Merge pull request #1026 from PeterDaveHello/patch-1

Enable syntax highlight in README.md code block

README.md

@@ -148,8 +148,10 @@ On Solus:
 
 From Docker Hub:
 
+```sh
 docker pull koalaman/shellcheck:latest  # Or  :v0.4.6  for a release version
 docker run -v "$PWD:/mnt" koalaman/shellcheck myscript
+```
 
 or use `koalaman/shellcheck-alpine` if you want a larger Alpine Linux based image to extend.
 
@@ -209,12 +211,16 @@ This will compile ShellCheck and install it to your `~/.cabal/bin` directory.
 
 Add this directory to your `PATH` (for bash, add this to your `~/.bashrc`):
 
+```sh
 export PATH="$HOME/.cabal/bin:$PATH"
+```
 
 Log out and in again, and verify that your PATH is set up correctly:
 
+```sh
 $ which shellcheck
 ~/.cabal/bin/shellcheck
+```
 
 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,
@@ -242,6 +248,7 @@ So what kind of things does ShellCheck look for? Here is an incomplete list of d
 
 ShellCheck can recognize several types of incorrect quoting:
 
+```sh
 echo $1                           # Unquoted variables
 find . -name *.ogg                # Unquoted find/grep patterns
 rm "~/my file.txt"                # Quoted tilde expansion
@@ -252,11 +259,13 @@ ShellCheck can recognize several types of incorrect quoting:
 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.
 
+```sh
 [[ n != 0 ]]                      # Constant test expressions
 [[ -e *.mpg ]]                    # Existence checks of globs
 [[ $foo==0 ]]                     # Always true due to missing spaces
@@ -268,11 +277,13 @@ ShellCheck can recognize many types of incorrect test statements.
 [ grep -q foo file ]              # Command without $(..)
 [[ "$$file" == *.jpg ]]           # Comparisons that can't succeed
 (( 1 -lt 2 ))                     # Using test operators in ((..))
+```
 
 ### Frequently misused commands
 
 ShellCheck can recognize instances where commands are used incorrectly:
 
+```sh
 grep '*foo*' file                 # Globs in regex contexts
 find . -exec foo {} && bar {} \;  # Prematurely terminated find -exec
 sudo echo 'Var=42' > /etc/profile # Redirecting sudo
@@ -283,11 +294,13 @@ ShellCheck can recognize instances where commands are used incorrectly:
 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:
 
+```sh
 var = 42                          # Spaces around = in assignments
 $foo=42                           # $ in assignments
 for $var in *; do ...             # $ in for loop variables
@@ -298,11 +311,13 @@ ShellCheck recognizes many common beginner's syntax errors:
 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:
 
+```sh
 [[ -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
@@ -311,11 +326,13 @@ ShellCheck can make suggestions to improve style:
 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:
 
+```sh
 args="$@"                         # Assigning arrays to strings
 files=(foo bar); echo "$files"    # Referencing arrays as strings
 declare -A arr=(foo bar)          # Associative arrays without index
@@ -324,22 +341,26 @@ ShellCheck can recognize issues related to data and typing:
 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:
 
+```sh
 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`:
 
+```sh
 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
@@ -350,11 +371,13 @@ ShellCheck will warn when using features not supported by the shebang. For examp
 [ $UID = 0 ]                     # Variable undefined in dash/sh
 local var=value                  # local is undefined in sh
 time sleep 1 | sleep 5           # Undefined uses of 'time'
+```
 
 ### Miscellaneous
 
 ShellCheck recognizes a menagerie of other issues:
 
+```sh
 PS1='\e[0;32m\$\e[0m '            # PS1 colors not in \[..\]
 PATH="$PATH:~/bin"                # Literal tilde in $PATH
 rm “file”                         # Unicode quotes
@@ -365,6 +388,7 @@ ShellCheck recognizes a menagerie of other issues:
 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