[pavon]

Or just a multiline string:

  #!/bin/bash
  USAGE="my-script — does one thing well
    
    Usage:
      my-script <input> <output>
    
    Options:
      <input>   Input file to read.
      <output>  Output file to write. Use '-' for stdout.
      -h        Show this message.
  "

  help() {
    echo "$USAGE"
  }

This is my standard approach which is cleaner for putting the documentation at the very top of the file like the linked article.

[sillysaurusx]

Thank you! I had no idea that multiline strings were valid bash.

[rkangel]

It's the same logic that allows you to type:

git commit -m "First line of commit

Second line of commit"

That's a multi-line string in bash.

[GordonS]

Woah, I had no idea multiline strings were even a thing in Bash, I've been using heredocs for help messages since forever!

Do you know if these are portable?

[pavon]

As far as I know. The POSIX spec[1] simply declares that in single quotes all characters will be preserved exactly, except for single quotes, which aren't allowed. Likewise, for double quotes, except that it also performs expansions ($) and allows escaping (\).

[1]https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V...

[Anthony-G]

That's exactly what I do. For others who were not aware that multi-line strings can be used, this is POSIX-compatible (most of my shell scripts are executed by `dash`).

[tuatoru]

This is one (useful!) interpretation of "code should be self-documenting". Just put the documentation into strings.