GNU nano 4.8                                                    /etc/systemd/system/l4d2-server-a.service
[Unit]
Description=l4d2 Server A
After=network.target steam-update.service

[Service]
User=steam
WorkingDirectory=/home/steam/steam/l4d2
ExecStart=/home/steam/steam/l4d2/srcds_run -port 27001 -secure +exec server_a.cfg
Restart=on-failure

[Install]
WantedBy=multi-user.target