Commands present in the shell are not being recognized when put up in a cron job

Question

I have a script to monitor my server, it sends a mail alert if the server are not ping-able. But when I set the script as a cron job , it throws error as ping command not recognized , mailx command not recognized ; while the same is working when executed manually.

Below is the code of the script

#!/bin/sh

cd `dirname $0`

serverIPs="192.0.0.40 192.0.0.140"

count=4

##checking the status by pinging the individual ips in serverIps variable

for host in $serverIPs
do
    recCount=$(ping -c $count $host | grep 'received' | awk -F',' '{ print $2 }' | awk '{ print $1 }')
    if [ $recCount -eq 0 ]; then
        # 100% failed 
            echo "Host : $host is down (ping failed) at $(date)" |mailx -s "Server is not responding completely " jagdeep.gupta@gmail.com
    elif [ $recCount -lt 4 ]
    then
        echo "Host : $host is not responding well there is loss of packets , please check " |mailx -s "Server is not responding partially " jagdeep.gupta@gmail.com
    fi
done

Answer 1

Your Cron Daemon likely flushes the environment, along with the $PATH variable. Try to add

export PATH=/bin:/usr/bin

at the beginning of your script. (This should suffice. If it does not, check the output of echo $PATH and use that as the value.)