shfmt(1)
shfmt - Format shell programs
shfmt [flags] [path...]
shfmt formats shell programs. If the only argument is a dash (-) or no arguments are given, standard input will be used. If a given path is a directory, all shell scripts found under that directory will be used.
If any EditorConfig files are found, they will be used to apply formatting options. If any parser or printer flags are given to the tool, no EditorConfig files will be used. A default like -i=0 can be used for this purpose.
shfmt's default shell formatting was chosen to be consistent, common, and predictable. Some aspects of the format can be configured via printer flags.
-version Show version and exit.
-l, --list List files whose formatting differs from shfmt's.
-w, --write Write result to file instead of stdout.
-d, --diff Error with a diff when the formatting differs.
The diff uses color when the output is a terminal.
To never use color, set a non-empty *NO_COLOR* or *TERM=dumb*.
To always use color, set a non-empty *FORCE_COLOR*.-s, --simplify Simplify the code.
-mn, --minify Minify the code to reduce its size (implies -s).
-ln, --language-dialect Language dialect (bash/posix/mksh/bats, default auto).
When set to *auto*, the language is detected from the input filename,
as long as it has a shell extension like *foo.mksh*. Otherwise, if the input
begins with a shell shebang like *#!/bin/sh*, that's used instead.
If neither come up with a result, *bash* is used as a fallback.
The filename extension *.sh* is a special case: it implies *posix*,
but may be overriden by a valid shell shebang.-p, --posix Shorthand for -ln=posix.
-filename str Provide a name for the standard input file.
-i, --indent Indent: 0 for tabs (default), >0 for number of spaces.
-bn, --binary-next-line Binary ops like && and | may start a line.
-ci, --switch-case-indent Switch cases will be indented.
-sr, --space-redirects Redirect operators will be followed by a space.
-kp, --keep-padding Keep column alignment paddings.
-fn, --func-next-line Function opening braces are placed on a separate line.
-f, --find Recursively find all shell files and print the paths.
-tojson Print syntax tree to stdout as a typed JSON.
Format all the scripts under the current directory, printing which are modified:
shfmt -l -w .For CI, one can use a variant where formatting changes are just shown as diffs:
shfmt -d .The following formatting flags closely resemble Google's shell style defined in https://google.github.io/styleguide/shell.xml:
shfmt -i 2 -ci -bnBelow is a sample EditorConfig file as defined by https://editorconfig.org/, showing how to set any option:
[*.sh]
# like -i=4
indent_style = space
indent_size = 4
shell_variant = posix # --language-variant
binary_next_line = true
switch_case_indent = true # --case-indent
space_redirects = true
keep_padding = true
function_next_line = true # --func-next-line
# Ignore the entire "third_party" directory.
[third_party/**]
ignore = trueshfmt can also replace bash -n to check shell scripts for syntax errors. It is more exhaustive, as it parses all syntax statically and requires valid UTF-8:
$ echo '${foo:1 2}' | bash -n
$ echo '${foo:1 2}' | shfmt >/dev/null
1:9: not a valid arithmetic operator: 2
$ echo 'foo=(1 2)' | bash --posix -n
$ echo 'foo=(1 2)' | shfmt -p >/dev/null
1:5: arrays are a bash featureMaintained by Daniel Martí mvdan@mvdan.cc, who is assisted by other open source contributors. For more information and development, see https://github.com/mvdan/sh.