Get Function Into PS1 (Zsh)?

Question

This works in Bash (parse_git_branch is a defined function)

export PS1="\$(parse_git_branch)"

but I cannot figure out the equivalent in zsh.

Note: If I do

PROMPT="$(parse_git_branch)"

it seems to work, but in fact it's running the command when I set the prompt, which is not the point.

Answer 1

you have to

setopt PROMPT_SUBST

in your .zshrc, man zshall explains it in the PROMPT EXPANSION section:

If the PROMPT_SUBST option is set, the prompt string is first subjected to parameter expansion, command substitution and arithmetic expansion.

Answer 2

As akira says, you have to use prompt subst. This is my early code (still working on it):

setopt PROMPT_SUBST
PROMPT='$(parse_git_branch)'

or better

setopt PROMPT_SUBST
PROMPT='[$PR_MAGENTA%n$PR_NO_COLOR@$PR_GREEN%U%m%u$PR_NO_COLOR:$PR_RED%2c$PR_NO_COLOR]$(parse_git_branch) %(!.#.$)'

Answer 3

Actually your problem was not just setting PROMPT_SUBST: you use double quotes in your script forcing the evaluation of the function when you set the PROMPT variables. You only want evaluation when the prompt is computed that is you must use single quotes.