How to fix numeric keypad on Linux not working with java applications

fix-numeric-keypad

# credit to Peter L on StackOverflow: 
# https://stackoverflow.com/questions/32753190/how-to-get-numeric-keypad-arrows-working-with-java-applications-on-linux/32753332#32753332

#!/bin/bash

SYMBOLS="/usr/share/X11/xkb/symbols"
KEYPAD="$SYMBOLS/keypad"

# create a backup in a temporary directory
TMP=$(mktemp -d)
cp "$KEYPAD" "$TMP/keypad"

# make a numbered backup in the original directory
sudo cp --backup=numbered "$TMP/keypad" "$SYMBOLS"

# fix the keypad file into the temporary directory
KEYS=("Up" "Down" "Left" "Right" "Home" "End" "Prior" "Next")
REGEX="s/KP_\("${KEYS[0]}$(printf "\|%s" "${KEYS[@]:1}")"\)/\1/g"
sed -e "$REGEX" "$KEYPAD" > "$TMP/keypad"

# overwrite the original keypad file
sudo cp "$TMP/keypad" "$KEYPAD"

# delete the temporary directory
rm -rf "$TMP"

# update the xkb symbols
sudo dpkg-reconfigure xkb-data