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)

Shell script analysis tool                                                                         SHELLCHECK(1)