Why is “./script.sh -h” better than “less script.sh”?
Help Message for Shell Scripts
31–40 of 129 posts
Re: Help Message for Shell Scripts
#32Handling of arguments is one of the reasons I reach for Python or Powershell instead of a bash script when writing my own stuff. https://docs.python.org/3/library/argparse.html is great. Powershell has the Param keyword that functions like argparse in Python https://docs.microsoft.com/en-us/powershell/module/microsoft...
> https://docs.python.org/3/library/argparse.html is great Argparse is okay (and being in stdlib makes it always-available), but it's no click. https://click.palletsprojects.com/en/7.x/
This is why I love the HN community, learning something new every day. (Happy 10,000) I use argparse because it is stdlib, but will checkout click!
Re: Help Message for Shell Scripts
#33You can also use a "here document" help() { cat Options: Input file to read. Output file to write. Use '-' for stdout. -h Show this message. EOH } If the indentation bugs you, you can use a simpler sed trick to remove leading space so that you can indent it as desired: help() { sed -e 's/ //' Options: Input file to read. Output file to write. Use '-' for stdout. -h Show this message. EOH }
But now the sed line bugs me ;)
Re: Help Message for Shell Scripts
#34Pretty sure this won't work if the script is called via $PATH
x=$(command -v $0 2>/dev/null)
sed -rn 's/^### ?//;T;p' $x
exec sed -n '/^###/p' $x
Re: Help Message for Shell Scripts
#35I also posted to the github gist, this the sed command here is not cross-plataform friendly. You can accomplish the same thing with an awk command though: awk '/^###/' "$0"
sed -n '/^###/p' is cross-platform friendly.
Re: Help Message for Shell Scripts
#36You can also use a "here document" help() { cat Options: Input file to read. Output file to write. Use '-' for stdout. -h Show this message. EOH } If the indentation bugs you, you can use a simpler sed trick to remove leading space so that you can indent it as desired: help() { sed -e 's/ //' Options: Input file to read. Output file to write. Use '-' for stdout. -h Show this message. EOH }
You can also use add a hyphen ( https://linuxhint.com/bash-heredoc-tutorial/
Seriously, bash has too many obscure features.
Re: Help Message for Shell Scripts
#37I used this strategy in "fx" which is a development helper frontend for fuchsia builds and tools. I used four # for the "short description" and three for the long description. The reason I used the strategy there is that lot of our scripts delegate arguments to native commands, and so adding help purely to --help wasn't really a good ROI. Implementation: https://fuchsia.googlesource.com/fuchsia/+/refs/heads/master...
Re: Help Message for Shell Scripts
#38This is not elegant, this is an ugly hack at best.
Re: Help Message for Shell Scripts
#39I like the idea of combining the header with the help documentation to reduce the number of areas to maintain in smaller scripts. For larger scripts though, I think I'd still prefer to have a separate function, so that the help documentation doesn't overwhelm the initial viewing of the actual code. I also like to feed a heredoc directly into man, which allows you to achieve nicer formatting for the help documentation…
Note that this doesn't work on macOS, where the builtin `man` command doesn't support the `-l` option.
Re: Help Message for Shell Scripts
#40Handling of arguments is one of the reasons I reach for Python or Powershell instead of a bash script when writing my own stuff. https://docs.python.org/3/library/argparse.html is great. Powershell has the Param keyword that functions like argparse in Python https://docs.microsoft.com/en-us/powershell/module/microsoft...
I also really like the "flag" package for Go, it generates the help text for you and easily lets you set defaults as well as helps you type-check inputs.