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shellcheck

shellcheck documentation

shellcheck - GitHub

Configuration in MegaLinter

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
list_of_files
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 MegaLinter !

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

MegaLinter Flavours

This linter is available in the following flavours

Flavor Description Embedded linters Info
all Default MegaLinter Flavor 97 Docker Image Size (tag) Docker Pulls
ci_light Optimized for CI items (Dockerfile, Jenkinsfile, JSON/YAML schemas,XML 16 Docker Image Size (tag) Docker Pulls
dart Optimized for DART based projects 42 Docker Image Size (tag) Docker Pulls
documentation MegaLinter for documentation projects 41 Docker Image Size (tag) Docker Pulls
dotnet Optimized for C, C++, C# or VB based projects 49 Docker Image Size (tag) Docker Pulls
go Optimized for GO based projects 43 Docker Image Size (tag) Docker Pulls
java Optimized for JAVA based projects 43 Docker Image Size (tag) Docker Pulls
javascript Optimized for JAVASCRIPT or TYPESCRIPT based projects 50 Docker Image Size (tag) Docker Pulls
php Optimized for PHP based projects 46 Docker Image Size (tag) Docker Pulls
python Optimized for PYTHON based projects 49 Docker Image Size (tag) Docker Pulls
ruby Optimized for RUBY based projects 42 Docker Image Size (tag) Docker Pulls
rust Optimized for RUST based projects 42 Docker Image Size (tag) Docker Pulls
salesforce Optimized for Salesforce based projects 44 Docker Image Size (tag) Docker Pulls
scala Optimized for SCALA based projects 42 Docker Image Size (tag) Docker Pulls
swift Optimized for SWIFT based projects 42 Docker Image Size (tag) Docker Pulls
terraform Optimized for TERRAFORM based projects 47 Docker Image Size (tag) Docker Pulls

Behind the scenes

How are identified applicable files

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

How the linting is performed

  • shellcheck is called once with the list of files as arguments

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 ML_THIRD_PARTY_DIR="/third-party/shellcheck" \
    && mkdir -p ${ML_THIRD_PARTY_DIR} \
    && wget -qO- "https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.x86_64.tar.xz" | tar -xJv --directory ${ML_THIRD_PARTY_DIR} \
    && mv "${ML_THIRD_PARTY_DIR}/shellcheck-stable/shellcheck" /usr/bin/ \
    && find ${ML_THIRD_PARTY_DIR} -type f -not -name 'LICENSE*' -delete -o -type d -empty -delete \
    && 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...