LPI 102-500 - LPIC-1 Exam 102, Part 2 of 2, version 5.0

The command that is used to sync the hardware clock to the system clock is:

hwclock --systohc

This command copies the current system time to the hardware clock, which runs even when the system is shut down. It is equivalent to the command hwclock -w12. The hardware clock is also called the BIOS clock or the RTC (Real Time Clock)3.

The command lpq can be used to display the status of the printer’s queue on a Linux server. The lpq command is part of the cups-bsd package, which provides the Berkeley commands for CUPS (Common UNIX Printing System), the standard printing system for Linux. The lpq command shows the status of a specified printer or the default printer if none is specified. It also lists the jobs that are queued for printing, along with their job IDs, owners, sizes, and names12. For example, to display the status of the printer lp1, we can use the following command:

$ lpq -P lp1

lp1 is ready

Rank Owner Job File(s) Total Size

active user1 123 test.txt 1024 bytes

1st user2 124 report.pdf 2048 bytes

The output shows that the printer lp1 is ready, and that there are two jobs in the queue, one of which is active and the other is waiting. The output also shows the owners, job IDs, file names, and sizes of the jobs. To display the status of all printers, we can use the -a option:

$ lpq -a

lp1 is ready

Rank Owner Job File(s) Total Size

active user1 123 test.txt 1024 bytes

1st user2 124 report.pdf 2048 bytes

lp2 is ready

no entries

The output shows that there are two printers, lp1 and lp2, and that lp2 has no entries in the queue. To display more information about the jobs, such as the priority, submission time, and status, we can use the -l option:

$ lpq -l -P lp1

lp1 is ready

Rank Owner Job File(s) Total Size

active user1 123 test.txt 1024 bytes

priority 50 Apr 27 10:00 processing since Apr 27 10:01

1st user2 124 report.pdf 2048 bytes

priority 50 Apr 27 10:05 waiting for lp1

The output shows that the jobs have the same priority, and that the first job is processing while the second job is waiting. The lpq command can be useful for troubleshooting printing problems, such as checking if the printer is ready, if there are any stuck or failed jobs, or if there are any conflicts or delays in the queue34. References: 1: lpq(1) - Linux manual page 2: How to Use the lp Command in Linux to Print Files From Terminal - Make Tech Easier 3: Linux sysadmin printing reference guide - PenguinTutor 4: How to manage print jobs on Linux - Network World

The /etc/cron.allow and /etc/cron.deny files are used to control access to the crontab command and cron jobs for individual users. If neither of these files exists, then depending on site-dependent configuration parameters, only the superuser (root user) will be allowed to use this command, or all users will be able to use this command1. The default behavior of most Linux distributions is to allow all users to use the crontab command and have user specific crontabs if neither /etc/cron.allow nor /etc/cron.deny exists23. Therefore, option B is the correct answer. The other options are not true because:

Option A is false because it contradicts the default behavior of most Linux distributions.

Option C is false because the cron daemon will not refuse to start or report missing files in the system’s logfile if neither /etc/cron.allow nor /etc/cron.deny exists. The cron daemon will start normally and use the default configuration parameters1.

Option D is false because the system administrator does not need to approve user specific crontabs explicitly. The user can create, edit, display, or remove their own crontab files without any intervention from the system administrator1. References:

How cron.allow and cron.deny can be used to limit access to crontab for a particular user | The Geek Search

crontab(1) — cron — Debian bullseye — Debian Manpages

Controlling Access to crontab (System Administration Guide: Basic Administration) - Oracle

/etc/cron.allow - Linux Bash Shell Scripting Tutorial Wiki - nixCraft

The /usr/share/zoneinfo directory contains the binary time zone files that are used by the system to determine the local time for any region. The files are organized in subdirectories by continent, country, or ocean. Some files represent the standard time zones, while others may have historical or political variations. To set the system’s timezone, one can create a symbolic link from /etc/localtime to the appropriate file in the /usr/share/zoneinfo directory. For example, to set the timezone to America/New_York, one can use the command sudo ln -sf /usr/share/zoneinfo/America/New_York /etc/localtime. Alternatively, one can use the timedatectl command to set the timezone without creating the link manually. References:

How to Set or Change the Time Zone in Linux | Linuxize

4 Ways to Change the Timezone in Linux - wikiHow

The chage command can be used to change the expiration date of a user account. By setting the expiration date to a past date, the user account will be disabled and the user will not be able to login interactively. This is a temporary method, as the expiration date can be changed back to a future date or removed to re-enable the user account. The other options are either permanent, insecure, or ineffective. Option A is insecure, as it allows anyone to login as the user without a password. Option C is permanent, as it changes the user’s password without saving the original one. Option D is ineffective, as it only affects the user’s .login file, which is used by the csh and tcsh shells, and not by other shells such as bash or zsh. Therefore, option B is the best method to temporarily suspend a user’s ability to interactively login. References: https://linuxconfig.org/disabling-user-logins-to-linux-system

https://askubuntu.com/questions/282806/how-to-enable-or-disable-a-user

 The commands that should be added to /etc/bash_profile to change the language of messages from an internationalised program to Portuguese (pt) are:

export LANG=“pt”

export LC_MESSAGES=“pt”

 The LANG and LC_MESSAGES environment variables are used to control the language of messages from an internationalised program. The LANG variable sets the default locale for all categories, such as collation, currency, date and time formats, etc. The LC_MESSAGES variable sets the locale for the language of messages, overriding the LANG variable for this category. Therefore, to change the language of messages to Portuguese, both variables should be set to “pt” in /etc/bash_profile, which is a script that is executed when a user logs in. This will affect the current user and any subsequent login sessions.

References:

Locale Environment Variables in Linux – Baeldung on Linux

Environment Variables - The Open Group

[LPI Linux Essentials - 1.4 Localization and Internationalization]

The iconv command is used to convert the encoding of a file from one character set to another. A character set is a collection of characters that are assigned numerical values called code points. Different character sets may use different numbers of bytes to represent each character, and may have different mappings of code points to characters. For example, ASCII is a single-byte character set that encodes 128 characters, while UTF-8 is a variable-length character set that can encode over a million characters. The iconv command can convert between many different character sets, such as ASCII, UTF-8, ISO-8859-1, etc. The basic syntax for using the command is as follows:

iconv [options] -f from-encoding -t to-encoding input-file > output-file

The -f option specifies the encoding of the input file, and the -t option specifies the encoding of the output file. The input file is read from standard input, and the output file is written to standard output, unless specified otherwise. The iconv command can also list all the supported character sets with the -l option1234. References:

How To Use the iconv Command on Linux - How-To Geek

iconv command in Linux with Examples - GeeksforGeeks

iconv - convert file encoding from one character set to another | Linux …

Using iconv to change character encodings - FileFormat.Info

The crontab file format consists of six fields: minute, hour, day of month, month, day of week, and command. The user-specific crontab files have the same format as the global /etc/crontab file, except that they do not have the username field. The username field is only present in the system-wide crontab files and specifies which user will run the cron job. The year field is not a valid crontab field and is not supported by cron. References:

Scheduling Cron Jobs with Crontab | Linuxize

Crontab Explained in Linux [With Examples]

 The locale is a set of environmental variables that defines the language, country, and character encoding settings for the applications and shell session on a Linux system. The locale affects things such as the time/date format, the first day of the week, numbers, currency and many other values formatted in accordance with the language or region/country you set on a Linux system1. The currency sign (¤) is a character used to denote an unspecified currency2. To display the correct currency symbol for a specific region, the locale must be set accordingly. For example, to display the euro symbol (€) for France, the locale can be set to fr_FR.UTF-81. Setting the timezone correctly, editing /etc/currency, or reinstalling the French language pack will not affect the currency symbol displayed in the spreadsheets. References: 1: How to Change or Set System Locales in Linux - Tecmint 2: decimal.ToString (“C”) produces ¤ currency symbol on Linux - Stack Overflow

The command userdel --force --remove bob is used to delete the user account named bob and all its associated files. The --force option forces the removal of the user account, even if the user is still logged in. The --remove option forces userdel to remove the user’s home directory and mail spool, even if another user uses the same home directory or if the mail spool is not owned by the specified user12. Therefore, options A and B are true regarding this command.

The other options are not true because:

Option C is false because the locate database is not updated by the userdel command. The locate database is updated by the updatedb command, which is usually run by cron as a scheduled job3.

Option D is false because the userdel command does not remove all files owned by bob from all mounted filesystems. The userdel command only removes the user’s home directory and mail spool, and it does not search for and delete the user files located in other file systems. You have to search for and delete the files manually1.

Option E is false because the userdel command does not delete the group with the same name as the user, unless the USERGROUPS_ENAB parameter is set to yes in the /etc/login.defs file and the group has no other members14.

References:

How to Delete/Remove Users in Linux (userdel Command) | Linuxize

userdel(8) — Linux manual page

updatedb(8) — Linux manual page

Understanding the /etc/login.defs File | Linuxize