Center and optionally resize a window (X11)

cw.sh

#!/usr/bin/env bash

# uses wmctrl and xdotool
#
# improved upon the solutions listed in
#   https://askubuntu.com/questions/104155/center-a-window-via-command-line

if [[ "$1" == "-h" || "$1" == "--help" ]]; then
  echo "Usage: $0 \"window name\" [ WxH ]"
  exit 0
fi

# use active window by default
if [[ $# -eq 0 || "$1" == "" ]]; then
  wn=$(xdotool getactivewindow getwindowname)
else
  wn="$1"
fi

# get desktop size
IFS='x' read sw sh < <(xdpyinfo | grep dimensions | grep -o '[0-9x]*' | head -n1)

# get window size
read wx wy ww wh < <(wmctrl -lG | grep "$wn" | sed 's/^[^ ]* *[^ ]* //;s/[^0-9 ].*//;')

# optional: use new window size
if [[ $# -eq 2 ]]; then
  # IFS='x' read -e -i "$2" ww wh
  IFS='x' read ww wh < <(echo "$2")
fi

nx=$(( (sw-ww) / 2 ))
ny=$(( (sh-wh) / 2 ))

# xdotool getactivewindow windowmove "$nx" "$ny"
wmctrl -r "$wn" -e 0,$nx,$ny,$ww,$wh