Todo.txt: Action helper: Filter with `python3` as `python`

filter_with_python3_as_python

#!/usr/bin/env sh

# Mainly for use with <https://github.com/FND/todo.txt-cli/blob/1bdbdf41464826cc85e84ae8c3c17336e24a2922/futureTasks>

# Installation:
# 1. `cd "$TODO_ACTIONS_DIR"`
# 2. `mkdir -p helpers`
# 3. `mkdir -p filters`
# 4. `ln -s /path/to/filter_with_python3_as_python helpers/` (where `/path/to/filter_with_python3_as_python` is this file)
# 5. `ln -s /path/to/filter_cmd filters/` (where `/path/to/filter_cmd` is to be used as `TODOTXT_FINAL_FILTER`)
# 6. `ln -s helpers/filter_with_python3_as_python filter_cmd`

set -euf

if [ "$#" -ge 1 ]; then
	filter="$1"
	shift
else
	filter="$TODOTXT_DEFAULT_ACTION"
fi

export TODOTXT_FINAL_FILTER="$TODO_ACTIONS_DIR/filters/$filter | $TODOTXT_FINAL_FILTER"

if command -v python > /dev/null 2>&1 || ! which python3 > /dev/null 2>&1; then
	exec "$TODO_SH" ls "$@"
fi

exit_code=0

temp_python_path="$(mktemp -d)"
ln -s "$(which python3)" "$temp_python_path/python"
export PATH="$PATH:$temp_python_path"

"$TODO_SH" ls "$@" || exit_code="$?"

rm -r "$temp_python_path"

exit "$exit_code"