NAME

       shellcheck - Shell script analysis tool

SYNOPSIS

       shellcheck [OPTIONS...] FILES...

DESCRIPTION

       ShellCheck is a static analysis and linting tool for sh/bash scripts.  It's mainly focused
       on handling typical beginner and intermediate level syntax 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 the 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

       -e CODE1[,CODE2...], --exclude=CODE1[,CODE2...]
              Explicitly  exclude the specified codes from the report.  Subsequent -e options are
              cumulative, but all the codes can be specified at once, comma-separated as a single
              argument.

       -f FORMAT, --format=FORMAT
              Specify  the  output format of shellcheck, which prints its results in the standard
              output.  Subsequent -f options are ignored, see FORMATS below for more information.

       -s shell, --shell=shell
              Specify Bourne shell dialect.  Valid values are sh, bash and ksh.  The  default  is
              to use the file's shebang, or bash if the target shell can't be determined.

       -V version, --version
              Print version and exit.

FORMATS

       tty    Plain text, human readable output.  This is the default.

       gcc    GCC  compatible  output.   Useful  for  editors  that support compiling and showing
              syntax errors.

              For example, in Vim, :set makeprg=shellcheck\ -f\ gcc\ % will allow using :make  to
              check the script, and :cnext to jump to the next error.

                     <file>:<line>:<column>: <type>: <message>

       checkstyle
              Checkstyle  compatible  XML  output.  Supported directly or through plugins by many
              IDEs and build monitoring systems.

                     <?xml version='1.0' encoding='UTF-8'?>
                     <checkstyle version='4.3'>
                       <file name='file'>
                         <error
                           line='line'
                           column='column'
                           severity='severity'
                           message='message'
                           source='ShellCheck.SC####' />
                         ...
                       </file>
                       ...
                     </checkstyle>

       json   Json is a popular serialization format that is more suitable for web  applications.
              ShellCheck's json is compact and contains only the bare minimum.

                     [
                       {
                         "file": "filename",
                         "line": lineNumber,
                         "column": columnNumber,
                         "level": "severitylevel",
                         "code": errorCode,
                         "message": "warning message"
                       },
                       ...
                     ]

DIRECTIVES

       ShellCheck directives can be specified as comments in the shell script before a command or
       block:

              # shellcheck key=value key=value
              command-or-structure

       For example, to suppress SC2035 about using ./*.jpg:

              # shellcheck disable=SC2035
              echo "Files: " *.jpg

       Here a shell brace group is used to suppress on multiple lines:

              # shellcheck disable=SC2016
              {
                echo 'Modifying $PATH'
                echo 'PATH=foo:$PATH' >> ~/.bashrc
              }

       Valid keys are:

       disable
              Disables a comma separated list of error codes  for  the  following  command.   The
              command  can  be  a  simple  command  like  echo foo,  or a compound command like a
              function definition, subshell block or loop.

AUTHOR

       ShellCheck is written and maintained by Vidar Holen.

REPORTING BUGS

       Bugs and issues can be reported on GitHub:

       https://github.com/koalaman/shellcheck/issues

SEE ALSO

       sh(1) bash(1)