AltSH formatter (experimental)

The altshfmt is an experimental tool for formatting AltSH (alternative shell script) with extended syntax that cannot be formatted correctly by shfmt. This is implemented as a wrapper for shfmt.

Currently supported syntax: ShellSpec, shpec

Use it at your own risk

• It has not been enough tested. Please make sure to save and version control your files properly so that they can be restored even if they are corrupted.
• It depends on the behavior of shfmt, so it may not work depending on the combination of versions.
• Incompatible changes may be made.

Requirements

• shfmt v3.2.1
• Basic commands (awk, cat, cmp, cp, diff, grep, ls, mktemp, rm, sed, which)

How to use

Since altshfmt is implemented as compatible as possible with shfmt, You can use it instead of the shfmt command.

Linux or macOS

• Download altshfmt archive from here and extract it to a directory, or use git clone.
• Download shfmt binary from here and save it in the directory where altshfmt is located.

Windows

WSL (Windows 10, version 1803 and later) or busybox-w32 is required. To run it from Windows (instead of from WSL), run altshfmt.bat instead of altshfmt.

WSL

• Download altshfmt archive from here and extract it to a directory, or use git clone.
• Download shfmt binary from here and save it in the directory where altshfmt is located.
• The shfmt binary can be used for Windows or Linux.

busybox-w32

• Download altshfmt archive from here and extract it to a directory, or use git clone.
• Download shfmt binary from here and save it in the directory where altshfmt is located.
• Download busybox binary from here, rename it to bash.exe and save it in the directory where altshfmt is located.

Using with VSCode

Use the shell-format (github) extension.

• Install the shell-format extension and change shellformat.path in settings.json to the path to the altshfmt (or altshfmt.bat for windows).

About syntax detection

The syntax is automatically determined from the beginning and ending pairs of the block of DSL used in the shell script.

shell directive

If you have problems with the automatic detection, you can also use the shell directive. The shell directive is a comment that begins with "shell:".

Example

#!/bin/sh
# shell: sh altsh=shellspec

Describe
  ...
End

Usage: shell: [<shell>] [altsh=<syntax>]

• shell: sh, bash, mksh
  • Unspecified: same as auto
  • It is treated as the value of the -ln flag of the shfmt command
    • auto: do not specify the -ln flag
    • sh: implies -ln posix
    • bash: implies -ln bash
    • mksh: implies -ln mksh
    • Others: implies -ln bash
• syntax: shellspec, shpec
  • Unspecified: Treat it as a pure shell script
  • Others: Treat it as a pure shell script

Limitation

altshfmt is several times slower than shfmt.