Provided by: shellcheck_0.4.6-1_amd64 
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 this 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
-C[WHEN], --color[=WHEN]
For TTY output, enable colors always, never or auto. The default is auto. --color without an
argument is equivalent to --color=always.
-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, dash and ksh. The default is to use the
file's shebang, or bash if the target shell can't be determined.
-V, --version
Print version information and exit.
-x, --external-sources
Follow 'source' statements even when the file is not specified as input. By default, shellcheck
will only follow files specified on the command line (plus /dev/null). This option allows
following any file the script may source.
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
To tell ShellCheck where to look for an otherwise dynamically determined file:
# shellcheck source=./lib.sh
source "$(find_install_dir)/lib.sh"
Here a shell brace group is used to suppress a warning 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.
source Overrides the filename included by a source/. statement. This can be used to tell shellcheck
where to look for a file whose name is determined at runtime, or to skip a source by telling it to
use /dev/null.
ENVIRONMENT VARIABLES
The environment variable SHELLCHECK_OPTS can be set with default flags:
export SHELLCHECK_OPTS='--shell=bash --exclude=SC2016'
Its value will be split on spaces and prepended to the command line on each invocation.
RETURN VALUES
ShellCheck uses the follow exit codes:
• 0: All files successfully scanned with no issues.
• 1: All files successfully scanned with some issues.
• 2: Some files could not be processed (e.g. file not found).
• 3: ShellCheck was invoked with bad syntax (e.g. unknown flag).
• 4: ShellCheck was invoked with bad options (e.g. unknown formatter).
LOCALE
This version of ShellCheck is only available in English. All files are leniently decoded as UTF-8, with
a fallback of ISO-8859-1 for invalid sequences. LC_CTYPE is respected for output, and defaults to UTF-8
for locales where encoding is unspecified (such as the C locale).
Windows users seeing commitBuffer: invalid argument (invalid character) should set their terminal to use
UTF-8 with chcp 65001.
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
COPYRIGHT
Copyright 2012-2015, Vidar Holen. Licensed under the GNU General Public License version 3 or later, see
http://gnu.org/licenses/gpl.html
SEE ALSO
sh(1) bash(1)