dots/bin/tmx

#!/bin/sh

# ------------------------------------------------------------------------------
#
# Modified TMUX start script from:
#	 http://forums.gentoo.org/viewtopic-t-836006-start-0.html
#
# Store it to `~/bin/tmx` and issue `chmod +x`.
#
# ------------------------------------------------------------------------------

function check_session() {
	local postfix="$1"
	shift

	"${tmux[@]}" -L "session-$postfix" list-sessions -F "#S" 2>/dev/null | grep -q "$base_session-$postfix"
}

tmux=( "tmux" )
base_session="$USER"

if [[ "$XDG_SESSION_ID" ]] && check_session "$XDG_SESSION_ID"; then
	tmux+=( "-L" "session-$XDG_SESSION_ID" )
	base_session+="-$XDG_SESSION_ID"
fi

# ------------------------------------------------------------------------------

new_session="${base_session}-$$"

if (( $("${tmux[@]}" ls | wc -l) == 0 )); then
	exec "${tmux[@]}" new -s "$new_session"
else
	# Count tmux sessions (1 master + N slaves).
	# If there are no slave sessions, do not create new windows.
	if (( $("${tmux[@]}" ls | wc -l) > 1 )); then
		NEW_WINDOW_COMMAND=("new-window" "$*" ";")
	fi

	# Create a new session (without attaching it) and link to base session to share windows
	# Attach to the new session & kill it once orphaned
	exec "${tmux[@]}" new-session -d -t "$base_session" -s "$new_session" \; \
	                  attach-session -t "$new_session" \; \
	                  "${NEW_WINDOW_COMMAND[@]}" \
	                  set-option destroy-unattached
fi