1shfmt(1) General Commands Manual shfmt(1)
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6 shfmt - Format shell programs
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9 shfmt [flags] [path...]
10
12 shfmt formats shell programs. If the only argument is a dash (-) or no
13 arguments are given, standard input will be used. If a given path is a
14 directory, all shell scripts found under that directory will be used.
15 If any EditorConfig files are found, they will be used to apply format‐
17 ting options. If any parser or printer flags are given to the tool, no
18 EditorConfig files will be used. A default like -i=0 can be used for
19 this purpose.
20 shfmt's default shell formatting was chosen to be consistent, common,
22 and predictable. Some aspects of the format can be configured via
23 printer flags.
24
26 Generic flags
27 -version
28 Show version and exit.
29 -l
31 List files whose formatting differs from shfmt's.
32 -w
34 Write result to file instead of stdout.
35 -d
37 Error with a diff when the formatting differs.
38 The diff uses color when the output is a terminal. To never use
40 color, set a non-empty NO_COLOR or TERM=dumb. To always use color,
41 set a non-empty FORCE_COLOR.
42 -s
44 Simplify the code.
45 -mn
47 Minify the code to reduce its size (implies -s).
48 Parser flags
50 -ln <str>
51 Language variant to parse (bash/posix/mksh/bats, default bash).
52 -p
54 Shorthand for -ln=posix.
55 -filename str
57 Provide a name for the standard input file.
58 Printer flags
60 -i <uint>
61 Indent: 0 for tabs (default), >0 for number of spaces.
62 -bn
64 Binary ops like && and | may start a line.
65 -ci
67 Switch cases will be indented.
68 -sr
70 Redirect operators will be followed by a space.
71 -kp
73 Keep column alignment paddings.
74 -fn
76 Function opening braces are placed on a separate line.
77 Utility flags
79 -f
80 Recursively find all shell files and print the paths.
81 -tojson
83 Print syntax tree to stdout as a typed JSON.
84
86 Format all the scripts under the current directory, printing which are
87 modified:
88 shfmt -l -w .
90 For CI, one can use a variant where formatting changes are just shown
92 as diffs:
93 shfmt -d .
95 The following formatting flags closely resemble Google's shell style
97 defined in <https://google.github.io/styleguide/shell.xml>:
98 shfmt -i 2 -ci -bn
100 Below is a sample EditorConfig file as defined by <https://editorcon‐
102 fig.org/>, showing how to set any option:
103 [*.sh]
105 # like -i=4
106 indent_style = space
107 indent_size = 4
108 shell_variant = posix # like -ln=posix
110 binary_next_line = true # like -bn
111 switch_case_indent = true # like -ci
112 space_redirects = true # like -sr
113 keep_padding = true # like -kp
114 function_next_line = true # like -fn
115 # Ignore the entire "third_party" directory.
117 [third_party/**]
118 ignore = true
119 shfmt can also replace bash -n to check shell scripts for syntax er‐
121 rors. It is more exhaustive, as it parses all syntax statically and re‐
122 quires valid UTF-8:
123 $ echo '${foo:1 2}' | bash -n
125 $ echo '${foo:1 2}' | shfmt >/dev/null
126 1:9: not a valid arithmetic operator: 2
127 $ echo 'foo=(1 2)' | bash --posix -n
128 $ echo 'foo=(1 2)' | shfmt -p >/dev/null
129 1:5: arrays are a bash feature
130
132 Maintained by Daniel Martí <mvdan@mvdan.cc>, who is assisted by other
133 open source contributors. For more information and development, see
134 <https://github.com/mvdan/sh>.
135 2022-02-23 shfmt(1)