Improvement of the regex performance for lid monitoring

This version of the regex avoids reading entire lines from the libinput
output, and concentrates on the event field.

contrib/etc/xdg/autostart/autorandr-lid-listener.desktop

@@ -2,5 +2,5 @@
 Name=Autorandr Lid Listener
 Comment=Trigger autorandr whenever the lid state changes
 Type=Application
-Exec=bash -c "stdbuf -oL libinput debug-events | grep --line-buffered SWITCH_TOGGLE | while read line; do autorandr --change --default default; done"
+Exec=bash -c "stdbuf -oL libinput debug-events | egrep --line-buffered '^ event[0-9]+\s+SWITCH_TOGGLE\s' | while read line; do autorandr --change --default default; done"
 X-GNOME-Autostart-Phase=Initialization

contrib/listen_lid.sh

@@ -3,6 +3,8 @@
 # /!\ You must be part of the input group
 # sudo gpasswd -a $USER input
 
-stdbuf -oL libinput debug-events | grep --line-buffered SWITCH_TOGGLE | while read line; do
+stdbuf -oL libinput debug-events | \
+    egrep --line-buffered '^ event[0-9]+\s+SWITCH_TOGGLE\s' | \
+    while read line; do
     autorandr --change --default default
 done

contrib/systemd/autorandr-lid-listener.service

@@ -3,7 +3,7 @@ Description=Runs autorandr whenever the lid state changes
 
 [Service]
 Type=simple
-ExecStart=bash -c "stdbuf -oL libinput debug-events | grep --line-buffered SWITCH_TOGGLE | while read line; do autorandr --batch --change --default default; done"
+ExecStart=bash -c "stdbuf -oL libinput debug-events | egrep --line-buffered '^ event[0-9]+\s+SWITCH_TOGGLE\s' | while read line; do autorandr --batch --change --default default; done"
 Restart=always
 RestartSec=30
 SyslogIdentifier=autorandr