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shellcheck

shellcheck documentation

shellcheck - GitHub

Configuration in Mega-Linter

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_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_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 Install in VsCode

Mega-Linter Flavours

This linter is available in the following flavours

Flavor Description Embedded linters Info
all Default Mega-Linter Flavor 91 Docker Image Size (tag) Docker Pulls
dart Optimized for DART based projects 39 Docker Image Size (tag) Docker Pulls
documentation Mega-Linter for documentation projects 38 Docker Image Size (tag) Docker Pulls
dotnet Optimized for C, C++, C# or VB based projects 44 Docker Image Size (tag) Docker Pulls
go Optimized for GO based projects 40 Docker Image Size (tag) Docker Pulls
java Optimized for JAVA based projects 39 Docker Image Size (tag) Docker Pulls
javascript Optimized for JAVASCRIPT or TYPESCRIPT based projects 47 Docker Image Size (tag) Docker Pulls
php Optimized for PHP based projects 42 Docker Image Size (tag) Docker Pulls
python Optimized for PYTHON based projects 47 Docker Image Size (tag) Docker Pulls
ruby Optimized for RUBY based projects 39 Docker Image Size (tag) Docker Pulls
rust Optimized for RUST based projects 39 Docker Image Size (tag) Docker Pulls
salesforce Optimized for Salesforce based projects 41 Docker Image Size (tag) Docker Pulls
scala Optimized for SCALA based projects 39 Docker Image Size (tag) Docker Pulls
swift Optimized for SWIFT based projects 39 Docker Image Size (tag) Docker Pulls
terraform Optimized for TERRAFORM based projects 43 Docker Image Size (tag) Docker Pulls

Behind the scenes

How are identified applicable files

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

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://nvuillam.github.io/mega-linter/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://nvuillam.github.io/mega-linter/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...