settitle

#!/usr/bin/env bash
# settitle -- update the terminal window titlebar or window name
# # TODO: DECSWT (supported by Windows Terminal 1.21)

usage() {
	echo "Usage: ${0##*/} [-arsw] <title>"
	echo ""
	echo "Update the terminal's window titlebar."
	echo ""
	echo "Options:"
	echo "  -a            use nonstandard BEL terminator instead of ST"
	echo "  -r            ask terminal to restore saved title"
	echo "  -s            ask terminal to save current title"
	echo "  -w            set tmux/screen \"window name\""
}

do_bel=0
do_save=0
do_restore=0
do_wname=0

while getopts "arsw" OPT; do
	case $OPT in
	a) do_bel=1;;
	r) do_restore=1;;
	s) do_save=1;;
	w) do_wname=1;;
	*) usage; exit 2;;
	esac
done; shift $((OPTIND-1))

title=$*

if (( do_wname )); then
	# Set tmux/screen window title
	if (( do_save || do_restore )); then
		echo "${0##*/}: save/restore ineffective for window name" >&2
		exit 1
	fi
	if (( do_bel )); then
		echo "${0##*/}: BEL terminator not used with this mode" >&2
		exit 1
	fi
	if [[ $TERM- == @(screen|tmux)-* ]]; then
		printf '\ek%s\e\\' "$title"
	fi
elif (( do_restore )); then
	# Restore (pop) window title if supported
	if [[ $title ]]; then
		echo "${0##*/}: cannot both restore and set new title" >&2
		exit 1
	fi
	if (( do_bel )); then
		echo "${0##*/}: BEL terminator not used with this mode" >&2
		exit 1
	fi
	printf '\e[23;2t'
else
	# Set regular Xterm window titlebar
	if (( do_save )); then
		# Save (push) window title if supported
		printf '\e[22;2t'
	fi
	# XXX: Should just use BEL everywhere for better compatibility?
	if (( do_bel )); then
		printf '\e]0;%s\a' "$title"
	else
		printf '\e]0;%s\e\\' "$title"
	fi
fi