This little script will help you to understand how to use xrandr to enable, disable and configure your second Display via bash:

#!/bin/bash

FIRST="HDMI-0"
SECOND="DVI-0"

BASECMD="xrandr --auto --output $SECOND"

MODE="--mode 1920x1080"
DIRECTION="--right-of $FIRST"
ROTATE="--rotate left"
OFF="--off"

function off() {
  $BASECMD $OFF
}

function on() {
  $BASECMD $MODE $DIRECTION $ROTATE
}

function usage() {
  echo "usage: $(basename $0) on|off"
}

case "$1" in
  on)   on 
  ;;
  off)  off 
  ;;
  *)    usage
  ;;
esac

Enjoy!