LPI 702-100 Exam With Confidence Using Practice Dumps

The setenv command is used to set an environment variable in the csh or tcsh shell. The syntax is setenv VAR VALUE, where VAR is the name of the variable and VALUE is the value to assign to it. The TZ variable is used to specify the timezone for the shell and its subprocesses. To set the timezone to GMT (Greenwich Mean Time), the command is setenv TZ GMT. This will affect the output of commands like date and ls that display time information. The other options are either invalid syntax or belong to other shells, such as bash or sh. References:

• setenv - Linux setenv command help and examples1
• TZ - FreeBSD Environment Variables2

The pgrep command is used to find processes by various criteria, such as user name, group name, process ID, command name, etc. The -u option specifies the user name or user ID to match. Therefore, the command pgrep -u bob will show all processes owned by the user bob. The output will be a list of process IDs, one per line. To show more information about the processes, such as command name, arguments, state, etc., the -l, -a, and -f options can be used. For example, the command pgrep -l -u bob will show the process ID and the command name for each process owned by bob. References:

• pgrep - FreeBSD, the manual page for the pgrep command on FreeBSD.
• How to use pgrep and pkill commands in Linux - Linuxize, a tutorial on how to use the pgrep and pkill commands in Linux.

The -e option of the crontab command opens the current user’s crontab in an editor. The editor used is determined by the environment variables VISUAL or EDITOR. If neither of these variables is set, the default editor is vi. The user can edit the crontab file to add, modify, or delete cron jobs, which are scheduled commands or scripts that run at a specified time or interval. The crontab file has the following format:

minute hour day-of-month month day-of-week command

Each field can be a number, a range, a list, or an asterisk (*), which means all possible values. The command can be any valid shell command or script. For example, the following crontab entry runs the backup.sh script every day at 2:30 AM:

30 2 * * * /home/user/backup.sh

To save and install the crontab file, the user needs to exit the editor. The crontab command will check the syntax of the file and report any errors. If the file is valid, it will be installed and the cron daemon will execute the cron jobs according to the schedule. References:

• crontab(1) - Linux manual page
• FreeBSD Handbook: 11.6. Scheduling Tasks