In this hands-on project, you schedule processes by using the at and crontab utilities....

In this hands-on project, you schedule processes by using the at and crontab utilities.

1. Switch to a command-line terminal (tty2) by pressing Ctrl+Alt+F2 and log in to the terminal using the user name of root and the password of secret.

2. Schedule processes to run one minute in the future by typing the command at now + 1 minute at a command prompt, and press Enter.

3. When the at> prompt appears, type the word date and press Enter.

4. When the second at> prompt appears, type the word who and press Enter.

5. When the third at> prompt appears, press the Ctrl+d key combination to finish the scheduling and observe the output. When will your job run? Where will the output of the date and who commands be sent?

6. In approximately one minute, you will receive mail from the at daemon. Check your mail by typing mail at the command line and pressing Enter. Look for the e-mail with the subject “Output from your job” and record the number: _______________.

7. At the & prompt, type the number that corresponds to the e-mail in the previous step, press Enter, and observe the output. When finished, type q at the & prompt, and press Enter to exit the mail program.

8. At the command prompt, type crontab -l and press Enter to list your cron table. Do you have one?

9. At the command prompt, type crontab -e and press Enter to edit a new cron table for the root user. When the vi editor appears, add the line: 30 20 * * 5 /bin/false

10. When you finish typing, save and quit the vi editor and observe the output on the terminal screen.

11. At the command prompt, type crontab -l and press Enter to list your cron table. When will the /bin/false command run?

12. At the command prompt, type cat /var/spool/cron/root and press Enter to list your cron table from the cron directory. Is it the same as the output from the previous command?

13. At the command prompt, type crontab -r and press Enter to remove your cron table.

14. Type exit and press Enter to log out of your shell.