mpv-active-sockets

#!/usr/bin/env bash
# Removes any inactive mpv sockets, lists active mpv sockets
# Exits unsuccessfully if no sockets are active

declare default_tmp_dir default_socket_dir
default_tmp_dir="${TMPDIR:-/tmp}"
default_socket_dir="${default_tmp_dir}/mpvsockets"

readonly SOCKET_DIR="${MPV_SOCKET_DIR:-${default_socket_dir}}"

# remove any mpv sockets which fail to respond to a basic command
is_active_socket() {
	# send a command to determine if the socket
	# is still active.
	# If its dead, removes the socket and returns 1
	if socat - "$1" <<<'{ "command": ["get_property", "path"] }' >/dev/null 2>&1; then
		return 0
	else
		rm "$1" >&2
		return 1
	fi
}

# find all active sockets, remove any that aren't active
declare -a active_sockets
active_sockets=()
while read -r -d $'\0' socket; do
	if is_active_socket "${socket}"; then
		active_sockets+=("${socket}")
	fi
done < <(find "${SOCKET_DIR}" -type s -print0)

((${#active_sockets[@]} == 0)) && exit 1
{
	for socket in "${active_sockets[@]}"; do
		echo "${socket}"
	done
} | sort -n