Pass the LPI BSD Specialist 702-100 Questions and answers with ExamsMirror

To update FreeBSD, the freebsd-update fetch command is used to download available binary updates, and the freebsd-update install command is used to apply the downloaded updates to the system. These commands are part of the freebsd-update utility, which supports binary security and errata updates to the FreeBSD base system without the need for manual compilation and installation2.

References:

FreeBSD Handbook - freebsd-update

The cron job syntax consists of five fields that specify the time and date of execution, followed by the command or script to run. The fields are: minute, hour, day of month, month, and day of week. Each field can have a specific value, a range, a list, a wildcard (), or a step value. The wildcard () means any possible value for that field. The option B sets the minute field to 0 and the hour field to *, which means the script will run at the 0th minute of every hour, regardless of the day, month, or weekday. This is equivalent to once per hour. The other options are either invalid syntax or do not match the desired frequency. For example, option A sets all fields to *, which means the script will run every minute of every hour of every day, month, and weekday. Option C sets the minute field to * and the hour field to 0, which means the script will run every minute of the 0th hour, or once per day at midnight. Option D has a typo (o instead of *) and option E sets the day of month field to o, which is not a valid value. References:

crontab - FreeBSD crontab(5) Manual Page1

Crontab Explained in Linux [With Examples] - Linux Handbook2

The nice command is used to run a command with a modified scheduling priority, which affects how much CPU time the command receives. The priority can be specified by the -n option, which takes an integer value between -20 and 19, where lower values indicate higher priority. By default, the nice value is incremented by 10, which means the command runs with lower priority than normal. Only the superuser can specify a negative increment, which means the command runs with higher priority than normal. For example, the command nice -n 5 date runs the date command with a priority of 5, while the command nice -n -10 ls runs the ls command with a priority of -10, but only if the user is the superuser. The nice command is useful for running CPU-intensive commands that do not need to finish quickly, or for running commands that need more CPU time than normal. References:

nice - FreeBSD, the manual page for the nice command on FreeBSD.

HowTo: Use ps, kill, nice, and killall To Manage processes in FreeBSD and OS X Unix Operating System - nixCraft, a tutorial on how to use the nice command and other process management commands on FreeBSD and OS X.

The file /etc/hostname.em0 contains the configuration for the network interface em0 on an OpenBSD system. This file specifies the IP address, netmask, gateway, and other options for the interface. The file is read by the netstart script during boot or when the interface is restarted. The file name is derived from the interface name, which is usually based on the driver name and the device number. For example, em0 is the first interface using the em driver, which supports Intel PRO/1000 network adapters.

References:

Networking | OpenBSD Handbook

[hostname.if(5) - OpenBSD manual pages]

The /etc/fstab file contains information about the file systems that are mounted automatically at boot time or by the mount command. The file has six fields separated by whitespace: device, mount point, file system type, mount options, dump frequency, and pass number. The correct answer is D because it specifies the device (/dev/cd0a), the mount point (/cdrom), the file system type (cd9660), the mount option (ro for read-only), and the dump frequency and pass number (both 0 for no backup or fsck). The other answers are incorrect because they either have the wrong syntax, the wrong order of fields, or the wrong file system type. References:

BSD Specialist Exam 702 Objectives, Topic 715: Basic Unix Skills, 715.2 File and Directory Management

FreeBSD Handbook, Chapter 3: FreeBSD Basics, 3.8.2 Mounting and Unmounting File Systems

The swapctl command is used to list, add, or delete swap devices on BSD systems. It can also display the total amount of swap space available and used. The swapctl command takes various options to perform different actions, such as -l to list the swap devices, -a to add a swap device, -d to delete a swap device, and -s to show the swapsummary. The other options are not valid BSD commands for managing swap devices. References:

swapctl(8) - OpenBSD manual pages

FreeBSD Handbook - Chapter 19. The FreeBSD Booting Process

FreeBSD Handbook - Chapter 9. Configuring the FreeBSD Kernel

The mailer.conf file is used to configure the mailer programs on a BSD system. It allows the system administrator to replace the default mailer programs, such as sendmail, with alternative ones, such as postfix or exim. The mailer.conf file contains a series of entries, each consisting of a label, an equal sign, and a command. The label is the name of the default mailer program, and the command is the path to the alternative mailer program that will be executed instead. For example, to replace sendmail with postfix, the mailer.conf file should contain the following entries:

sendmail /usr/local/sbin/sendmail send-mail /usr/local/sbin/sendmail mailq /usr/local/sbin/sendmail newaliases /usr/local/sbin/sendmail hoststat /usr/local/sbin/sendmail purgestat /usr/local/sbin/sendmail

The mailer.conf file is read by the mailwrapper program, which is a binary that acts as a wrapper for the mailer programs. The mailwrapper program is installed as /usr/sbin/sendmail and /usr/libexec/sendmail/sendmail, and it invokes the appropriate mailer program based on the mailer.conf file. Therefore, to replace the system MTA with another mail server program, the mailer.conf file needs to be updated with the path to the new MTA. References:

Chapter 31. Electronic Mail | FreeBSD Documentation Portal

DragonFlyBSD: mta

In FreeBSD, theunamecommand is used to display system information. The option-vspecifically displays the version of the running operating system. This information is critical for system administrators and users who need to know the exact version of the OS they are working with, particularly when troubleshooting, updating, or configuring the system for specific software requirements.

https://man.freebsd.org/cgi/man.cgi?query=uname &sektion=1&format=html

The -v or --version option of the uname command displays the version level of the operating system. This is a string that identifies the release date and patch level of the system. For example, on FreeBSD, the output would be something like:

FreeBSD 13.0-RELEASE-p4 #0: Tue Aug 24 07:12:34 UTC 2021

This indicates that the system is running FreeBSD 13.0, with the fourth patch applied, and that the kernel was built on August 24, 2021. The version level can be useful to determine the compatibility and security of the system, as well as to report bugs or issues.

The question mark (?) is a special character in regular expressions that modifies the preceding expression to match zero or one times. For example, the regular expression colou?r matches both color and colour, but not colouur or colr. The question mark is also used to make an expression non-greedy, meaning that it will match the shortest possible string instead of the longest. For example, the regular expression <.?> matches the first pair of angle brackets in a string, while <.> matches the entire string enclosed by the outermost pair of angle brackets. References:

Regular expression - Wikipedia, section “Basic concepts”

How to write Regular Expressions? - GeeksforGeeks, section “Special Characters”

The command df -h displays the disk space usage of all mounted filesystems in a human-readable format. It shows the size, used, available, and percentage of each filesystem, as well as the mount point. This command can be used to check the local filesystems that are currently mounted.

https://unix.stackexchange.com/questions/24182/how-to-get-the-complete-and-exact-list-of-mounted-filesystems-in-linux

https://www.tecmint.com/find-mounted-file-systems-in-linux/

https://itslinuxfoss.com/check-filesystem-mounted-linux/