Running functions that were declared outside my shell script

Question

Currently my ZSH has some sourced functions, for instance:

% declare -f
     ... a lot of shell functions appears here.

I'm currently writing a shell script that will call a specific function from that list (prompt_dir from Powerlevel9k's theme for Oh-My-Zsh).

My script is:

#!/bin/zsh
echo_prompt_segment(){
    # bunch of source-code here
}

zsh_oddeven_dir(){
   prompt_dir echo
}

zsh_oddeven_dir

Problem is that my script cannot access these functions:

% ./oddeven-pwd.sh
zsh_oddeven_dir:1: command not found: prompt_dir

When I do declare -f from inside the script, there are only those two functions that's inside my script:

% ./oddeven-pwd.sh 
echo_prompt_segment () {

}
zsh_oddeven_dir () {
    declare -f
}

Can I access and run those functions that were declared above my script? If so, how?

Answer 1

Since by default scripts run in subshells, the facility you require is exported functions, available in bash, but not in zsh.

In bash the standard place to add user functions is in ~/.bashrc, but this is not executed unless bash is interactive (specifically, not in a subshell running a script), which exported functions overcome.

What does seem to work, as per this answer, is to put your function declarations in ~/.zshenv, which is executed by default on every launch, interactive or not.

You should also look at the previous (accepted) answer, which among other things explains the reason that zsh does not support exported functions.