#!/bin/sh
  
# This script is a watchdog checking whether
# the server is online.
# It tries to restart the server, and if it is
# down it sends an email alert to the admin.

# admin's email
EMAIL=webmaster@example.com
  
# the path to the PID file
PIDFILE=/home/httpd/httpd_perl/logs/httpd.pid
  
# the path to the httpd binary, including any options if necessary
HTTPD=/home/httpd/httpd_perl/bin/httpd_perl
      
# check for pidfile
if [ -f $PIDFILE ] ; then
    PID=`cat $PIDFILE`
    
    if kill -0 $PID; then
        STATUS="httpd (pid $PID) running"
        RUNNING=1
    else
        STATUS="httpd (pid $PID?) not running"
        RUNNING=0
    fi
else
    STATUS="httpd (no pid file) not running"
    RUNNING=0
fi
    
if [ $RUNNING -eq 0 ]; then
    echo "$0 $ARG: httpd not running, trying to start"
    if $HTTPD ; then
        echo "$0 $ARG: httpd started"
        mail $EMAIL -s "$0 $ARG: httpd started" \
             < /dev/null > /dev/null 2>&1
    else
        echo "$0 $ARG: httpd could not be started"
        mail $EMAIL -s "$0 $ARG: httpd could not be started" \
             < /dev/null > /dev/null 2>&1
    fi
fi