#!/bin/bash
WEB_SERVER=steve-parker.org
curl -# -f -u ${USERNAME}:${PASSWORD} http://${WEB_SERVER}/ | grep "SomeMessage"
RC=( "${PIPESTATUS[@]}" )
if [ "${RC[0]}" -eq "22" ]; then
  # curl returned 22, indicating some error above 400, 
  # such as: 404 Not Found, 401 Unauthorized, etc.
  echo "Invalid credentials"
  exit 1
fi

# PIPESTATUS has gone, but we can still inspect RC
if [ "${RC[1]}" -eq "0" ]; then
  echo "Grep succeeded"
  echo "Web server reported SomeMessage"
else
  echo "Web server didn't report SomeMessage"
fi