toggle_k380_function_keys.sh

#!/bin/sh

# wrapper script for toggling fn keys on k380 keyboard in Linux (Xubuntu 19.04)

# `toggle_k380_functions_keys.sh` is bound to <alt>-<esc> in "keyboard -> application shortcuts"
# and I ensured that `/usr/local/bin/k380_conf` is configured to run w/ sudo's NOPASSWD option

# useful links:
# * https://askubuntu.com/questions/699138/logitech-k380-bluetooth-keyboard-make-function-keys-default
# * https://github.com/jergusg/k380-function-keys-conf
# * http://www.trial-n-error.de/posts/2012/12/31/logitech-k810-keyboard-configurator
# * https://askubuntu.com/questions/821919/how-do-i-add-sudo-commands-to-a-keyboard-shortcut


ADDRESS="046D:B342"
LOCKFILE="${0%.*}.lock"
DEVICE=`ls /sys/class/hidraw/ -l | grep $ADDRESS | grep -o 'hidraw[0-9]*$'`


if [ -z "$DEVICE" ]; then 
  echo "K380 does not seem to be connected.  Try again later">&2;
  exit;
fi


if [ -f "$LOCKFILE" ]; then
  sudo k380_conf -d "/dev/$DEVICE" -f off;
  rm $LOCKFILE;
else
  sudo k380_conf -d "/dev/$DEVICE" -f on;
  touch $LOCKFILE;
fi