zsh: use completions for command X when I type command Y

Question

In zsh, I have a function called g which acts like this:

• with no arguments, call git status
• with one or more arguments, delegate to git with all given arguments - i.e. call git $@

I would like the tab completions for g to be exactly the same as for git. I can achieve this with alias g=git, but that doesn't allow me to call status by default (the first point above).

How can I delegate to the completion for git?

In bash, I simply did complete -F _git g which re-uses git's completion function. With zsh, git's completion looks much more complex, and I wan't able to find a similar solution.

I'd guess there's some function in zsh to say "pretend I typed command [x], what would you complete it to?". If I knew what that was, it should be simple enough to use a function to delegate to it. But I've found no such function in the manuals.

Agrarian

Thank you for the tip on how to make it work in bash! – Jacey

If you can change your function to conditionally print the commands it would execute instead of actually executing them, see this answer by yut23: https://mcmap.net/q/583453/-complete-a-command-with-arguments-like-another-command-with-other-arguments – Meaganmeager

Answer 1

The documentation for compdef says this:

The function compdef can be used to associate existing completion functions with new commands. For example,

compdef _pids foo

But adapting it (_git is the usual completion function for git) did not produce a working result for me (even after _git had been autoloaded):

compdef _git g

I was able to get it to work via _dispatch though:

compdef '_dispatch git git' g

Menhir

That's weird. I have the same thing happening, but other completion functions work just fine with the first command. – Heterodoxy

excellent, thank you very much! As for why the first doesn't work, Perhaps the completion for _git is sufficiently custom that just redirecting it isn't enough to get it to respond with anything useful? (i.e maybe it checks that the command starts with "git") – Agrarian

Any idea how compdef '_dispatch git git' g can be adjusted to make g auto-complete like git-status, rather than just git? – Whydah

This works for me when I run it directly in a zsh shell, but for some reason it doesn't work when I put it my .zshrc. – Disjoined

If you want to have a subcommand like git status, then apparently (by trial and error) I came up with compdef '_dispatch _git-status git' gst – Cooker

@DarioSeidl If you put it into your .zshrc, make sure that it is after your call autoload -Uz compinit && compinit – Cooker

Answer 2

This same function had stopped working for me after a change-around of configs.

# in ~/.zsh/functions/g.zsh

# # No arguments: `git status`
# # With arguments: acts like `git`
g() {
  if [[ $# > 0 ]]; then
    git "$@"
  else
    git status
  fi
}

It's actually important to place just the function in ~/.zsh/functions/g.zsh and create a compdef in ~/.zsh/completions/_g:

#compdef g
compdef g=git

Then, in .zshrc:

fpath=($HOME/.zsh/completions $fpath)

# load custom executable functions
for function in ~/.zsh/functions/*.zsh; do
  source $function
done

# completion
autoload -U compinit
compinit

Not sure if the order is important. I think when the compdef is in a separate folder, it works with any order.

Got the g function from here:

https://github.com/thoughtbot/dotfiles/blob/master/zsh/functions/g

https://github.com/thoughtbot/dotfiles/blob/master/zsh/completion/_g

Thanks Thoughtbot!

Polite