set_screenres.sh

#!/bin/bash
# This script will set your Linux desktop to use a custom screen resolution.
# Set your resolution in the variables below, and then run the script each time your VM boots.
# Bam!  No more annoying issues with your VM screen being too big or too small!
#
# Author: CP Jamie, with some help from StackOverflow

width=1280
height=1024
refreshrate=60

res_name="${width}x${height}_${refreshrate}hz"
res_modeline=$(cvt $width $height ${refreshrate} | tail -1 | cut -d ' ' -f 3-)
monitor_name=$(xrandr --listactivemonitors | tail -1 | cut -d ' ' -f 6)

xrandr --newmode $res_name $res_modeline
xrandr --addmode $monitor_name $res_name
xrandr --output $monitor_name --mode $res_name