find overridden features and fail the job

gistfile1.txt

#!/bin/bash
# Bring out the noise.
set -ux

# Look for modified features.
MODIFIED_FEATURES=`drush @drush.alias fl | grep -Eio "[a-z].*enabled.*7\..*overridden"`

if [ -z "$MODIFIED_FEATURES" ]
then
  # If they are not modified, you can do stuff here.
else
  # Print them out.
  echo "========================================================================="
  echo "================The following features have been modified...============="
  echo "========================================================================="
  echo $MODIFIED_FEATURES
  echo "========================================================================="
  # exit 1 makes the job fail so it sends a fail email.
  exit 1
fi