setmonitorposition

#!/bin/bash
# DESCRIPTION: Set position of a monitor relative to others.
# DEPENDENCIES: dmenu xrandr

[ -n "$1" ] && subjectmon="$1"
MONITORS=( $(xrandr -q | awk '$2 == "connected" {print $1}') )

in_MONITORS ()
{
	# Empty input: trivially not in monitors.
	[ -z "$1" ] && return 1
	local m
	for m in "${MONITORS[@]}"; do
		if [ "$1" = "$m" ]; then
			# Found.
			return 0
		fi
	done
	return 1
}

if ! in_MONITORS "$subjectmon"; then
	mon="$(for m in "${MONITORS[@]}"; do echo "$m"; done |
		dmenu -l 20 -p 'Which monitor to change?')" || exit 1
else
	mon="$subjectmon"
fi
[ -z "$mon" ] && exit 1

relativetomon="$(for m in "${MONITORS[@]}"; do [ "$m" != "$mon" ] && echo "$m"; done |
	dmenu -l 20 -p "$mon: Which monitor to position relative to?")" || exit 1
[ -z "$relativetomon" ] && exit 1

position="$(cat <<'EOF' | dmenu -l 20 -p "$mon->$relativetomon: Which position?"
left-of
right-of
above
below
same-as
EOF
)"

xrandr --output "$mon" --auto --"$position" "$relativetomon" && notify-send -t 5000 monitor_position "Set '$mon' ${position/-/ } '$relativetomon'"