Linux Periodic Processes Creating User cron Jobs 1. Login to your vApp through your student account and open up a terminal 2. Create and edit a file called cronjob in your student accounts home directory. Use vi to edit the file which should contain the following lines: SHELL=/bin/bash MAILTO=student 00 12 * * * /sbin/ifconfig Be sure to type these lines exactly; a typo will cause problems. Cron uses the MAILTO environment variable to determine to whom to email the output of cron jobs 3. Type crontab cronjob to install the cronjob file as a cron job. Note that this command replaces any existing user crontabs that may exist. If youve already defined user crontabs for your account, you should edit your existing cronjob file to add the line calling ifconfig rather than create a new file, or type crontab e to edit the copy of the file in the crontab storage directory 4. Wait for noon (00 12 in the cron time format). When this time rolls around, you should have a new email waiting for you with the contents of the ifconfig output. 5. Rather than waiting for noon, you can substitute a time thats a couple of minutes in the future. Remember that cron specifies minutes first, followed by the hour in a 24-hour format. For instance, if you create the file at 3:52pm, you might enter 54 15 as the first two numbers on the file line of the file; this will cause the cron job to execute at 15:54 on a 24 hour clock or at 3:54pm.