How to tell if the same cronjob ran twice

Introduction

This article provides the steps to determine if the same cron job was run twice.

Procedure

1. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.
2. List the user's cron jobs.

   crontab -l -u $username

   Please note that "$username" must be replaced with the cron owner's username.
3. Copy the command run in the cron job.

   0 12 * * * /usr/local/bin/php -m > /file/php-modules

4. Search the cron log for the user and the command.

   grep "/usr/local/bin/php -m > /file/php-modules" /var/log/cron|grep cptest

   Please note that "/usr/local/bin/php -m > /file/php-modules" and "cptest" must be replaced with the command found in the user's crontab and the user's username.
5. Look for entries with the same timestamp.

   APR 01 04:30:01 srv002 CROND[1145]: (cptest) CMD (/usr/local/bin/php -m > /file/php-modules)
   APR 01 04:30:01 srv002 CROND[1278]: (cptest) CMD (/usr/local/bin/php -m > /file/php-modules)

6. Compare the PIDs. If the PIDs are different, the cron ran twice.
   Please note that the PID is the number in brackets after CROND.