#!/bin/bash
set -euo pipefail

# This is a helper wrapper script for greetd.
#
# It will run the session / application using the appropriate shell configured for
# this user. That way, we can make sure all of the environment variables are set
# before the WM/DE session is started.
#
# This is very important, as without it, variables for things like qt theme
# will not be set, and applications executed by the WM/DE will not be themed properly.

script_name="$0"
shell="$(getent passwd "$USER" | awk -F: '{print $NF}')"
command=("$@")

# This syntax might be a bit confusing at first. It works as follows:
# 1. Replace this wrapper process with the user's login shell (through exec)
# 2. The shell is told to run 'exec $@' replacing itself with another process
# 3. The $@ in the exec above referrs to the arguments passed the shell (after -c '...')
# 4. "$script_name" is passed to the shell as $0 (process name), not included in $@
# 5. The ${command[@]} matches the $@ which this script was called with
# -> The command passed into this script as args is ran within the user's shell
exec "$shell" -c 'exec "$@"' "$script_name" "${command[@]}"