Awesome

shfmt

A shell formatter. Supports POSIX Shell, Bash, and mksh.

This project is a fork of mvdan. This fork contains the same formatting functionality as the original project, and in additional to that, several unique options (such as the option to disable line splitting) that weren't allowed into the original project.

Usage

Download it here.

To use it in an editor (like PhpStorm etc), make a cmd like this and then reference that (instead of the exe).

Description

shfmt formats shell programs. It can use tabs or any number of spaces to indent.

You can feed it standard input, any number of files or any number of directories to recurse into. When recursing, it will operate on .sh and .bash files and ignore files starting with a period. It will also operate on files with no extension and a shell shebang.

shfmt -l -w script.sh

Typically, CI builds should use the command below, to error if any shell scripts in a project don't adhere to the format:

shfmt -d .

Use -i N to indent with a number of spaces instead of tabs. There are other formatting options - see shfmt -h. For example, to get the formatting appropriate for Google's Style guide, use shfmt -i 2 -ci.

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.

An example of the options available:

[*.sh]
# like -i=4
indent_style = space
indent_size = 4

shell_variant      = posix # like -ln=posix
binary_next_line   = true  # like -bn
switch_case_indent = true  # like -ci
space_redirects    = true  # like -sr
keep_padding       = true  # like -kp
function_next_line = true  # like -fn
never_split        = true  # like -ns

# Ignore the entire "third_party" directory.
[third_party/**]
ignore = true

Caveats

When indexing Bash associative arrays, always use quotes. The static parser will otherwise have to assume that the index is an arithmetic expression.

$ echo '${array[spaced string]}' | shfmt
1:16: not a valid arithmetic operator: string
$ echo '${array[dash-string]}' | shfmt
${array[dash - string]}

$(( and (( ambiguity is not supported. Backtracking would complicate the parser and make streaming support via io.Reader impossible. The POSIX spec recommends to space the operands if $( ( is meant.

$ echo '$((foo); (bar))' | shfmt
1:1: reached ) without matching $(( with ))

Some builtins like export and let are parsed as keywords. This is to allow statically parsing them and building their syntax tree, as opposed to just keeping the arguments as a slice of arguments.