LPI (Linux Professional Institute)-LPI Level 1 Exam 102, Junior Level Linux Certification, Part 2 of 2 Set 1

set -o safe ✘ set -o noglob ✘ set -o noclobber ✘ set -o append ✔ set -o nooverwrite ✔

unset -v FOOBAR ✘ set -a FOOBAR="" ✘ env -u FOOBAR myscript ✘ env -i FOOBAR myscript ✔

the process ID of the echo command ✘ the process ID of the current shell ✘ the process ID of the last command executed ✘ the process ID of the last backgrounded command ✔

The batch command will run multiple times.The at command will only run once. ✘ The batch command will run when system load is low. The at command runs at a specifictime. ✘ The at command reads commands from standard input. The batch command requires a command line argument. ✘ The at command e-mails results to the user. The batch command logs results to syslog. ✔

* 3,4,5 1 * * chklog

✘

3 3,4,5 1 * * chklog

✘

3 15,16,17 * * * chklog

✘

0 15,16,17 1 * * chklog

✔

* 15,16,17 1 * * chklog

✔

cat UTC > /etc/timezone ✘ ln -s /usr/share/zoneinfo/UTC /etc/localtime ✘ date --timezone=UTC ✘ mv /usr/timezone/UTC /etc ✔

*

✘

-

✘ s ✘ x ✔

The encrypted passwords are still subject to brute force attacks. ✘ This is just for historical reasons. ✘ There is other information in the file that needs to be kept secret. ✘ The passwords can be decrypted by anyone with root access. ✔

Add the user name to /etc/nologin. ✘ Change the user's password. ✘ Change the user name in /etc/passwd. ✘ Use change to expire the user account. ✔ Place the command logout in the user's profile. ✔

Every user may have their owncrontab. Changing a crontab requires a reload/restart of the cron daemon. The cron daemon reloads crontab files automatically when necessary. hourly is the same as "0 * * * *". A cron daemon must run for each existing crontab.