList l
+    g (T_SingleQuoted _ s) = return s
+    g (T_Literal _ s) = return s
+    g x = more x
+
+-- Is this token a string literal?
+isLiteral t = isJust $ getLiteralString t
+
+
+-- Turn a NormalWord like foo="bar $baz" into a series of constituent elements like [foo=,bar ,$baz]
+getWordParts (T_NormalWord _ l)   = concatMap getWordParts l
+getWordParts (T_DoubleQuoted _ l) = l
+getWordParts other                = [other]
+
+-- Return a list of NormalWords that would result from brace expansion
+braceExpand (T_NormalWord id list) = take 1000 $ do
+    items <- mapM part list
+    return $ T_NormalWord id items
+  where
+    part (T_BraceExpansion id items) = do
+        item <- items
+        braceExpand item
+    part x = return x
+
+-- Maybe get the command name of a token representing a command
+getCommandName t =
+    case t of
+        T_Redirecting _ _ w -> getCommandName w
+        T_SimpleCommand _ _ (w:_) -> getLiteralString w
+        T_Annotation _ _ t -> getCommandName t
+        otherwise -> Nothing
+
+-- Get the basename of a token representing a command
+getCommandBasename = liftM basename . getCommandName
+  where
+    basename = reverse . takeWhile (/= '/') . reverse
+
+isAssignment t =
+    case t of
+        T_Redirecting _ _ w -> isAssignment w
+        T_SimpleCommand _ (w:_) [] -> True
+        T_Assignment {} -> True
+        T_Annotation _ _ w -> isAssignment w
+        otherwise -> False
+
+isOnlyRedirection t =
+    case t of
+        T_Pipeline _ _ [x] -> isOnlyRedirection x
+        T_Annotation _ _ w -> isOnlyRedirection w
+        T_Redirecting _ (_:_) c -> isOnlyRedirection c
+        T_SimpleCommand _ [] [] -> True
+        otherwise -> False
+
+isFunction t = case t of T_Function {} -> True; _ -> False
+
+-- Get the list of commands from tokens that contain them, such as
+-- the body of while loops and if statements.
+getCommandSequences t =
+    case t of
+        T_Script _ _ cmds -> [cmds]
+        T_BraceGroup _ cmds -> [cmds]
+        T_Subshell _ cmds -> [cmds]
+        T_WhileExpression _ _ cmds -> [cmds]
+        T_UntilExpression _ _ cmds -> [cmds]
+        T_ForIn _ _ _ cmds -> [cmds]
+        T_ForArithmetic _ _ _ _ cmds -> [cmds]
+        T_IfExpression _ thens elses -> map snd thens ++ [elses]
+        otherwise -> []
+

ShellCheck/Analyzer.hs

@@ -0,0 +1,36 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Analyzer (analyzeScript) where
+
+import ShellCheck.Analytics
+import ShellCheck.AnalyzerLib
+import ShellCheck.Interface
+import Data.List
+import qualified ShellCheck.Checks.Commands
+
+
+-- TODO: Clean up the cruft this is layered on
+analyzeScript :: AnalysisSpec -> AnalysisResult
+analyzeScript spec = AnalysisResult {
+    arComments =
+        filterByAnnotation (asScript spec) . nub $
+            runAnalytics spec
+            ++ ShellCheck.Checks.Commands.runChecks spec
+}

ShellCheck/AnalyzerLib.hs

@@ -0,0 +1,632 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE FlexibleContexts #-}
+module ShellCheck.AnalyzerLib where
+import ShellCheck.AST
+import ShellCheck.ASTLib
+import ShellCheck.Data
+import ShellCheck.Interface
+import ShellCheck.Parser
+import ShellCheck.Regex
+
+import Control.Arrow (first)
+import Control.Monad.Identity
+import Control.Monad.Reader
+import Control.Monad.State
+import Control.Monad.Writer
+import Data.Char
+import Data.List
+import Data.Maybe
+import qualified Data.Map as Map
+
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
+
+type Analysis = ReaderT Parameters (Writer [TokenComment]) ()
+
+
+data Parameters = Parameters {
+    variableFlow :: [StackData],
+    parentMap :: Map.Map Id Token,
+    shellType :: Shell,
+    shellTypeSpecified :: Bool
+    }
+
+data Scope = SubshellScope String | NoneScope deriving (Show, Eq)
+data StackData =
+    StackScope Scope
+    | StackScopeEnd
+    -- (Base expression, specific position, var name, assigned values)
+    | Assignment (Token, Token, String, DataType)
+    | Reference (Token, Token, String)
+  deriving (Show)
+
+data DataType = DataString DataSource | DataArray DataSource
+  deriving (Show)
+
+data DataSource = SourceFrom [Token] | SourceExternal | SourceDeclaration | SourceInteger
+  deriving (Show)
+
+data VariableState = Dead Token String | Alive deriving (Show)
+
+defaultSpec root = AnalysisSpec {
+    asScript = root,
+    asShellType = Nothing,
+    asExecutionMode = Executed
+}
+
+pScript s =
+  let
+    pSpec = ParseSpec {
+        psFilename = "script",
+        psScript = s
+    }
+  in prRoot . runIdentity $ parseScript (mockedSystemInterface []) pSpec
+
+makeComment :: Severity -> Id -> Code -> String -> TokenComment
+makeComment severity id code note =
+    TokenComment id $ Comment severity code note
+
+addComment note = tell [note]
+
+warn :: MonadWriter [TokenComment] m => Id -> Code -> String -> m ()
+warn  id code str = addComment $ makeComment WarningC id code str
+err   id code str = addComment $ makeComment ErrorC id code str
+info  id code str = addComment $ makeComment InfoC id code str
+style id code str = addComment $ makeComment StyleC id code str
+
+makeParameters spec =
+    let params = Parameters {
+        shellType = fromMaybe (determineShell root) $ asShellType spec,
+        shellTypeSpecified = isJust $ asShellType spec,
+        parentMap = getParentTree root,
+        variableFlow =
+            getVariableFlow (shellType params) (parentMap params) root
+    } in params
+  where root = asScript spec
+
+prop_determineShell0 = determineShell (fromJust $ pScript "#!/bin/sh") == Sh
+prop_determineShell1 = determineShell (fromJust $ pScript "#!/usr/bin/env ksh") == Ksh
+prop_determineShell2 = determineShell (fromJust $ pScript "") == Bash
+prop_determineShell3 = determineShell (fromJust $ pScript "#!/bin/sh -e") == Sh
+prop_determineShell4 = determineShell (fromJust $ pScript
+    "#!/bin/ksh\n#shellcheck shell=sh\nfoo") == Sh
+prop_determineShell5 = determineShell (fromJust $ pScript
+    "#shellcheck shell=sh\nfoo") == Sh
+prop_determineShell6 = determineShell (fromJust $ pScript "#! /bin/sh") == Sh
+determineShell t = fromMaybe Bash $ do
+    shellString <- foldl mplus Nothing $ getCandidates t
+    shellForExecutable shellString
+  where
+    forAnnotation t =
+        case t of
+            (ShellOverride s) -> return s
+            _ -> fail ""
+    getCandidates :: Token -> [Maybe String]
+    getCandidates t@(T_Script {}) = [Just $ fromShebang t]
+    getCandidates (T_Annotation _ annotations s) =
+        map forAnnotation annotations ++
+           [Just $ fromShebang s]
+    fromShebang (T_Script _ s t) = shellFor s
+
+    shellFor s | "/env " `isInfixOf` s = head (drop 1 (words s)++[""])
+    shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
+    shellFor s = reverse . takeWhile (/= '/') . reverse $ s
+
+
+--- Context seeking
+
+getParentTree t =
+    snd . snd $ runState (doStackAnalysis pre post t) ([], Map.empty)
+  where
+    pre t = modify (first ((:) t))
+    post t = do
+        (_:rest, map) <- get
+        case rest of [] -> put (rest, map)
+                     (x:_) -> put (rest, Map.insert (getId t) x map)
+
+getTokenMap t =
+    execState (doAnalysis f t) Map.empty
+  where
+    f t = modify (Map.insert (getId t) t)
+
+
+-- Is this node self quoting for a regular element?
+isQuoteFree = isQuoteFreeNode False
+
+-- Is this node striclty self quoting, for array expansions
+isStrictlyQuoteFree = isQuoteFreeNode True
+
+
+isQuoteFreeNode strict tree t =
+    (isQuoteFreeElement t == Just True) ||
+        head (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t) ++ [False])
+  where
+    -- Is this node self-quoting in itself?
+    isQuoteFreeElement t =
+        case t of
+            T_Assignment {} -> return True
+            T_FdRedirect {} -> return True
+            _ -> Nothing
+
+    -- Are any subnodes inherently self-quoting?
+    isQuoteFreeContext t =
+        case t of
+            TC_Noary _ DoubleBracket _ -> return True
+            TC_Unary _ DoubleBracket _ _ -> return True
+            TC_Binary _ DoubleBracket _ _ _ -> return True
+            TA_Sequence {} -> return True
+            T_Arithmetic {} -> return True
+            T_Assignment {} -> return True
+            T_Redirecting {} -> return $
+                if strict then False else
+                    -- Not true, just a hack to prevent warning about non-expansion refs
+                    any (isCommand t) ["local", "declare", "typeset", "export", "trap", "readonly"]
+            T_DoubleQuoted _ _ -> return True
+            T_DollarDoubleQuoted _ _ -> return True
+            T_CaseExpression {} -> return True
+            T_HereDoc {} -> return True
+            T_DollarBraced {} -> return True
+            -- When non-strict, pragmatically assume it's desirable to split here
+            T_ForIn {} -> return (not strict)
+            T_SelectIn {} -> return (not strict)
+            _ -> Nothing
+
+isParamTo tree cmd =
+    go
+  where
+    go x = case Map.lookup (getId x) tree of
+                Nothing -> False
+                Just parent -> check parent
+    check t =
+        case t of
+            T_SingleQuoted _ _ -> go t
+            T_DoubleQuoted _ _ -> go t
+            T_NormalWord _ _ -> go t
+            T_SimpleCommand {} -> isCommand t cmd
+            T_Redirecting {} -> isCommand t cmd
+            _ -> False
+
+getClosestCommand tree t =
+    msum . map getCommand $ getPath tree t
+  where
+    getCommand t@(T_Redirecting {}) = return t
+    getCommand _ = Nothing
+
+usedAsCommandName tree token = go (getId token) (tail $ getPath tree token)
+  where
+    go currentId (T_NormalWord id [word]:rest)
+        | currentId == getId word = go id rest
+    go currentId (T_DoubleQuoted id [word]:rest)
+        | currentId == getId word = go id rest
+    go currentId (T_SimpleCommand _ _ (word:_):_)
+        | currentId == getId word = True
+    go _ _ = False
+
+-- A list of the element and all its parents
+getPath tree t = t :
+    case Map.lookup (getId t) tree of
+        Nothing -> []
+        Just parent -> getPath tree parent
+
+isParentOf tree parent child =
+    elem (getId parent) . map getId $ getPath tree child
+
+parents params = getPath (parentMap params)
+
+pathTo t = do
+    parents <- reader parentMap
+    return $ getPath parents t
+
+-- Check whether a word is entirely output from a single command
+tokenIsJustCommandOutput t = case t of
+    T_NormalWord id [T_DollarExpansion _ cmds] -> check cmds
+    T_NormalWord id [T_DoubleQuoted _ [T_DollarExpansion _ cmds]] -> check cmds
+    T_NormalWord id [T_Backticked _ cmds] -> check cmds
+    T_NormalWord id [T_DoubleQuoted _ [T_Backticked _ cmds]] -> check cmds
+    _ -> False
+  where
+    check [x] = not $ isOnlyRedirection x
+    check _ = False
+
+-- TODO: Replace this with a proper Control Flow Graph
+getVariableFlow shell parents t =
+    let (_, stack) = runState (doStackAnalysis startScope endScope t) []
+    in reverse stack
+  where
+    startScope t =
+        let scopeType = leadType shell parents t
+        in do
+            when (scopeType /= NoneScope) $ modify (StackScope scopeType:)
+            when (assignFirst t) $ setWritten t
+
+    endScope t =
+        let scopeType = leadType shell parents t
+        in do
+            setRead t
+            unless (assignFirst t) $ setWritten t
+            when (scopeType /= NoneScope) $ modify (StackScopeEnd:)
+
+    assignFirst (T_ForIn {}) = True
+    assignFirst (T_SelectIn {}) = True
+    assignFirst _ = False
+
+    setRead t =
+        let read    = getReferencedVariables parents t
+        in mapM_ (\v -> modify (Reference v:)) read
+
+    setWritten t =
+        let written = getModifiedVariables t
+        in mapM_ (\v -> modify (Assignment v:)) written
+
+
+leadType shell parents t =
+    case t of
+        T_DollarExpansion _ _  -> SubshellScope "$(..) expansion"
+        T_Backticked _ _  -> SubshellScope "`..` expansion"
+        T_Backgrounded _ _  -> SubshellScope "backgrounding &"
+        T_Subshell _ _  -> SubshellScope "(..) group"
+        T_CoProcBody _ _  -> SubshellScope "coproc"
+        T_Redirecting {}  ->
+            if fromMaybe False causesSubshell
+            then SubshellScope "pipeline"
+            else NoneScope
+        _ -> NoneScope
+  where
+    parentPipeline = do
+        parent <- Map.lookup (getId t) parents
+        case parent of
+            T_Pipeline {} -> return parent
+            _ -> Nothing
+
+    causesSubshell = do
+        (T_Pipeline _ _ list) <- parentPipeline
+        if length list <= 1
+            then return False
+            else if lastCreatesSubshell
+                then return True
+                else return . not $ (getId . head $ reverse list) == getId t
+
+    lastCreatesSubshell =
+        case shell of
+            Bash -> True
+            Dash -> True
+            Sh -> True
+            Ksh -> False
+
+getModifiedVariables t =
+    case t of
+        T_SimpleCommand _ vars [] ->
+            concatMap (\x -> case x of
+                                T_Assignment id _ name _ w  ->
+                                    [(x, x, name, dataTypeFrom DataString w)]
+                                _ -> []
+                      ) vars
+        c@(T_SimpleCommand {}) ->
+            getModifiedVariableCommand c
+
+        TA_Unary _ "++|" var -> maybeToList $ do
+            name <- getLiteralString var
+            return (t, t, name, DataString $ SourceFrom [t])
+        TA_Unary _ "|++" var -> maybeToList $ do
+            name <- getLiteralString var
+            return (t, t, name, DataString $ SourceFrom [t])
+        TA_Assignment _ op lhs rhs -> maybeToList $ do
+            guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
+            name <- getLiteralString lhs
+            return (t, t, name, DataString $ SourceFrom [rhs])
+
+        t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&2 modifies foo
+            [(t, t, takeWhile (/= '}') var, DataString SourceInteger) | not $ isClosingFileOp op]
+
+        t@(T_CoProc _ name _) ->
+            [(t, t, fromMaybe "COPROC" name, DataArray SourceInteger)]
+
+        --Points to 'for' rather than variable
+        T_ForIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
+        T_SelectIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
+        _ -> []
+
+isClosingFileOp op =
+    case op of
+        T_IoFile _ (T_GREATAND _) (T_NormalWord _ [T_Literal _ "-"]) -> True
+        T_IoFile _ (T_LESSAND  _) (T_NormalWord _ [T_Literal _ "-"]) -> 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
+        "export" -> if "f" `elem` flags
+            then []
+            else concatMap getReference rest
+        "declare" -> if any (`elem` flags) ["x", "p"]
+            then concatMap getReference rest
+            else []
+        "readonly" -> concatMap getReference rest
+        "trap" ->
+            case rest of
+                head:_ -> map (\x -> (head, head, x)) $ getVariablesFromLiteralToken head
+                _ -> []
+        _ -> []
+  where
+    getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)]
+    getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)]
+    getReference _ = []
+    flags = map snd $ getAllFlags base
+
+getReferencedVariableCommand _ = []
+
+getModifiedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
+   filter (\(_,_,s,_) -> not ("-" `isPrefixOf` s)) $
+    case x of
+        "read" ->
+            let params = map getLiteral rest in
+                catMaybes . takeWhile isJust . reverse $ params
+        "getopts" ->
+            case rest of
+                opts:var:_ -> maybeToList $ getLiteral var
+                _ -> []
+
+        "let" -> concatMap letParamToLiteral rest
+
+        "export" ->
+            if "f" `elem` flags then [] else concatMap getModifierParamString rest
+
+        "declare" -> if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
+        "typeset" -> declaredVars
+
+        "local" -> concatMap getModifierParamString rest
+        "readonly" -> concatMap getModifierParamString rest
+        "set" -> maybeToList $ do
+            params <- getSetParams rest
+            return (base, base, "@", DataString $ SourceFrom params)
+
+        "printf" -> maybeToList $ getPrintfVariable rest
+
+        "mapfile" -> maybeToList $ getMapfileArray base rest
+        "readarray" -> maybeToList $ getMapfileArray base rest
+
+        _ -> []
+  where
+    flags = map snd $ getAllFlags base
+    stripEquals s = let rest = dropWhile (/= '=') s in
+        if rest == "" then "" else tail rest
+    stripEqualsFrom (T_NormalWord id1 (T_Literal id2 s:rs)) =
+        T_NormalWord id1 (T_Literal id2 (stripEquals s):rs)
+    stripEqualsFrom (T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 s]]) =
+        T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 (stripEquals s)]]
+    stripEqualsFrom t = t
+
+    declaredVars = concatMap (getModifierParam defaultType) rest
+      where
+        defaultType = if any (`elem` flags) ["a", "A"] then DataArray else DataString
+
+    getLiteral t = do
+        s <- getLiteralString t
+        when ("-" `isPrefixOf` s) $ fail "argument"
+        return (base, t, s, DataString SourceExternal)
+
+    getModifierParamString = getModifierParam DataString
+
+    getModifierParam def t@(T_Assignment _ _ name _ value) =
+        [(base, t, name, dataTypeFrom def value)]
+    getModifierParam def t@(T_NormalWord {}) = maybeToList $ do
+        name <- getLiteralString t
+        guard $ isVariableName name
+        return (base, t, name, def SourceDeclaration)
+    getModifierParam _ _ = []
+
+    letParamToLiteral token =
+          if var == ""
+            then []
+            else [(base, token, var, DataString $ SourceFrom [stripEqualsFrom token])]
+        where var = takeWhile isVariableChar $ dropWhile (`elem` "+-") $ concat $ oversimplify token
+
+    getSetParams (t:_:rest) | getLiteralString t == Just "-o" = getSetParams rest
+    getSetParams (t:rest) =
+        let s = getLiteralString t in
+            case s of
+                Just "--" -> return rest
+                Just ('-':_) -> getSetParams rest
+                _ -> return (t:fromMaybe [] (getSetParams rest))
+    getSetParams [] = Nothing
+
+    getPrintfVariable list = f $ map (\x -> (x, getLiteralString x)) list
+      where
+        f ((_, Just "-v") : (t, Just var) : _) = return (base, t, var, DataString $ SourceFrom list)
+        f (_:rest) = f rest
+        f [] = fail "not found"
+
+    -- mapfile has some curious syntax allowing flags plus 0..n variable names
+    -- where only the first non-option one is used if any. Here we cheat and
+    -- just get the last one, if it's a variable name.
+    getMapfileArray base arguments = do
+        lastArg <- listToMaybe (reverse arguments)
+        name <- getLiteralString lastArg
+        guard $ isVariableName name
+        return (base, lastArg, name, DataArray SourceExternal)
+
+getModifiedVariableCommand _ = []
+
+getIndexReferences s = fromMaybe [] $ do
+    match <- matchRegex re s
+    index <- match !!! 0
+    return $ matchAllStrings variableNameRegex index
+  where
+    re = mkRegex "(\\[.*\\])"
+
+getReferencedVariables parents t =
+    case t of
+        T_DollarBraced id l -> let str = bracedString t in
+            (t, t, getBracedReference str) :
+                map (\x -> (l, l, x)) (getIndexReferences str)
+        TA_Expansion id _ ->
+            if isArithmeticAssignment t
+            then []
+            else getIfReference t t
+        T_Assignment id mode str _ word ->
+            [(t, t, str) | mode == Append] ++ specialReferences str t word
+
+        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
+            then concatMap (getIfReference t) [lhs, rhs]
+            else []
+
+        t@(T_FdRedirect _ ('{':var) op) -> -- {foo}>&- references and closes foo
+            [(t, t, takeWhile (/= '}') var) | isClosingFileOp op]
+        x -> getReferencedVariableCommand x
+  where
+    -- Try to reduce false positives for unused vars only referenced from evaluated vars
+    specialReferences name base word =
+        if name `elem` [
+            "PS1", "PS2", "PS3", "PS4",
+            "PROMPT_COMMAND"
+          ]
+        then
+            map (\x -> (base, base, x)) $
+                getVariablesFromLiteralToken word
+        else []
+
+    literalizer (TA_Index {}) = return ""  -- x[0] becomes a reference of x
+    literalizer _ = Nothing
+
+    getIfReference context token = maybeToList $ do
+            str <- getLiteralStringExt literalizer token
+            guard . not $ null str
+            when (isDigit $ head str) $ 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 _ "=" _ _ :_ -> True
+        _ -> False
+
+dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
+
+
+--- Command specific checks
+
+isCommand token str = isCommandMatch token (\cmd -> cmd  == str || ('/' : str) `isSuffixOf` cmd)
+isUnqualifiedCommand token str = isCommandMatch token (== str)
+
+isCommandMatch token matcher = fromMaybe False $ do
+    cmd <- getCommandName token
+    return $ matcher cmd
+
+isConfusedGlobRegex ('*':_) = True
+isConfusedGlobRegex [x,'*'] | x /= '\\' = 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 (fromJust $ getLiteralStringExt (const $ return " ") token)
+
+-- Try to get referenced variables from a literal string like "$foo"
+-- Ignores tons of cases like arithmetic evaluation and array indices.
+prop_getVariablesFromLiteral1 =
+    getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
+getVariablesFromLiteral string =
+    map (!! 0) $ matchAllSubgroups variableRegex string
+  where
+    variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
+
+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_getBracedReference12= getBracedReference "!os?bar**" == ""
+getBracedReference s = fromMaybe s $
+    nameExpansion s `mplus` takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
+  where
+    noPrefix = dropPrefix s
+    dropPrefix (c:rest) = if c `elem` "!#" then rest else c:rest
+    dropPrefix "" = ""
+    takeName s = do
+        let name = takeWhile isVariableChar s
+        guard . not $ null name
+        return name
+    getSpecial (c:_) =
+        if c `elem` "*@#?-$!" then return [c] else fail "not special"
+    getSpecial _ = fail "empty"
+
+    nameExpansion ('!':rest) = do -- e.g. ${!foo*bar*}
+        let suffix = dropWhile isVariableChar rest
+        guard $ suffix /= rest -- e.g. ${!@}
+        first <- suffix !!! 0
+        guard $ first `elem` "*?"
+        return ""
+    nameExpansion _ = Nothing
+
+
+-- Useful generic functions
+potentially :: Monad m => Maybe (m ()) -> m ()
+potentially = fromMaybe (return ())
+
+headOrDefault _ (a:_) = a
+headOrDefault def _ = def
+
+(!!!) list i =
+    case drop i list of
+        [] -> Nothing
+        (r:_) -> Just r
+
+
+
+filterByAnnotation token =
+    filter (not . shouldIgnore)
+  where
+    idFor (TokenComment id _) = id
+    shouldIgnore note =
+        any (shouldIgnoreFor (getCode note)) $
+            getPath parents (T_Bang $ idFor note)
+    shouldIgnoreFor num (T_Annotation _ anns _) =
+        any hasNum anns
+      where
+        hasNum (DisableComment ts) = num == ts
+        hasNum _ = False
+    shouldIgnoreFor _ (T_Include {}) = True -- Ignore included files
+    shouldIgnoreFor _ _ = False
+    parents = getParentTree token
+    getCode (TokenComment _ (Comment _ c _)) = c
+
+
+return [] 
+runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

ShellCheck/Checker.hs

@@ -0,0 +1,162 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.Checker (checkScript, ShellCheck.Checker.runTests) where
+
+import ShellCheck.Interface
+import ShellCheck.Parser
+import ShellCheck.Analyzer
+
+import Data.Either
+import Data.Functor
+import Data.List
+import Data.Maybe
+import Data.Ord
+import Control.Monad.Identity
+import qualified Data.Map as Map
+import qualified System.IO
+import Prelude hiding (readFile)
+import Control.Monad
+
+import Test.QuickCheck.All
+
+tokenToPosition map (TokenComment id c) = fromMaybe fail $ do
+    position <- Map.lookup id map
+    return $ PositionedComment position c
+  where
+    fail = error "Internal shellcheck error: id doesn't exist. Please report!"
+
+checkScript :: Monad m => SystemInterface m -> CheckSpec -> m CheckResult
+checkScript sys spec = do
+    results <- checkScript (csScript spec)
+    return CheckResult {
+        crFilename = csFilename spec,
+        crComments = results
+    }
+  where
+    checkScript contents = do
+        result <- parseScript sys ParseSpec {
+            psFilename = csFilename spec,
+            psScript = contents
+        }
+        let parseMessages = prComments result
+        let analysisMessages =
+                fromMaybe [] $
+                    (arComments . analyzeScript . analysisSpec)
+                        <$> prRoot result
+        let translator = tokenToPosition (prTokenPositions result)
+        return . nub . sortMessages . filter shouldInclude $
+            (parseMessages ++ map translator analysisMessages)
+
+    shouldInclude (PositionedComment _ (Comment _ code _)) =
+        code `notElem` csExcludedWarnings spec
+
+    sortMessages = sortBy (comparing order)
+    order (PositionedComment pos (Comment severity code message)) =
+        (posFile pos, posLine pos, posColumn pos, severity, code, message)
+    getPosition (PositionedComment pos _) = pos
+
+    analysisSpec root =
+        AnalysisSpec {
+            asScript = root,
+            asShellType = csShellTypeOverride spec,
+            asExecutionMode = Executed
+         }
+
+getErrors sys spec =
+    sort . map getCode . crComments $
+        runIdentity (checkScript sys spec)
+  where
+    getCode (PositionedComment _ (Comment _ code _)) = code
+
+check = checkWithIncludes []
+
+checkWithIncludes includes src =
+    getErrors
+        (mockedSystemInterface includes)
+        emptyCheckSpec {
+            csScript = src,
+            csExcludedWarnings = [2148]
+        }
+
+prop_findsParseIssue = check "echo \"$12\"" == [1037]
+
+prop_commentDisablesParseIssue1 =
+    null $ check "#shellcheck disable=SC1037\necho \"$12\""
+prop_commentDisablesParseIssue2 =
+    null $ check "#shellcheck disable=SC1037\n#lol\necho \"$12\""
+
+prop_findsAnalysisIssue =
+    check "echo $1" == [2086]
+prop_commentDisablesAnalysisIssue1 =
+    null $ check "#shellcheck disable=SC2086\necho $1"
+prop_commentDisablesAnalysisIssue2 =
+    null $ check "#shellcheck disable=SC2086\n#lol\necho $1"
+
+prop_optionDisablesIssue1 =
+    null $ getErrors
+                (mockedSystemInterface [])
+                emptyCheckSpec {
+                    csScript = "echo $1",
+                    csExcludedWarnings = [2148, 2086]
+                }
+
+prop_optionDisablesIssue2 =
+    null $ getErrors
+                (mockedSystemInterface [])
+                emptyCheckSpec {
+                    csScript = "echo \"$10\"",
+                    csExcludedWarnings = [2148, 1037]
+                }
+
+prop_canParseDevNull =
+    [] == check "source /dev/null"
+
+prop_failsWhenNotSourcing =
+    [1091, 2154] == check "source lol; echo \"$bar\""
+
+prop_worksWhenSourcing =
+    null $ checkWithIncludes [("lib", "bar=1")] "source lib; echo \"$bar\""
+
+prop_worksWhenDotting =
+    null $ checkWithIncludes [("lib", "bar=1")] ". lib; echo \"$bar\""
+
+prop_noInfiniteSourcing =
+    [] == checkWithIncludes  [("lib", "source lib")] "source lib"
+
+prop_canSourceBadSyntax =
+    [1094, 2086] == checkWithIncludes [("lib", "for f; do")] "source lib; echo $1"
+
+prop_cantSourceDynamic =
+    [1090] == checkWithIncludes [("lib", "")] ". \"$1\""
+
+prop_cantSourceDynamic2 =
+    [1090] == checkWithIncludes [("lib", "")] "source ~/foo"
+
+prop_canSourceDynamicWhenRedirected =
+    null $ checkWithIncludes [("lib", "")] "#shellcheck source=lib\n. \"$1\""
+
+prop_sourceDirectiveDoesntFollowFile =
+    null $ checkWithIncludes
+                [("foo", "source bar"), ("bar", "baz=3")]
+                "#shellcheck source=foo\n. \"$1\"; echo \"$baz\""
+
+return []
+runTests = $quickCheckAll

ShellCheck/Checks/Commands.hs

@@ -0,0 +1,560 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE FlexibleContexts #-}
+
+-- This module contains checks that examine specific commands by name.
+module ShellCheck.Checks.Commands (runChecks
+    , ShellCheck.Checks.Commands.runTests
+) where
+
+import ShellCheck.AST
+import ShellCheck.ASTLib
+import ShellCheck.AnalyzerLib
+import ShellCheck.Data
+import ShellCheck.Interface
+import ShellCheck.Parser
+import ShellCheck.Regex
+
+import Control.Monad
+import Control.Monad.Reader
+import Control.Monad.Writer
+import Data.Char
+import Data.List
+import Data.Maybe
+import qualified Data.Map as Map
+import Test.QuickCheck.All (forAllProperties)
+import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
+
+data CommandName = Exactly String | Basename String
+    deriving (Eq, Ord)
+
+data CommandCheck =
+    CommandCheck CommandName (Token -> Analysis)
+
+nullCheck :: Token -> Analysis
+nullCheck _ = return ()
+
+
+verify :: CommandCheck -> String -> Bool
+verify f s = producesComments f s == Just True
+verifyNot f s = producesComments f s == Just False
+
+producesComments :: CommandCheck -> String -> Maybe Bool
+producesComments f s = do
+        root <- pScript s
+        return . not . null $ runList (defaultSpec root) [f]
+
+composeChecks f g t = do
+    f t
+    g t
+
+arguments (T_SimpleCommand _ _ (cmd:args)) = args
+
+commandChecks :: [CommandCheck]
+commandChecks = [
+    checkTr
+    ,checkFindNameGlob
+    ,checkNeedlessExpr
+    ,checkGrepRe
+    ,checkTrapQuotes
+    ,checkReturn
+    ,checkFindExecWithSingleArgument
+    ,checkUnusedEchoEscapes
+    ,checkInjectableFindSh
+    ,checkFindActionPrecedence
+    ,checkMkdirDashPM
+    ,checkNonportableSignals
+    ,checkInteractiveSu
+    ,checkSshCommandString
+    ,checkPrintfVar
+    ,checkUuoeCmd
+    ,checkSetAssignment
+    ,checkExportedExpansions
+    ,checkAliasesUsesArgs
+    ,checkAliasesExpandEarly
+    ]
+
+buildCommandMap :: [CommandCheck] -> Map.Map CommandName (Token -> Analysis)
+buildCommandMap = foldl' addCheck Map.empty
+  where
+    addCheck map (CommandCheck name function) =
+        Map.insertWith' composeChecks name function map
+
+
+checkCommand :: Map.Map CommandName (Token -> Analysis) -> Token -> Analysis
+checkCommand map t@(T_SimpleCommand id _ (cmd:rest)) = fromMaybe (return ()) $ do
+    name <- getLiteralString cmd
+    return $
+        if '/' `elem` name
+        then
+            Map.findWithDefault nullCheck (Basename $ basename name) map t
+        else do
+            Map.findWithDefault nullCheck (Exactly name) map t
+            Map.findWithDefault nullCheck (Basename name) map t
+
+  where
+    basename = reverse . takeWhile (/= '/') . reverse
+checkCommand _ _ = return ()
+
+runList spec list = notes
+    where
+        root = asScript spec
+        params = makeParameters spec
+        notes = execWriter $ runReaderT (doAnalysis (checkCommand map) root) params
+        map = buildCommandMap list
+
+runChecks spec = runList spec commandChecks
+
+
+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_checkTr3 = verifyNot checkTr "tr -d '[:lower:]'"
+prop_checkTr3a= 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_checkTr11= verifyNot checkTr "tr abc '[d*]'"
+checkTr = CommandCheck (Basename "tr") (mapM_ f . arguments)
+  where
+    f w | isGlob w = -- The user will go [ab] -> '[ab]' -> 'ab'. Fixme?
+        warn (getId w) 2060 "Quote parameters to tr to prevent glob expansion."
+    f word =
+      case getLiteralString word of
+        Just "a-z" -> info (getId word) 2018 "Use '[:lower:]' to support accents and foreign alphabets."
+        Just "A-Z" -> info (getId word) 2019 "Use '[:upper:]' to support accents and foreign alphabets."
+        Just s -> do  -- Eliminate false positives by only looking for dupes in SET2?
+          when (not ("-" `isPrefixOf` s || "[:" `isInfixOf` s) && duplicated s) $
+            info (getId word) 2020 "tr replaces sets of chars, not words (mentioned due to duplicates)."
+          unless ("[:" `isPrefixOf` s) $
+            when ("[" `isPrefixOf` s && "]" `isSuffixOf` s && (length s > 2) && ('*' `notElem` s)) $
+              info (getId word) 2021 "Don't use [] around ranges in tr, it replaces literal square brackets."
+        Nothing -> return ()
+
+    duplicated s =
+        let relevant = filter isAlpha s
+        in relevant /= nub relevant
+
+prop_checkFindNameGlob1 = verify checkFindNameGlob "find / -name *.php"
+prop_checkFindNameGlob2 = verify checkFindNameGlob "find / -type f -ipath *(foo)"
+prop_checkFindNameGlob3 = verifyNot checkFindNameGlob "find * -name '*.php'"
+checkFindNameGlob = CommandCheck (Basename "find") (f . arguments)  where
+    acceptsGlob (Just s) = s `elem` [ "-ilname", "-iname", "-ipath", "-iregex", "-iwholename", "-lname", "-name", "-path", "-regex", "-wholename" ]
+    acceptsGlob _ = False
+    f [] = return ()
+    f [x] = return ()
+    f (a:b:r) = do
+        when (acceptsGlob (getLiteralString a) && isGlob b) $ do
+            let (Just s) = getLiteralString a
+            warn (getId b) 2061 $ "Quote the parameter to " ++ s ++ " so the shell won't interpret it."
+        f (b:r)
+
+
+prop_checkNeedlessExpr = verify checkNeedlessExpr "foo=$(expr 3 + 2)"
+prop_checkNeedlessExpr2 = verify checkNeedlessExpr "foo=`echo \\`expr 3 + 2\\``"
+prop_checkNeedlessExpr3 = verifyNot checkNeedlessExpr "foo=$(expr foo : regex)"
+prop_checkNeedlessExpr4 = verifyNot checkNeedlessExpr "foo=$(expr foo \\< regex)"
+checkNeedlessExpr = CommandCheck (Basename "expr") f where
+    f t =
+        when (all (`notElem` exceptions) (words $ arguments t)) $
+            style (getId t) 2003
+                "expr is antiquated. Consider rewriting this using $((..)), ${} or [[ ]]."
+    -- These operators are hard to replicate in POSIX
+    exceptions = [ ":", "<", ">", "<=", ">=" ]
+    words = mapMaybe getLiteralString
+
+
+prop_checkGrepRe1 = verify checkGrepRe "cat foo | grep *.mp3"
+prop_checkGrepRe2 = verify checkGrepRe "grep -Ev cow*test *.mp3"
+prop_checkGrepRe3 = verify checkGrepRe "grep --regex=*.mp3 file"
+prop_checkGrepRe4 = verifyNot checkGrepRe "grep foo *.mp3"
+prop_checkGrepRe5 = verifyNot checkGrepRe "grep-v  --regex=moo *"
+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_checkGrepRe11= verifyNot checkGrepRe "grep --include=*.png foo"
+
+checkGrepRe = CommandCheck (Basename "grep") (f . arguments) where
+    -- --regex=*(extglob) doesn't work. Fixme?
+    skippable (Just s) = not ("--regex=" `isPrefixOf` s) && "-" `isPrefixOf` s
+    skippable _ = False
+    f [] = return ()
+    f (x:r) | skippable (getLiteralStringExt (const $ return "_") x) = f r
+    f (re:_) = do
+        when (isGlob re) $
+            warn (getId re) 2062 "Quote the grep pattern so the shell won't interpret it."
+        let string = concat $ oversimplify re
+        if isConfusedGlobRegex string then
+            warn (getId re) 2063 "Grep uses regex, but this looks like a glob."
+          else potentially $ do
+            char <- getSuspiciousRegexWildcard string
+            return $ info (getId re) 2022 $
+                "Note that unlike globs, " ++ [char] ++ "* here matches '" ++ [char, char, char] ++ "' but not '" ++ wordStartingWith char ++ "'."
+
+    wordStartingWith c =
+        head . filter ([c] `isPrefixOf`) $ candidates
+      where
+        candidates =
+            sampleWords ++ map (\(x:r) -> toUpper x : r) sampleWords ++ [c:"test"]
+
+    getSuspiciousRegexWildcard str =
+        if not $ str `matches` contra
+        then do
+            match <- matchRegex suspicious str
+            str <- match !!! 0
+            str !!! 0
+        else
+            fail "looks good"
+      where
+        suspicious = mkRegex "([A-Za-z1-9])\\*"
+        contra = mkRegex "[^a-zA-Z1-9]\\*|[][^$+\\\\]"
+
+
+prop_checkTrapQuotes1 = verify checkTrapQuotes "trap \"echo $num\" 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
+    f (x:_) = checkTrap x
+    f _ = return ()
+    checkTrap (T_NormalWord _ [T_DoubleQuoted _ rs]) = mapM_ checkExpansions rs
+    checkTrap _ = return ()
+    warning id = warn id 2064 "Use single quotes, otherwise this expands now rather than when signalled."
+    checkExpansions (T_DollarExpansion id _) = warning id
+    checkExpansions (T_Backticked id _) = warning id
+    checkExpansions (T_DollarBraced id _) = warning id
+    checkExpansions (T_DollarArithmetic id _) = warning id
+    checkExpansions _ = return ()
+
+
+prop_checkReturn1 = verifyNot checkReturn "return"
+prop_checkReturn2 = verifyNot checkReturn "return 1"
+prop_checkReturn3 = verifyNot checkReturn "return $var"
+prop_checkReturn4 = verifyNot checkReturn "return $((a|b))"
+prop_checkReturn5 = verify checkReturn "return -1"
+prop_checkReturn6 = verify checkReturn "return 1000"
+prop_checkReturn7 = verify checkReturn "return 'hello world'"
+checkReturn = CommandCheck (Exactly "return") (f . arguments)
+  where
+    f (first:second:_) =
+        err (getId second) 2151
+            "Only one integer 0-255 can be returned. Use stdout for other data."
+    f [value] =
+        when (isInvalid $ literal value) $
+            err (getId value) 2152
+                "Can only return 0-255. Other data should be written to stdout."
+    f _ = return ()
+
+    isInvalid s = s == "" || any (not . isDigit) s || length s > 5
+        || let value = (read s :: Integer) in value > 255
+
+    literal token = fromJust $ getLiteralStringExt lit token
+    lit (T_DollarBraced {}) = return "0"
+    lit (T_DollarArithmetic {}) = return "0"
+    lit (T_DollarExpansion {}) = return "0"
+    lit (T_Backticked {}) = return "0"
+    lit _ = return "WTF"
+
+
+prop_checkFindExecWithSingleArgument1 = verify checkFindExecWithSingleArgument "find . -exec 'cat {} | wc -l' \\;"
+prop_checkFindExecWithSingleArgument2 = verify checkFindExecWithSingleArgument "find . -execdir 'cat {} | wc -l' +"
+prop_checkFindExecWithSingleArgument3 = verifyNot checkFindExecWithSingleArgument "find . -exec wc -l {} \\;"
+checkFindExecWithSingleArgument = CommandCheck (Basename "find") (f . arguments)
+  where
+    f = void . sequence . mapMaybe check . tails
+    check (exec:arg:term:_) = do
+        execS <- getLiteralString exec
+        termS <- getLiteralString term
+        cmdS <- getLiteralStringExt (const $ return " ") arg
+
+        guard $ execS `elem` ["-exec", "-execdir"] && termS `elem` [";", "+"]
+        guard $ cmdS `matches` commandRegex
+        return $ warn (getId exec) 2150 "-exec does not invoke a shell. Rewrite or use -exec sh -c .. ."
+    check _ = Nothing
+    commandRegex = mkRegex "[ |;]"
+
+
+prop_checkUnusedEchoEscapes1 = verify checkUnusedEchoEscapes "echo 'foo\\nbar\\n'"
+prop_checkUnusedEchoEscapes2 = verifyNot checkUnusedEchoEscapes "echo -e 'foi\\nbar'"
+prop_checkUnusedEchoEscapes3 = verify checkUnusedEchoEscapes "echo \"n:\\t42\""
+prop_checkUnusedEchoEscapes4 = verifyNot checkUnusedEchoEscapes "echo lol"
+prop_checkUnusedEchoEscapes5 = verifyNot checkUnusedEchoEscapes "echo -n -e '\n'"
+checkUnusedEchoEscapes = CommandCheck (Basename "echo") (f . arguments)
+  where
+    isDashE = mkRegex "^-.*e"
+    hasEscapes = mkRegex "\\\\[rnt]"
+    f args | concat (concatMap oversimplify allButLast) `matches` isDashE =
+        return ()
+      where allButLast = reverse . drop 1 . reverse $ args
+    f args = mapM_ checkEscapes args
+
+    checkEscapes (T_NormalWord _ args) =
+        mapM_ checkEscapes args
+    checkEscapes (T_DoubleQuoted id args) =
+        mapM_ checkEscapes args
+    checkEscapes (T_Literal id str) = examine id str
+    checkEscapes (T_SingleQuoted id str) = examine id str
+    checkEscapes _ = return ()
+
+    examine id str =
+        when (str `matches` hasEscapes) $
+            info id 2028 "echo won't expand escape sequences. Consider printf."
+
+
+prop_checkInjectableFindSh1 = verify checkInjectableFindSh "find . -exec sh -c 'echo {}' \\;"
+prop_checkInjectableFindSh2 = verify checkInjectableFindSh "find . -execdir bash -c 'rm \"{}\"' ';'"
+prop_checkInjectableFindSh3 = verifyNot checkInjectableFindSh "find . -exec sh -c 'rm \"$@\"' _ {} \\;"
+checkInjectableFindSh = CommandCheck (Basename "find") (check . arguments)
+  where
+    check args = do
+        let idStrings = map (\x -> (getId x, onlyLiteralString x)) args
+        match pattern idStrings
+
+    match _ [] = return ()
+    match [] (next:_) = action next
+    match (p:tests) ((id, arg):args) = do
+        when (p arg) $ match tests args
+        match (p:tests) args
+
+    pattern = [
+        (`elem` ["-exec", "-execdir"]),
+        (`elem` ["sh", "bash", "ksh"]),
+        (== "-c")
+        ]
+    action (id, arg) =
+        when ("{}" `isInfixOf` arg) $
+            warn id 2156 "Injecting filenames is fragile and insecure. Use parameters."
+
+
+prop_checkFindActionPrecedence1 = verify checkFindActionPrecedence "find . -name '*.wav' -o -name '*.au' -exec rm {} +"
+prop_checkFindActionPrecedence2 = verifyNot checkFindActionPrecedence "find . -name '*.wav' -o \\( -name '*.au' -exec rm {} + \\)"
+prop_checkFindActionPrecedence3 = verifyNot checkFindActionPrecedence "find . -name '*.wav' -o -name '*.au'"
+checkFindActionPrecedence = CommandCheck (Basename "find") (f . arguments)
+  where
+    pattern = [isMatch, const True, isParam ["-o", "-or"], isMatch, const True, isAction]
+    f list | length list < length pattern = return ()
+    f list@(_:rest) =
+        if and (zipWith ($) pattern list)
+        then warnFor (list !! (length pattern - 1))
+        else f rest
+    isMatch = isParam [ "-name", "-regex", "-iname", "-iregex", "-wholename", "-iwholename" ]
+    isAction = isParam [ "-exec", "-execdir", "-delete", "-print", "-print0" ]
+    isParam strs t = fromMaybe False $ do
+        param <- getLiteralString t
+        return $ param `elem` strs
+    warnFor t = warn (getId t) 2146 "This action ignores everything before the -o. Use \\( \\) to group."
+
+
+prop_checkMkdirDashPM0 = verify checkMkdirDashPM "mkdir -p -m 0755 a/b"
+prop_checkMkdirDashPM1 = verify checkMkdirDashPM "mkdir -pm 0755 $dir"
+prop_checkMkdirDashPM2 = verify checkMkdirDashPM "mkdir -vpm 0755 a/b"
+prop_checkMkdirDashPM3 = verify checkMkdirDashPM "mkdir -pm 0755 -v a/b"
+prop_checkMkdirDashPM4 = verify checkMkdirDashPM "mkdir --parents --mode=0755 a/b"
+prop_checkMkdirDashPM5 = verify checkMkdirDashPM "mkdir --parents --mode 0755 a/b"
+prop_checkMkdirDashPM6 = verify checkMkdirDashPM "mkdir -p --mode=0755 a/b"
+prop_checkMkdirDashPM7 = verify checkMkdirDashPM "mkdir --parents -m 0755 a/b"
+prop_checkMkdirDashPM8 = verifyNot checkMkdirDashPM "mkdir -p a/b"
+prop_checkMkdirDashPM9 = verifyNot checkMkdirDashPM "mkdir -m 0755 a/b"
+prop_checkMkdirDashPM10 = verifyNot checkMkdirDashPM "mkdir a/b"
+prop_checkMkdirDashPM11 = verifyNot checkMkdirDashPM "mkdir --parents a/b"
+prop_checkMkdirDashPM12 = verifyNot checkMkdirDashPM "mkdir --mode=0755 a/b"
+prop_checkMkdirDashPM13 = verifyNot checkMkdirDashPM "mkdir_func -pm 0755 a/b"
+prop_checkMkdirDashPM14 = verifyNot checkMkdirDashPM "mkdir -p -m 0755 singlelevel"
+checkMkdirDashPM = CommandCheck (Basename "mkdir") check
+  where
+    check t = potentially $ do
+        let flags = getAllFlags t
+        dashP <- find ((\f -> f == "p" || f == "parents") . snd) flags
+        dashM <- find ((\f -> f == "m" || f == "mode") . snd) flags
+        guard $ any couldHaveSubdirs (drop 1 $ arguments t) -- mkdir -pm 0700 dir  is fine, but dir/subdir is not.
+        return $ warn (getId $ fst dashM) 2174 "When used with -p, -m only applies to the deepest directory."
+    couldHaveSubdirs t = fromMaybe True $ do
+        name <- getLiteralString t
+        return $ '/' `elem` name
+
+
+prop_checkNonportableSignals1 = verify checkNonportableSignals "trap f 8"
+prop_checkNonportableSignals2 = verifyNot checkNonportableSignals "trap f 0"
+prop_checkNonportableSignals3 = verifyNot checkNonportableSignals "trap f 14"
+prop_checkNonportableSignals4 = verify checkNonportableSignals "trap f SIGKILL"
+prop_checkNonportableSignals5 = verify checkNonportableSignals "trap f 9"
+prop_checkNonportableSignals6 = verify checkNonportableSignals "trap f stop"
+checkNonportableSignals = CommandCheck (Exactly "trap") (f . arguments)
+  where
+    f = mapM_ check
+    check param = potentially $ do
+        str <- getLiteralString param
+        let id = getId param
+        return $ sequence_ $ mapMaybe (\f -> f id str) [
+            checkNumeric,
+            checkUntrappable
+            ]
+
+    checkNumeric id str = do
+        guard $ not (null str)
+        guard $ all isDigit str
+        guard $ str /= "0" -- POSIX exit trap
+        guard $ str `notElem` ["1", "2", "3", "6", "9", "14", "15" ] -- XSI
+        return $ warn id 2172
+            "Trapping signals by number is not well defined. Prefer signal names."
+
+    checkUntrappable id str = do
+        guard $ map toLower str `elem` ["kill", "9", "sigkill", "stop", "sigstop"]
+        return $ err id 2173
+            "SIGKILL/SIGSTOP can not be trapped."
+
+
+prop_checkInteractiveSu1 = verify checkInteractiveSu "su; rm file; su $USER"
+prop_checkInteractiveSu2 = verify checkInteractiveSu "su foo; something; exit"
+prop_checkInteractiveSu3 = verifyNot checkInteractiveSu "echo rm | su foo"
+prop_checkInteractiveSu4 = verifyNot checkInteractiveSu "su root < script"
+checkInteractiveSu = CommandCheck (Basename "su") f
+  where
+    f cmd = when (length (arguments cmd) <= 1) $ do
+        path <- pathTo cmd
+        when (all undirected path) $
+            info (getId cmd) 2117
+                "To run commands as another user, use su -c or sudo."
+
+    undirected (T_Pipeline _ _ l) = length l <= 1
+    -- This should really just be modifications to stdin, but meh
+    undirected (T_Redirecting _ list _) = null list
+    undirected _ = True
+
+
+-- This is hard to get right without properly parsing ssh args
+prop_checkSshCmdStr1 = verify checkSshCommandString "ssh host \"echo $PS1\""
+prop_checkSshCmdStr2 = verifyNot checkSshCommandString "ssh host \"ls foo\""
+prop_checkSshCmdStr3 = verifyNot checkSshCommandString "ssh \"$host\""
+checkSshCommandString = CommandCheck (Basename "ssh") (f . arguments)
+  where
+    nonOptions =
+        filter (\x -> not $ "-" `isPrefixOf` concat (oversimplify x))
+    f args =
+        case nonOptions args of
+            (hostport:r@(_:_)) -> checkArg $ last r
+            _ -> return ()
+    checkArg (T_NormalWord _ [T_DoubleQuoted id parts]) =
+        case filter (not . isConstant) parts of
+            [] -> return ()
+            (x:_) -> info (getId x) 2029
+                "Note that, unescaped, this expands on the client side."
+    checkArg _ = return ()
+
+
+prop_checkPrintfVar1 = verify checkPrintfVar "printf \"Lol: $s\""
+prop_checkPrintfVar2 = verifyNot checkPrintfVar "printf 'Lol: $s'"
+prop_checkPrintfVar3 = verify checkPrintfVar "printf -v cow $(cmd)"
+prop_checkPrintfVar4 = verifyNot checkPrintfVar "printf \"%${count}s\" var"
+checkPrintfVar = CommandCheck (Exactly "printf") (f . arguments) where
+    f (dashv:var:rest) | getLiteralString dashv == Just "-v" = f rest
+    f (format:params) = check format
+    f _ = return ()
+    check format =
+        unless ('%' `elem` concat (oversimplify format) || isLiteral format) $
+          warn (getId format) 2059
+              "Don't use variables in the printf format string. Use printf \"..%s..\" \"$foo\"."
+
+
+prop_checkUuoeCmd1 = verify checkUuoeCmd "echo $(date)"
+prop_checkUuoeCmd2 = verify checkUuoeCmd "echo `date`"
+prop_checkUuoeCmd3 = verify checkUuoeCmd "echo \"$(date)\""
+prop_checkUuoeCmd4 = verify checkUuoeCmd "echo \"`date`\""
+prop_checkUuoeCmd5 = verifyNot checkUuoeCmd "echo \"The time is $(date)\""
+prop_checkUuoeCmd6 = verifyNot checkUuoeCmd "echo \"$(<file)\""
+checkUuoeCmd = CommandCheck (Exactly "echo") (f . arguments) where
+    msg id = style id 2005 "Useless echo? Instead of 'echo $(cmd)', just use 'cmd'."
+    f [token] = when (tokenIsJustCommandOutput token) $ msg (getId token)
+    f _ = return ()
+
+
+prop_checkSetAssignment1 = verify checkSetAssignment "set foo 42"
+prop_checkSetAssignment2 = verify checkSetAssignment "set foo = 42"
+prop_checkSetAssignment3 = verify checkSetAssignment "set foo=42"
+prop_checkSetAssignment4 = verifyNot checkSetAssignment "set -- if=/dev/null"
+prop_checkSetAssignment5 = verifyNot checkSetAssignment "set 'a=5'"
+prop_checkSetAssignment6 = verifyNot checkSetAssignment "set"
+checkSetAssignment = CommandCheck (Exactly "set") (f . arguments)
+  where
+    f (var:value:rest) =
+        let str = literal var in
+            when (isVariableName str || isAssignment str) $
+                msg (getId var)
+    f (var:_) =
+        when (isAssignment $ literal var) $
+            msg (getId var)
+    f _ = return ()
+
+    msg id = warn id 2121 "To assign a variable, use just 'var=value', no 'set ..'."
+
+    isAssignment str = '=' `elem` str
+    literal (T_NormalWord _ l) = concatMap literal l
+    literal (T_Literal _ str) = str
+    literal _ = "*"
+
+
+prop_checkExportedExpansions1 = verify checkExportedExpansions "export $foo"
+prop_checkExportedExpansions2 = verify checkExportedExpansions "export \"$foo\""
+prop_checkExportedExpansions3 = verifyNot checkExportedExpansions "export foo"
+checkExportedExpansions = CommandCheck (Exactly "export") (check . arguments)
+  where
+    check = mapM_ checkForVariables
+    checkForVariables f =
+        case getWordParts f of
+            [t@(T_DollarBraced {})] ->
+                warn (getId t) 2163 "Exporting an expansion rather than a variable."
+            _ -> return ()
+
+
+prop_checkAliasesUsesArgs1 = verify checkAliasesUsesArgs "alias a='cp $1 /a'"
+prop_checkAliasesUsesArgs2 = verifyNot checkAliasesUsesArgs "alias $1='foo'"
+prop_checkAliasesUsesArgs3 = verify checkAliasesUsesArgs "alias a=\"echo \\${@}\""
+checkAliasesUsesArgs = CommandCheck (Exactly "alias") (f . arguments)
+  where
+    re = mkRegex "\\$\\{?[0-9*@]"
+    f = mapM_ checkArg
+    checkArg arg =
+        let string = fromJust $ getLiteralStringExt (const $ return "_") arg in
+            when ('=' `elem` string && string `matches` re) $
+                err (getId arg) 2142
+                    "Aliases can't use positional parameters. Use a function."
+
+
+prop_checkAliasesExpandEarly1 = verify checkAliasesExpandEarly "alias foo=\"echo $PWD\""
+prop_checkAliasesExpandEarly2 = verifyNot checkAliasesExpandEarly "alias -p"
+prop_checkAliasesExpandEarly3 = verifyNot checkAliasesExpandEarly "alias foo='echo {1..10}'"
+checkAliasesExpandEarly = CommandCheck (Exactly "alias") (f . arguments)
+  where
+    f = mapM_ checkArg
+    checkArg arg | '=' `elem` concat (oversimplify arg) =
+        forM_ (take 1 $ filter (not . isLiteral) $ getWordParts arg) $
+            \x -> warn (getId x) 2139 "This expands when defined, not when used. Consider escaping."
+    checkArg _ = return ()
+
+
+return []
+runTests =  $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])

ShellCheck/Data.hs

@@ -1,5 +1,6 @@
 module ShellCheck.Data where
 
+import ShellCheck.Interface
 import Data.Version (showVersion)
 import Paths_ShellCheck (version)
 
@@ -24,25 +25,14 @@ internalVariables = [
     "FUNCNEST", "GLOBIGNORE", "HISTCONTROL", "HISTFILE", "HISTFILESIZE",
     "HISTIGNORE", "HISTSIZE", "HISTTIMEFORMAT", "HOME", "HOSTFILE", "IFS",
     "IGNOREEOF", "INPUTRC", "LANG", "LC_ALL", "LC_COLLATE", "LC_CTYPE",
-    "LC_MESSAGES", "LC_NUMERIC", "LINES", "MAIL", "MAILCHECK", "MAILPATH",
-    "OPTERR", "PATH", "POSIXLY_CORRECT", "PROMPT_COMMAND",
-    "PROMPT_DIRTRIM", "PS1", "PS2", "PS3", "PS4", "SHELL", "TIMEFORMAT",
-    "TMOUT", "TMPDIR", "auto_resume", "histchars",
+    "LC_MESSAGES", "LC_MONETARY", "LC_NUMERIC", "LC_TIME", "LINES", "MAIL",
+    "MAILCHECK", "MAILPATH", "OPTERR", "PATH", "POSIXLY_CORRECT",
+    "PROMPT_COMMAND", "PROMPT_DIRTRIM", "PS1", "PS2", "PS3", "PS4", "SHELL",
+    "TIMEFORMAT", "TMOUT", "TMPDIR", "auto_resume", "histchars", "COPROC",
 
-    -- Zsh
-    "ARGV0", "BAUD", "cdpath", "COLUMNS", "CORRECT_IGNORE",
-    "DIRSTACKSIZE", "ENV", "FCEDIT", "fignore", "fpath", "histchars",
-    "HISTCHARS", "HISTFILE", "HISTSIZE", "HOME", "IFS", "KEYBOARD_HACK",
-    "KEYTIMEOUT", "LANG", "LC_ALL", "LC_COLLATE", "LC_CTYPE",
-    "LC_MESSAGES", "LC_NUMERIC", "LC_TIME", "LINES", "LISTMAX",
-    "LOGCHECK", "MAIL", "MAILCHECK", "mailpath", "manpath", "module_path",
-    "NULLCMD", "path", "POSTEDIT", "PROMPT", "PROMPT2", "PROMPT3",
-    "PROMPT4", "prompt", "PROMPT_EOL_MARK", "PS1", "PS2", "PS3", "PS4",
-    "psvar", "READNULLCMD", "REPORTTIME", "REPLY", "reply", "RPROMPT",
-    "RPS1", "RPROMPT2", "RPS2", "SAVEHIST", "SPROMPT", "STTY", "TERM",
-    "TERMINFO", "TIMEFMT", "TMOUT", "TMPPREFIX", "watch", "WATCHFMT",
-    "WORDCHARS", "ZBEEP", "ZDOTDIR", "ZLE_LINE_ABORTED",
-    "ZLE_REMOVE_SUFFIX_CHARS", "ZLE_SPACE_SUFFIX_CHARS"
+    -- Other
+    "USER", "TZ", "TERM", "LOGNAME", "LD_LIBRARY_PATH", "LANGUAGE", "DISPLAY",
+    "HOSTNAME", "KRB5CCNAME", "XAUTHORITY"
   ]
 
 variablesWithoutSpaces = [
@@ -52,6 +42,12 @@ variablesWithoutSpaces = [
     "COLUMNS", "HISTFILESIZE", "HISTSIZE", "LINES"
   ]
 
+arrayVariables = [
+    "BASH_ALIASES", "BASH_ARGC", "BASH_ARGV", "BASH_CMDS", "BASH_LINENO",
+    "BASH_REMATCH", "BASH_SOURCE", "BASH_VERSINFO", "COMP_WORDS", "COPROC",
+    "DIRSTACK", "FUNCNAME", "GROUPS", "MAPFILE", "PIPESTATUS", "COMPREPLY"
+  ]
+
 commonCommands = [
     "admin", "alias", "ar", "asa", "at", "awk", "basename", "batch",
     "bc", "bg", "break", "c99", "cal", "cat", "cd", "cflow", "chgrp",
@@ -85,3 +81,14 @@ sampleWords = [
     "tango", "uniform", "victor", "whiskey", "xray", "yankee",
     "zulu"
   ]
+
+shellForExecutable :: String -> Maybe Shell
+shellForExecutable name =
+    case name of
+        "sh"    -> return Sh
+        "bash"  -> return Bash
+        "dash"  -> return Dash
+        "ksh"   -> return Ksh
+        "ksh88" -> return Ksh
+        "ksh93" -> return Ksh
+        otherwise -> Nothing

ShellCheck/Formatter/CheckStyle.hs

@@ -0,0 +1,82 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.CheckStyle (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Data.Char
+import Data.List
+import GHC.Exts
+import System.IO
+
+format :: IO Formatter
+format = return Formatter {
+    header = do
+        putStrLn "<?xml version='1.0' encoding='UTF-8'?>"
+        putStrLn "<checkstyle version='4.3'>",
+
+    onFailure = outputError,
+    onResult = outputResult,
+
+    footer = putStrLn "</checkstyle>"
+}
+
+outputResult result contents = do
+    let comments = makeNonVirtual (crComments result) contents
+    putStrLn . formatFile (crFilename result) $ comments
+
+formatFile name comments = concat [
+    "<file ", attr "name" name, ">\n",
+        concatMap formatComment comments,
+    "</file>"
+    ]
+
+formatComment c = concat [
+    "<error ",
+    attr "line" $ show . lineNo $ c,
+    attr "column" $ show . colNo $ c,
+    attr "severity" . severity $ severityText c,
+    attr "message" $ messageText c,
+    attr "source" $ "ShellCheck.SC" ++ show (codeNo c),
+    "/>\n"
+    ]
+
+outputError file error = putStrLn $ concat [
+    "<file ", attr "name" file, ">\n",
+    "<error ",
+        attr "line" "1",
+        attr "column" "1",
+        attr "severity" "error",
+        attr "message" error,
+        attr "source" "ShellCheck",
+    "/>\n",
+    "</file>"
+    ]
+
+
+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` " ./")]
+
+severity "error" = "error"
+severity "warning" = "warning"
+severity _ = "info"

ShellCheck/Formatter/Format.hs

@@ -0,0 +1,61 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.Format where
+
+import ShellCheck.Data
+import ShellCheck.Interface
+
+-- A formatter that carries along an arbitrary piece of data
+data Formatter = Formatter {
+    header ::  IO (),
+    onResult :: CheckResult -> String -> IO (),
+    onFailure :: FilePath -> ErrorMessage -> IO (),
+    footer :: IO ()
+}
+
+lineNo (PositionedComment pos _) = posLine pos
+colNo  (PositionedComment pos _) = posColumn pos
+codeNo (PositionedComment _ (Comment _ code _)) = code
+messageText (PositionedComment _ (Comment _ _ t)) = t
+
+severityText :: PositionedComment -> String
+severityText (PositionedComment _ (Comment c _ _)) =
+    case c of
+        ErrorC   -> "error"
+        WarningC -> "warning"
+        InfoC    -> "info"
+        StyleC   -> "style"
+
+-- Realign comments from a tabstop of 8 to 1
+makeNonVirtual comments contents =
+    map fix comments
+  where
+    ls = lines contents
+    fix c@(PositionedComment pos comment) = PositionedComment pos {
+        posColumn =
+            if lineNo c > 0 && lineNo c <= fromIntegral (length ls)
+            then real (ls !! fromIntegral (lineNo c - 1)) 0 0 (colNo c)
+            else colNo c
+    } comment
+    real _ r v target | target <= v = r
+    real [] r v _ = r -- should never happen
+    real ('\t':rest) r v target =
+        real rest (r+1) (v + 8 - (v `mod` 8)) target
+    real (_:rest) r v target = real rest (r+1) (v+1) target

ShellCheck/Formatter/GCC.hs

@@ -0,0 +1,54 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.GCC (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Data.List
+import GHC.Exts
+import System.IO
+
+format :: IO Formatter
+format = return Formatter {
+    header = return (),
+    footer = return (),
+    onFailure = outputError,
+    onResult = outputResult
+}
+
+outputError file error = hPutStrLn stderr $ file ++ ": " ++ error
+
+outputResult result contents = do
+    let comments = makeNonVirtual (crComments result) contents
+    mapM_ (putStrLn . formatComment (crFilename result)) comments
+
+formatComment filename c = concat [
+    filename, ":",
+    show $ lineNo c, ":",
+    show $ colNo c, ": ",
+    case severityText c of
+        "error" -> "error"
+        "warning" -> "warning"
+        _ -> "note",
+    ": ",
+    concat . lines $ messageText c,
+    " [SC", show $ codeNo c, "]"
+  ]

ShellCheck/Formatter/JSON.hs

@@ -0,0 +1,58 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.JSON (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Data.IORef
+import GHC.Exts
+import System.IO
+import Text.JSON
+
+format = do
+    ref <- newIORef []
+    return Formatter {
+        header = return (),
+        onResult = collectResult ref,
+        onFailure = outputError,
+        footer = finish ref
+    }
+
+instance JSON (PositionedComment) where
+  showJSON comment@(PositionedComment pos (Comment level code string)) = makeObj [
+      ("file", showJSON $ posFile pos),
+      ("line", showJSON $ posLine pos),
+      ("column", showJSON $ posColumn pos),
+      ("level", showJSON $ severityText comment),
+      ("code", showJSON code),
+      ("message", showJSON string)
+      ]
+
+  readJSON = undefined
+
+outputError file msg = hPutStrLn stderr $ file ++ ": " ++ msg
+collectResult ref result _ =
+    modifyIORef ref (\x -> crComments result ++ x)
+
+finish ref = do
+    list <- readIORef ref
+    putStrLn $ encodeStrict list
+

ShellCheck/Formatter/TTY.hs

@@ -0,0 +1,91 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Formatter.TTY (format) where
+
+import ShellCheck.Interface
+import ShellCheck.Formatter.Format
+
+import Data.List
+import GHC.Exts
+import System.Info
+import System.IO
+
+format :: FormatterOptions -> IO Formatter
+format options = return Formatter {
+    header = return (),
+    footer = return (),
+    onFailure = outputError options,
+    onResult = outputResult options
+}
+
+colorForLevel level =
+    case level of
+        "error"   -> 31 -- red
+        "warning" -> 33 -- yellow
+        "info"    -> 32 -- green
+        "style"   -> 32 -- green
+        "message" -> 1 -- bold
+        "source"  -> 0 -- none
+        otherwise -> 0 -- none
+
+outputError options file error = do
+    color <- getColorFunc $ foColorOption options
+    hPutStrLn stderr $ color "error" $ file ++ ": " ++ error
+
+outputResult options result contents = do
+    color <- getColorFunc $ foColorOption options
+    let comments = crComments result
+    let fileLines = lines contents
+    let lineCount = fromIntegral $ length fileLines
+    let groups = groupWith lineNo comments
+    mapM_ (\x -> do
+        let lineNum = lineNo (head x)
+        let line = if lineNum < 1 || lineNum > lineCount
+                        then ""
+                        else fileLines !! fromIntegral (lineNum - 1)
+        putStrLn ""
+        putStrLn $ color "message" $
+           "In " ++ crFilename result ++" line " ++ show lineNum ++ ":"
+        putStrLn (color "source" line)
+        mapM_ (\c -> putStrLn (color (severityText c) $ cuteIndent c)) x
+        putStrLn ""
+      ) groups
+
+cuteIndent :: PositionedComment -> String
+cuteIndent comment =
+    replicate (fromIntegral $ colNo comment - 1) ' ' ++
+        "^-- " ++ code (codeNo comment) ++ ": " ++ messageText comment
+
+code code = "SC" ++ show code
+
+getColorFunc colorOption = do
+    term <- hIsTerminalDevice stdout
+    let windows = "mingw" `isPrefixOf` os
+    let isUsableTty = term && not windows
+    let useColor = case colorOption of
+                       ColorAlways -> True
+                       ColorNever -> False
+                       ColorAuto -> isUsableTty
+    return $ if useColor then colorComment else const id
+  where
+    colorComment level comment =
+        ansi (colorForLevel level) ++ comment ++ clear
+    clear = ansi 0
+    ansi n = "\x1B[" ++ show n ++ "m"

ShellCheck/Interface.hs

@@ -0,0 +1,116 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+module ShellCheck.Interface where
+
+import ShellCheck.AST
+import Control.Monad.Identity
+import qualified Data.Map as Map
+
+
+data SystemInterface m = SystemInterface {
+    -- Read a file by filename, or return an error
+    siReadFile :: String -> m (Either ErrorMessage String)
+}
+
+-- ShellCheck input and output
+data CheckSpec = CheckSpec {
+    csFilename :: String,
+    csScript :: String,
+    csExcludedWarnings :: [Integer],
+    csShellTypeOverride :: Maybe Shell
+} deriving (Show, Eq)
+
+data CheckResult = CheckResult {
+    crFilename :: String,
+    crComments :: [PositionedComment]
+} deriving (Show, Eq)
+
+emptyCheckSpec = CheckSpec {
+    csFilename = "",
+    csScript = "",
+    csExcludedWarnings = [],
+    csShellTypeOverride = Nothing
+}
+
+-- Parser input and output
+data ParseSpec = ParseSpec {
+    psFilename :: String,
+    psScript :: String
+} deriving (Show, Eq)
+
+data ParseResult = ParseResult {
+    prComments :: [PositionedComment],
+    prTokenPositions :: Map.Map Id Position,
+    prRoot :: Maybe Token
+} deriving (Show, Eq)
+
+-- Analyzer input and output
+data AnalysisSpec = AnalysisSpec {
+    asScript :: Token,
+    asShellType :: Maybe Shell,
+    asExecutionMode :: ExecutionMode
+}
+
+data AnalysisResult = AnalysisResult {
+    arComments :: [TokenComment]
+}
+
+
+-- Formatter options
+data FormatterOptions = FormatterOptions {
+    foColorOption :: ColorOption
+}
+
+
+-- Supporting data types
+data Shell = Ksh | Sh | Bash | Dash deriving (Show, Eq)
+data ExecutionMode = Executed | Sourced deriving (Show, Eq)
+
+type ErrorMessage = String
+type Code = Integer
+
+data Severity = ErrorC | WarningC | InfoC | StyleC deriving (Show, Eq, Ord)
+data Position = Position {
+    posFile :: String,    -- Filename
+    posLine :: Integer,   -- 1 based source line
+    posColumn :: Integer  -- 1 based source column, where tabs are 8
+} deriving (Show, Eq)
+
+data Comment = Comment Severity Code String deriving (Show, Eq)
+data PositionedComment = PositionedComment Position Comment deriving (Show, Eq)
+data TokenComment = TokenComment Id Comment deriving (Show, Eq)
+
+data ColorOption =
+    ColorAuto
+    | ColorAlways
+    | ColorNever
+  deriving (Ord, Eq, Show)
+
+-- For testing
+mockedSystemInterface :: [(String, String)] -> SystemInterface Identity
+mockedSystemInterface files = SystemInterface {
+    siReadFile = rf
+}
+  where
+    rf file =
+        case filter ((== file) . fst) files of
+            [] -> return $ Left "File not included in mock."
+            [(_, contents)] -> return $ Right contents
+

ShellCheck/Options.hs

@@ -1,14 +0,0 @@
-module ShellCheck.Options where
-
-data Shell = Ksh | Zsh | Sh | Bash
-    deriving (Show, Eq)
-
-data AnalysisOptions = AnalysisOptions {
-    optionShellType :: Maybe Shell,
-    optionExcludes :: [Integer]
-}
-
-defaultAnalysisOptions = AnalysisOptions {
-    optionShellType = Nothing,
-    optionExcludes = []
-}

ShellCheck/Regex.hs

@@ -0,0 +1,80 @@
+{-
+    Copyright 2012-2015 Vidar Holen
+
+    This file is part of ShellCheck.
+    http://www.vidarholen.net/contents/shellcheck
+
+    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 <http://www.gnu.org/licenses/>.
+-}
+{-# LANGUAGE FlexibleContexts #-}
+
+-- Basically Text.Regex based on regex-tdfa instead of the buggy regex-posix.
+module ShellCheck.Regex where
+
+import Data.List
+import Data.Maybe
+import Control.Monad
+import Text.Regex.TDFA
+
+-- Precompile the regex
+mkRegex :: String -> Regex
+mkRegex str =
+    let make :: RegexMaker Regex CompOption ExecOption String => String -> Regex
+        make = makeRegex
+    in
+        make str
+
+-- Does the regex match?
+matches :: String -> Regex -> Bool
+matches = flip match
+
+-- Get all subgroups of the first match
+matchRegex :: Regex -> String -> Maybe [String]
+matchRegex re str = do
+    (_, _, _, groups) <- matchM re str :: Maybe (String,String,String,[String])
+    return groups
+
+-- Get all full matches
+matchAllStrings :: Regex -> String -> [String]
+matchAllStrings re = unfoldr f
+  where
+    f :: String -> Maybe (String, String)
+    f str = do
+        (_, match, rest, _) <- matchM re str :: Maybe (String, String, String, [String])
+        return (match, rest)
+
+-- Get all subgroups from all matches
+matchAllSubgroups :: Regex -> String -> [[String]]
+matchAllSubgroups re = unfoldr f
+  where
+    f :: String -> Maybe ([String], String)
+    f str = do
+        (_, _, rest, groups) <- matchM re str :: Maybe (String, String, String, [String])
+        return (groups, rest)
+
+-- Replace regex in input with string
+subRegex :: Regex -> String -> String -> String
+subRegex re input replacement = f input
+  where
+    f str = fromMaybe str $ do
+        (before, match, after) <- matchM re str :: Maybe (String, String, String)
+        when (null match) $ error ("Internal error: substituted empty in " ++ str)
+        return $ before ++ replacement ++ f after
+
+-- Split a string based on a regex.
+splitOn :: String -> Regex -> [String]
+splitOn input re =
+    case matchM re input :: Maybe (String, String, String) of
+        Just (before, match, after) -> before : after `splitOn` re
+        Nothing -> [input]

ShellCheck/Simple.hs

@@ -1,77 +0,0 @@
-{-
-    This file is part of ShellCheck.
-    http://www.vidarholen.net/contents/shellcheck
-
-    ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero 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 Affero General Public License for more details.
-
-    You should have received a copy of the GNU Affero General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
--}
-{-# LANGUAGE TemplateHaskell #-}
-module ShellCheck.Simple (shellCheck, ShellCheckComment, scLine, scColumn, scSeverity, scCode, scMessage, runTests) where
-
-import Data.List
-import Data.Maybe
-import ShellCheck.Analytics hiding (runTests)
-import ShellCheck.Options
-import ShellCheck.Parser hiding (runTests)
-import Test.QuickCheck.All (quickCheckAll)
-import Text.Parsec.Pos
-
-shellCheck :: AnalysisOptions -> String -> [ShellCheckComment]
-shellCheck options script =
-    let (ParseResult result notes) = parseShell "-" script in
-        let allNotes = notes ++ concat (maybeToList $ do
-            (tree, posMap) <- result
-            let list = runAnalytics options tree
-            return $ map (noteToParseNote posMap) $ filterByAnnotation tree list
-            )
-        in
-            map formatNote $ nub $ sortNotes allNotes
-
-data ShellCheckComment = ShellCheckComment { scLine :: Int, scColumn :: Int, scSeverity :: String, scCode :: Int, scMessage :: String }
-
-instance Show ShellCheckComment where
-    show c = concat ["(", show $ scLine c, ",", show $ scColumn c, ") ", scSeverity c, ": ", show (scCode c), " ", scMessage c]
-
-severityToString s =
-    case s of
-        ErrorC -> "error"
-        WarningC -> "warning"
-        InfoC -> "info"
-        StyleC -> "style"
-
-formatNote (ParseNote pos severity code text) =
-    ShellCheckComment (sourceLine pos) (sourceColumn pos) (severityToString severity) (fromIntegral code) text
-
-testCheck = shellCheck defaultAnalysisOptions { optionExcludes = [2148] } -- Ignore #! warnings
-prop_findsParseIssue =
-    let comments = testCheck "echo \"$12\"" in
-        length comments == 1 && scCode (head comments) == 1037
-prop_commentDisablesParseIssue1 =
-    null $ testCheck "#shellcheck disable=SC1037\necho \"$12\""
-prop_commentDisablesParseIssue2 =
-    null $ testCheck "#shellcheck disable=SC1037\n#lol\necho \"$12\""
-
-prop_findsAnalysisIssue =
-    let comments = testCheck "echo $1" in
-        length comments == 1 && scCode (head comments) == 2086
-prop_commentDisablesAnalysisIssue1 =
-    null $ testCheck "#shellcheck disable=SC2086\necho $1"
-prop_commentDisablesAnalysisIssue2 =
-    null $ testCheck "#shellcheck disable=SC2086\n#lol\necho $1"
-
-prop_optionDisablesIssue1 =
-    null $ shellCheck (defaultAnalysisOptions { optionExcludes = [2086, 2148] }) "echo $1"
-
-return []
-runTests = $quickCheckAll
-

quickrun

@@ -0,0 +1,5 @@
+#!/bin/bash
+# quickrun runs ShellCheck in an interpreted mode.
+# This allows testing changes without recompiling.
+
+runghc -idist/build/autogen shellcheck.hs "$@"

quicktest

@@ -0,0 +1,21 @@
+#!/bin/bash
+# quicktest runs the ShellCheck unit tests in an interpreted mode.
+# This allows running tests without compiling, which can be faster.
+# 'cabal test' remains the source of truth.
+
+(
+ var=$(echo 'liftM and $ sequence [
+  ShellCheck.Analytics.runTests
+  ,ShellCheck.Parser.runTests
+  ,ShellCheck.Checker.runTests
+  ,ShellCheck.Checks.Commands.runTests
+  ,ShellCheck.AnalyzerLib.runTests
+    ]' | tr -d '\n' | cabal repl 2>&1 | tee /dev/stderr)
+if [[ $var == *$'\nTrue'* ]]
+then
+  exit 0
+else
+  grep -C 3 -e "Fail" -e "Tracing" <<< "$var"
+  exit 1
+fi
+) 2>&1

shellcheck.1.md

@@ -16,8 +16,28 @@ errors and pitfalls where the shell just gives a cryptic error message or
 strange behavior, but it also reports on a few more advanced issues where
 corner cases can cause delayed failures.
 
+ShellCheck gives shell specific advice. Consider this line:
+
+    (( area = 3.14*r*r ))
+
++ For scripts starting with `#!/bin/sh` (or when using `-s sh`), ShellCheck
+will warn that `(( .. ))` is not POSIX compliant (similar to checkbashisms).
+
++ For scripts starting with `#!/bin/bash` (or using `-s bash`), ShellCheck
+will warn that decimals are not supported.
+
++ For scripts starting with `#!/bin/ksh` (or using `-s ksh`), ShellCheck will
+not warn at all, as `ksh` supports decimals in arithmetic contexts.
+
+
 # OPTIONS
 
+**-C**[*WHEN*],\ **--color**[=*WHEN*]
+
+:   For TTY output, enable colors *always*, *never* or *auto*. The default
+    is *auto*. **--color** without an argument is equivalent to
+    **--color=always**.
+
 **-e**\ *CODE1*[,*CODE2*...],\ **--exclude=***CODE1*[,*CODE2*...]
 
 :   Explicitly exclude the specified codes from the report. Subsequent **-e**
@@ -32,13 +52,20 @@ corner cases can cause delayed failures.
 
 **-s**\ *shell*,\ **--shell=***shell*
 
-:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *ksh* and
-    *zsh*. The default is to use the file's shebang, or *bash* if the target
-    shell can't be determined.
+:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *dash* and *ksh*.
+    The default is to use the file's shebang, or *bash* if the target shell
+    can't be determined.
 
-**-V**\ *version*,\ **--version**
+**-V**,\ **--version**
 
-:   Print version and exit.
+:   Print version information and exit.
+
+**-x**,\ **--external-sources**
+
+:   Follow 'source' statements even when the file is not specified as input.
+    By default, `shellcheck` will only follow files specified on the command
+    line (plus `/dev/null`). This option allows following any file the script
+    may `source`.
 
 # FORMATS
 
@@ -83,11 +110,12 @@ corner cases can cause delayed failures.
 
         [
           {
-            "line": line,
-            "column": column,
-            "level": level,
-            "code": ####,
-            "message": message
+            "file": "filename",
+            "line": lineNumber,
+            "column": columnNumber,
+            "level": "severitylevel",
+            "code": errorCode,
+            "message": "warning message"
           },
           ...
         ]
@@ -104,6 +132,19 @@ For example, to suppress SC2035 about using `./*.jpg`:
     # shellcheck disable=SC2035
     echo "Files: " *.jpg
 
+To tell ShellCheck where to look for an otherwise dynamically determined file:
+
+    # shellcheck source=./lib.sh
+    source "$(find_install_dir)/lib.sh"
+
+Here a shell brace group is used to suppress a warning on multiple lines:
+
+    # shellcheck disable=SC2016
+    {
+      echo 'Modifying $PATH'
+      echo 'PATH=foo:$PATH' >> ~/.bashrc
+    }
+
 Valid keys are:
 
 **disable**
@@ -111,6 +152,28 @@ 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.
 
+**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
+    at runtime, or to skip a source by telling it to use `/dev/null`.
+
+# ENVIRONMENT VARIABLES
+The environment variable `SHELLCHECK_OPTS` can be set with default flags:
+
+    export SHELLCHECK_OPTS='--shell=bash --exclude=SC2016'
+
+Its value will be split on spaces and prepended to the command line on each
+invocation.
+
+# RETURN VALUES
+
+ShellCheck uses the follow exit codes:
+
++ 0: All files successfully scanned with no issues.
++ 1: All files successfully scanned with some issues.
++ 2: Some files could not be processed (e.g. file not found).
++ 3: ShellCheck was invoked with bad syntax (e.g. unknown flag).
++ 4: ShellCheck was invoked with bad options (e.g. unknown formatter).
 
 # AUTHOR
 ShellCheck is written and maintained by Vidar Holen.
@@ -120,6 +183,12 @@ Bugs and issues can be reported on GitHub:
 
 https://github.com/koalaman/shellcheck/issues
 
+# COPYRIGHT
+Copyright 2012-2015, Vidar Holen.
+Licensed under the GNU General Public License version 3 or later,
+see http://gnu.org/licenses/gpl.html
+
+
 # SEE ALSO
 
 sh(1) bash(1)

shellcheck.hs

@@ -1,254 +1,111 @@
 {-
+    Copyright 2012-2015 Vidar Holen
+
     This file is part of ShellCheck.
     http://www.vidarholen.net/contents/shellcheck
 
     ShellCheck is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published by
+    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 Affero General Public License for more details.
+    GNU General Public License for more details.
 
-    You should have received a copy of the GNU Affero General Public License
+    You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 -}
+import ShellCheck.Data
+import ShellCheck.Checker
+import ShellCheck.Interface
+import ShellCheck.Regex
+
+import ShellCheck.Formatter.Format
+import qualified ShellCheck.Formatter.CheckStyle
+import qualified ShellCheck.Formatter.GCC
+import qualified ShellCheck.Formatter.JSON
+import qualified ShellCheck.Formatter.TTY
+
 import Control.Exception
 import Control.Monad
-import Control.Monad.Trans
-import Control.Monad.Trans.Error
+import Control.Monad.Except
 import Data.Char
+import Data.Functor
+import Data.Either
+import qualified Data.Map as Map
 import Data.Maybe
 import Data.Monoid
-import GHC.Exts
-import GHC.IO.Device
 import Prelude hiding (catch)
-import ShellCheck.Data
-import ShellCheck.Options
-import ShellCheck.Simple
-import ShellCheck.Analytics
 import System.Console.GetOpt
 import System.Directory
 import System.Environment
 import System.Exit
 import System.IO
-import Text.JSON
-import qualified Data.Map as Map
 
 data Flag = Flag String String
-data Status = NoProblems | SomeProblems | BadInput | SupportFailure | SyntaxFailure | RuntimeException deriving (Ord, Eq)
-
-instance Error Status where
-    noMsg = RuntimeException
+data Status =
+    NoProblems
+    | SomeProblems
+    | SupportFailure
+    | SyntaxFailure
+    | RuntimeException
+  deriving (Ord, Eq, Show)
 
 instance Monoid Status where
     mempty = NoProblems
     mappend = max
 
-header = "Usage: shellcheck [OPTIONS...] FILES..."
+data Options = Options {
+    checkSpec :: CheckSpec,
+    externalSources :: Bool,
+    formatterOptions :: FormatterOptions
+}
+
+defaultOptions = Options {
+    checkSpec = emptyCheckSpec,
+    externalSources = False,
+    formatterOptions = FormatterOptions {
+        foColorOption = ColorAuto
+    }
+}
+
+usageHeader = "Usage: shellcheck [OPTIONS...] FILES..."
 options = [
     Option "e" ["exclude"]
         (ReqArg (Flag "exclude") "CODE1,CODE2..") "exclude types of warnings",
     Option "f" ["format"]
         (ReqArg (Flag "format") "FORMAT") "output format",
+    Option "C" ["color"]
+        (OptArg (maybe (Flag "color" "always") (Flag "color")) "WHEN")
+        "Use color (auto, always, never)",
     Option "s" ["shell"]
-        (ReqArg (Flag "shell") "SHELLNAME") "Specify dialect (bash,sh,ksh,zsh)",
+        (ReqArg (Flag "shell") "SHELLNAME") "Specify dialect (sh,bash,dash,ksh)",
+    Option "x" ["external-sources"]
+        (NoArg $ Flag "externals" "true") "Allow 'source' outside of FILES.",
     Option "V" ["version"]
         (NoArg $ Flag "version" "true") "Print version information"
     ]
 
-printErr = hPutStrLn stderr
+printErr = lift . hPutStrLn stderr
 
-
-instance JSON ShellCheckComment where
-  showJSON c = makeObj [
-      ("line", showJSON $ scLine c),
-      ("column", showJSON $ scColumn c),
-      ("level", showJSON $ scSeverity c),
-      ("code", showJSON $ scCode c),
-      ("message", showJSON $ scMessage c)
-      ]
-  readJSON = undefined
-
-parseArguments :: [String] -> ErrorT Status IO ([Flag], [FilePath])
+parseArguments :: [String] -> ExceptT Status IO ([Flag], [FilePath])
 parseArguments argv =
     case getOpt Permute options argv of
         (opts, files, []) -> return (opts, files)
         (_, _, errors) -> do
-            liftIO . printErr $ concat errors ++ "\n" ++ usageInfo header options
+            printErr $ concat errors ++ "\n" ++ usageInfo usageHeader options
             throwError SyntaxFailure
 
-formats :: Map.Map String (AnalysisOptions -> [FilePath] -> IO Status)
-formats = Map.fromList [
-    ("json", forJson),
-    ("gcc", forGcc),
-    ("checkstyle", forCheckstyle),
-    ("tty", forTty)
+formats :: FormatterOptions -> Map.Map String (IO Formatter)
+formats options = Map.fromList [
+    ("checkstyle", ShellCheck.Formatter.CheckStyle.format),
+    ("gcc",  ShellCheck.Formatter.GCC.format),
+    ("json", ShellCheck.Formatter.JSON.format),
+    ("tty",  ShellCheck.Formatter.TTY.format options)
     ]
 
-toStatus = liftM (either id (const NoProblems)) . runErrorT
-
-catchExceptions :: IO Status -> IO Status
-catchExceptions action = action -- action `catch` handler
-  where
-    handler err = do
-        printErr $ show (err :: SomeException)
-        return RuntimeException
-
-checkComments comments = if null comments then NoProblems else SomeProblems
-
-forTty :: AnalysisOptions -> [FilePath] -> IO Status
-forTty options files = do
-    output <- mapM doFile files
-    return $ mconcat output
-  where
-    clear = ansi 0
-    ansi n = "\x1B[" ++ show n ++ "m"
-
-    colorForLevel "error" = 31 -- red
-    colorForLevel "warning" = 33 -- yellow
-    colorForLevel "info" = 32 -- green
-    colorForLevel "style" = 32 -- green
-    colorForLevel "message" = 1 -- bold
-    colorForLevel "source" = 0 -- none
-    colorForLevel _ = 0 -- none
-
-    colorComment level comment =
-        ansi (colorForLevel level) ++ comment ++ clear
-
-    doFile path = catchExceptions $ do
-        contents <- readContents path
-        doInput path contents
-
-    doInput filename contents = do
-        let fileLines = lines contents
-        let lineCount = length fileLines
-        let comments = getComments options contents
-        let groups = groupWith scLine comments
-        colorFunc <- getColorFunc
-        mapM_ (\x -> do
-            let lineNum = scLine (head x)
-            let line = if lineNum < 1 || lineNum > lineCount
-                            then ""
-                            else fileLines !! (lineNum - 1)
-            putStrLn ""
-            putStrLn $ colorFunc "message"
-                ("In " ++ filename ++" line " ++ show lineNum ++ ":")
-            putStrLn (colorFunc "source" line)
-            mapM_ (\c -> putStrLn (colorFunc (scSeverity c) $ cuteIndent c)) x
-            putStrLn ""
-          ) groups
-        return . checkComments $ comments
-
-    cuteIndent comment =
-        replicate (scColumn comment - 1) ' ' ++
-            "^-- " ++ code (scCode comment) ++ ": " ++ scMessage comment
-
-    code code = "SC" ++ show code
-
-    getColorFunc = do
-        term <- hIsTerminalDevice stdout
-        return $ if term then colorComment else const id
-
--- This totally ignores the filenames. Fixme?
-forJson :: AnalysisOptions -> [FilePath] -> IO Status
-forJson options files = catchExceptions $ do
-    comments <- liftM concat $ mapM (commentsFor options) files
-    putStrLn $ encodeStrict comments
-    return $ checkComments comments
-
--- Mimic GCC "file:line:col: (error|warning|note): message" format
-forGcc :: AnalysisOptions -> [FilePath] -> IO Status
-forGcc options files = do
-    files <- mapM process files
-    return $ mconcat files
-  where
-    process file = catchExceptions $ do
-        contents <- readContents file
-        let comments = makeNonVirtual (getComments options contents) contents
-        mapM_ (putStrLn . format file) comments
-        return $ checkComments comments
-
-    format filename c = concat [
-            filename, ":",
-            show $ scLine c, ":",
-            show $ scColumn c, ": ",
-            case scSeverity c of
-                "error" -> "error"
-                "warning" -> "warning"
-                _ -> "note",
-            ": ",
-            concat . lines $ scMessage c,
-            " [SC", show $ scCode c, "]"
-      ]
-
--- Checkstyle compatible output. A bit of a hack to avoid XML dependencies
-forCheckstyle :: AnalysisOptions -> [FilePath] -> IO Status
-forCheckstyle options files = do
-    putStrLn "<?xml version='1.0' encoding='UTF-8'?>"
-    putStrLn "<checkstyle version='4.3'>"
-    statuses <- mapM process files
-    putStrLn "</checkstyle>"
-    return $ mconcat statuses
-  where
-    process file = catchExceptions $ do
-        comments <- commentsFor options file
-        putStrLn (formatFile file comments)
-        return $ checkComments comments
-
-    severity "error" = "error"
-    severity "warning" = "warning"
-    severity _ = "info"
-    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` " ./")]
-
-    formatFile name comments = concat [
-        "<file ", attr "name" name, ">\n",
-            concatMap format comments,
-        "</file>"
-        ]
-
-    format c = concat [
-        "<error ",
-        attr "line" $ show . scLine $ c,
-        attr "column" $ show . scColumn $ c,
-        attr "severity" $ severity . scSeverity $ c,
-        attr "message" $ scMessage c,
-        attr "source" $ "ShellCheck.SC" ++ show (scCode c),
-        "/>\n"
-        ]
-
-commentsFor options file = liftM (getComments options) $ readContents file
-
-getComments = shellCheck
-
-readContents :: FilePath -> IO String
-readContents file =
-    if file == "-"
-    then getContents
-    else readFile file
-
--- Realign comments from a tabstop of 8 to 1
-makeNonVirtual comments contents =
-    map fix comments
-  where
-    ls = lines contents
-    fix c = c {
-        scColumn =
-            if scLine c > 0 && scLine c <= length ls
-            then real (ls !! (scLine c - 1)) 0 0 (scColumn c)
-            else scColumn c
-    }
-    real _ r v target | target <= v = r
-    real [] r v _ = r -- should never happen
-    real ('\t':rest) r v target =
-        real rest (r+1) (v + 8 - (v `mod` 8)) target
-    real (_:rest) r v target = real rest (r+1) (v+1) target
-
 getOption [] _ = Nothing
 getOption (Flag var val:_) name | name == var = return val
 getOption (_:rest) flag = getOption rest flag
@@ -271,13 +128,19 @@ getExclusions options =
     in
         map (Prelude.read . clean) elements :: [Int]
 
-excludeCodes codes =
-    filter (not . hasCode)
+toStatus = liftM (either id id) . runExceptT
+
+getEnvArgs = do
+    opts <- getEnv "SHELLCHECK_OPTS" `catch` cantWaitForLookupEnv
+    return . filter (not . null) $ opts `splitOn` mkRegex " +"
   where
-    hasCode c = scCode c `elem` codes
+    cantWaitForLookupEnv :: IOException -> IO String
+    cantWaitForLookupEnv = const $ return ""
 
 main = do
-    args <- getArgs
+    params <- getArgs
+    envOpts  <- getEnvArgs
+    let args = envOpts ++ params
     status <- toStatus $ do
         (flags, files) <- parseArguments args
         process flags files
@@ -287,62 +150,160 @@ statusToCode status =
     case status of
         NoProblems -> ExitSuccess
         SomeProblems -> ExitFailure 1
-        BadInput -> ExitFailure 5
         SyntaxFailure -> ExitFailure 3
         SupportFailure -> ExitFailure 4
         RuntimeException -> ExitFailure 2
 
-process :: [Flag] -> [FilePath] -> ErrorT Status IO ()
+process :: [Flag] -> [FilePath] -> ExceptT Status IO Status
 process flags files = do
-    options <- foldM (flip parseOption) defaultAnalysisOptions flags
+    options <- foldM (flip parseOption) defaultOptions flags
     verifyFiles files
     let format = fromMaybe "tty" $ getOption flags "format"
-    case Map.lookup format formats of
-        Nothing -> do
-            liftIO $ do
+    let formatters = formats $ formatterOptions options
+    formatter <-
+        case Map.lookup format formatters of
+            Nothing -> do
                 printErr $ "Unknown format " ++ format
                 printErr "Supported formats:"
-                mapM_ (printErr . write) $ Map.keys formats
-            throwError SupportFailure
-          where write s = "  " ++ s
-        Just f -> ErrorT $ liftM Left $ f options files
+                mapM_ (printErr . write) $ Map.keys formatters
+                throwError SupportFailure
+              where write s = "  " ++ s
+            Just f -> ExceptT $ fmap Right f
+    sys <- lift $ ioInterface options files
+    lift $ runFormatter sys formatter options files
+
+runFormatter :: SystemInterface IO -> Formatter -> Options -> [FilePath]
+            -> IO Status
+runFormatter sys format options files = do
+    header format
+    result <- foldM f NoProblems files
+    footer format
+    return result
+  where
+    f :: Status -> FilePath -> IO Status
+    f status file = do
+        newStatus <- process file `catch` handler file
+        return $ status `mappend` newStatus
+    handler :: FilePath -> IOException -> IO Status
+    handler file e = do
+        onFailure format file (show e)
+        return RuntimeException
+
+    process :: FilePath -> IO Status
+    process filename = do
+        contents <- inputFile filename
+        let checkspec = (checkSpec options) {
+            csFilename = filename,
+            csScript = contents
+        }
+        result <- checkScript sys checkspec
+        onResult format result contents
+        return $
+            if null (crComments result)
+            then NoProblems
+            else SomeProblems
+
+parseColorOption colorOption =
+    case colorOption of
+        "auto" -> ColorAuto
+        "always" -> ColorAlways
+        "never" -> ColorNever
+        _ -> error $ "Bad value for --color `" ++ colorOption ++ "'"
 
 parseOption flag options =
     case flag of
         Flag "shell" str ->
-                fromMaybe (die $ "Unknown shell: " ++ str) $ do
-                    shell <- shellForExecutable str
-                    return $ return options { optionShellType = Just shell }
+            fromMaybe (die $ "Unknown shell: " ++ str) $ do
+                shell <- shellForExecutable str
+                return $ return options {
+                            checkSpec = (checkSpec options) {
+                                csShellTypeOverride = Just shell
+                            }
+                        }
 
         Flag "exclude" str -> do
             new <- mapM parseNum $ split ',' str
-            let old = optionExcludes options
-            return options { optionExcludes = new ++ old }
+            let old = csExcludedWarnings . checkSpec $ options
+            return options {
+                checkSpec = (checkSpec options) {
+                    csExcludedWarnings = new ++ old
+                }
+            }
 
         Flag "version" _ -> do
             liftIO printVersion
             throwError NoProblems
 
+        Flag "externals" _ ->
+            return options {
+                externalSources = True
+            }
+
+        Flag "color" color ->
+            return options {
+                formatterOptions = (formatterOptions options) {
+                    foColorOption = parseColorOption color
+                }
+            }
+
         _ -> return options
   where
     die s = do
-        liftIO $ printErr s
+        printErr s
         throwError SupportFailure
     parseNum ('S':'C':str) = parseNum str
     parseNum num = do
         unless (all isDigit num) $ do
-            liftIO . printErr $ "Bad exclusion: " ++ num
+            printErr $ "Bad exclusion: " ++ num
             throwError SyntaxFailure
         return (Prelude.read num :: Integer)
 
+ioInterface options files = do
+    inputs <- mapM normalize files
+    return SystemInterface {
+        siReadFile = get inputs
+    }
+  where
+    get inputs file = do
+        ok <- allowable inputs file
+        if ok
+          then (Right <$> inputFile file) `catch` handler
+          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 =
+        if externalSources options
+        then return True
+        else do
+            path <- normalize x
+            return $ path `elem` inputs
+
+    normalize x =
+        canonicalizePath x `catch` fallback x
+      where
+        fallback :: FilePath -> IOException -> IO FilePath
+        fallback path _ = return path
+
+inputFile file = do
+    contents <-
+            if file == "-"
+            then getContents
+            else readFile file
+
+    seq (length contents) $
+        return contents
+
 verifyFiles files =
     when (null files) $ do
-        liftIO $ printErr "No files specified.\n"
-        liftIO $ printErr $ usageInfo header options
+        printErr "No files specified.\n"
+        printErr $ usageInfo usageHeader options
         throwError SyntaxFailure
 
 printVersion = do
     putStrLn   "ShellCheck - shell script analysis tool"
     putStrLn $ "version: " ++ shellcheckVersion
-    putStrLn   "license: GNU Affero General Public License, version 3"
+    putStrLn   "license: GNU General Public License, version 3"
     putStrLn   "website: http://www.shellcheck.net"

stack.yaml

@@ -0,0 +1,35 @@
+# This file was automatically generated by stack init
+# For more information, see: http://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-5.5
+
+# Local packages, usually specified by relative directory name
+packages:
+- '.'
+# Packages to be pulled from upstream that are not in the resolver (e.g., acme-missiles-0.3)
+extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+flags: {}
+
+# Extra package databases containing global packages
+extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: >= 1.0.0
+
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor

test/shellcheck.hs

@@ -2,15 +2,21 @@ module Main where
 
 import Control.Monad
 import System.Exit
-import qualified ShellCheck.Simple
+import qualified ShellCheck.Checker
 import qualified ShellCheck.Analytics
+import qualified ShellCheck.AnalyzerLib
 import qualified ShellCheck.Parser
+import qualified ShellCheck.Checks.Commands
 
 main = do
     putStrLn "Running ShellCheck tests..."
-    results <- sequence [ShellCheck.Simple.runTests,
-                         ShellCheck.Analytics.runTests,
-                         ShellCheck.Parser.runTests]
-    if and results then exitSuccess
-     else exitFailure
-
+    results <- sequence [
+        ShellCheck.Checker.runTests,
+        ShellCheck.Checks.Commands.runTests,
+        ShellCheck.Analytics.runTests,
+        ShellCheck.AnalyzerLib.runTests,
+        ShellCheck.Parser.runTests
+      ]
+    if and results
+      then exitSuccess
+      else exitFailure