shellcheck

shellcheck documentation

Version in Mega-Linter: 0.7.2
Visit Official Web Site
See How to disable shellcheck rules in files
See Index of problems detected by shellcheck

Configuration in Mega-Linter

Enable shellcheck by adding BASH_SHELLCHECK in ENABLE_LINTERS variable
Disable shellcheck by adding BASH_SHELLCHECK in DISABLE_LINTERS variable

Variable	Description	Default value
BASH_SHELLCHECK_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
BASH_SHELLCHECK_FILTER_REGEX_INCLUDE	Custom regex including filter Ex: `(src\\|lib)`	Include every file
BASH_SHELLCHECK_FILTER_REGEX_EXCLUDE	Custom regex excluding filter Ex: `(test\\|examples)`	Exclude no file
BASH_SHELLCHECK_CLI_LINT_MODE	Override default CLI lint mode - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`{linter.cli_lint_mode}`
BASH_SHELLCHECK_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".sh", ".bash", ".dash", ".ksh"]`
BASH_SHELLCHECK_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
BASH_SHELLCHECK_PRE_COMMANDS	List of bash commands to run before the linter	None
BASH_SHELLCHECK_POST_COMMANDS	List of bash commands to run after the linter	None
BASH_SHELLCHECK_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
BASH_SHELLCHECK_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`

IDE Integration

Use shellcheck in your favorite IDE to catch errors before Mega-Linter !

IDE	Extension Name	Install
Atom	linter-shellcheck	Visit Web Site
Emacs	flycheck	Visit Web Site
Emacs	flymake-shellcheck	Visit Web Site
Sublime Text	SublimeLinter-shellcheck	Visit Web Site
vim	ale	Visit Web Site
vim	neomake	Visit Web Site
vim	syntastic	Visit Web Site
Visual Studio Code	vscode-shellcheck

Mega-Linter Flavours

This linter is available in the following flavours

Flavor	Description	Embedded linters
all	Default Mega-Linter Flavor	94
dart	Optimized for DART based projects	41
documentation	Mega-Linter for documentation projects	40
dotnet	Optimized for C, C++, C# or VB based projects	47
go	Optimized for GO based projects	42
java	Optimized for JAVA based projects	42
javascript	Optimized for JAVASCRIPT or TYPESCRIPT based projects	49
php	Optimized for PHP based projects	44
python	Optimized for PYTHON based projects	49
ruby	Optimized for RUBY based projects	41
rust	Optimized for RUST based projects	41
salesforce	Optimized for Salesforce based projects	43
scala	Optimized for SCALA based projects	41
swift	Optimized for SWIFT based projects	41
terraform	Optimized for TERRAFORM based projects	45

Behind the scenes

How are identified applicable files

File extensions: .sh, .bash, .dash, .ksh

How the linting is performed

shellcheck is called one time by identified file

Example calls

shellcheck --color=auto --external-sources myfile.sh

Help content

Usage: shellcheck [OPTIONS...] FILES...
  -a                  --check-sourced            Include warnings from sourced files
  -C[WHEN]            --color[=WHEN]             Use color (auto, always, never)
  -i CODE1,CODE2..    --include=CODE1,CODE2..    Consider only given types of warnings
  -e CODE1,CODE2..    --exclude=CODE1,CODE2..    Exclude types of warnings
  -f FORMAT           --format=FORMAT            Output format (checkstyle, diff, gcc, json, json1, quiet, tty)
                      --list-optional            List checks disabled by default
                      --norc                     Don't look for .shellcheckrc files
  -o check1,check2..  --enable=check1,check2..   List of optional checks to enable (or 'all')
  -P SOURCEPATHS      --source-path=SOURCEPATHS  Specify path when looking for sourced files ("SCRIPTDIR" for script's dir)
  -s SHELLNAME        --shell=SHELLNAME          Specify dialect (sh, bash, dash, ksh)
  -S SEVERITY         --severity=SEVERITY        Minimum severity of errors to consider (error, warning, info, style)
  -V                  --version                  Print version information
  -W NUM              --wiki-link-count=NUM      The number of wiki links to show, when applicable
  -x                  --external-sources         Allow 'source' outside of FILES
                      --help                     Show this usage summary and exit

Installation on mega-linter Docker image

Dockerfile commands :

RUN wget -qO- "https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.x86_64.tar.xz" | tar -xJv \
    && cp "shellcheck-stable/shellcheck" /usr/bin/ \
    && shellcheck --version

Example success log

Results of shellcheck linter (version 0.7.1)
See documentation on https://megalinter.github.io/descriptors/bash_shellcheck/
-----------------------------------------------

[SUCCESS] .automation/test/shell/shell_good_1.sh

Example error log

Results of shellcheck linter (version 0.7.1)
See documentation on https://megalinter.github.io/descriptors/bash_shellcheck/
-----------------------------------------------

[ERROR] .automation/test/shell/shell_bad_1.sh

    In .automation/test/shell/shell_bad_1.sh line 10:
    if [ $ERROR_CODE -ne 0]; then
    ^-- SC1009: The mentioned syntax error was in this if expression.
       ^-- SC1073: Couldn't parse this test expression. Fix to allow more checks.
                           ^-- SC1020: You need a space before the ].
                           ^-- SC1072: Missing space before ]. Fix any mentioned problems and try again.

    For more information:
      https://www.shellcheck.net/wiki/SC1020 -- You need a space before the ].
      https://www.shellcheck.net/wiki/SC1072 -- Missing space before ]. Fix any m...
      https://www.shellcheck.net/wiki/SC1073 -- Couldn't parse this test expressi...