#!/bin/bash

current_uid=$(id -u)

if [ "$current_uid" -eq 0 ]; then
  echo "please run as a normal user"
  exit 1
fi

tab=$'\t'

kde_conf="${HOME}/.config/kwinrc"
if [ -e "$kde_conf" ]; then
  true
else
  echo "file $kde_conf not exist"
  exit 1
fi

confline_Xrander="Backend=XRender"
sed -in "/\[Compositing\]/,/^$/{/^[[:space:]]*Backend=/{d}}" ${kde_conf}
sed -in "/\[Compositing\]/a\\${confline_Xrander}" ${kde_conf}

echo "all changes have been made, please reboot to take effect"