The correct crontab entry to execute the script chklog three times per month between 3 p.m. and 5 p.m.: A. * 3,4,5 1 * * chklog B. 3 3,4,5 1 * * chklog C. 3 15,16,17 * * * chklog…

What is the main difference between the batch and at commands? A. The batch command will run multiple times.The at command will only run once. B. The batch command will run when system load is low. The at command runs…

In the following command and its output, echo $$ 12942 What is 12942? A. the process ID of the echo command B. the process ID of the current shell C. the process ID of the last command executed D. the…

How is the file format of /etc/crontab different from a normal crontab file? (Select TWO correct answers) A. The /etc/crontab file can specify a year field. B. A normal crontab file must be installed with the crontab command. C. A…

To test a shell script called myscript, the environment variable FOOBAR must be removed temporarily. How can this be done? A. unset -v FOOBAR B. set -a FOOBAR="" C. env -u FOOBAR myscript D. env -i FOOBAR myscript

Which bash option will prevent you from overwriting a file with a ">"? A. set -o safe B. set -o noglob C. set -o noclobber D. set -o append E. set -o nooverwrite