Bash Script for running multisite drush in parallel

drupal_parallel_drush.sh

#!/bin/bash

DRUPALPATH=$1
shift

if [ "$DRUPALPATH" == "" ]
then
  echo "Usage: $0 drupal-path drush-command with-args?"
  exit 1
fi

DRUSHCOMMAND=$@

if [ "$DRUSHCOMMAND" == "" ]
then
    echo "Usage: $0 drush-command with-args?"
    exit 1
fi

function parallel_drush_cmd() {
  SITE=$(basename $1)
  OUTPUT=$(sudo drush -r $DRUPALPATH -l $SITE $DRUSHCOMMAND 2>&1)
  echo "$SITE - $DRUSHCOMMAND"
  echo "$OUTPUT"
  echo "----"
  return 0
}
export DRUPALPATH
export DRUSHCOMMAND
export -f parallel_drush_cmd

SITES=$(find $DRUPALPATH/sites/ -mindepth 1 -maxdepth 1 -type d -not -name "skel" -not -name "all" -not -name "default" -print)
echo "$SITES" | xargs -I{} -P 4 bash -c 'parallel_drush_cmd {}'