Write a shell function from the current shell script to antoher shell script

Question

I have a zsh shell script that looks as following:

# ! /usr/bin/env zsh
my_function () {
    echo "my function is running"
    python3 my_python_script.py
}

I would like to call this script and copy the function my_function to <file_location>/test.sh .

My current attempt looks as following:

# ! /usr/bin/env bash
BASEDIR=$(dirname "$0")

cat <<EOF > $BASEDIR/test.sh
my_function () {
    echo "my function is running"
    output_string=\$(python3 my_python_script.py);
}
EOF

Is it possible copy this function, ideally without turning the entire function into a string first?

EDIT: Added missing dollarsign with escape that caused python script to be called intstead of copied as a string

Answer 1

While I wouldn't recommend using this method for anything other than testing purposes, you can achieve this goal via the type command.

# cat test.sh
testfunc() {
        echo "Running testfunc"
}

# Append the function definition to tmp.sh, using tail to skip the 'testfunc is a function' line
type testfunc | tail -n +2 >> tmp.sh
# ./test.sh
# cat tmp.sh
testfunc ()
{
    echo "Running testfunc"
}