LPI Updated 102-500 Exam Questions and Answers by mariam

The logger command can be used to generate syslog entries of any facility and priority. It is a shell command interface to the syslog system log module. It allows users to write messages to the system log from the command line or from a script. The logger command supports several options to specify the facility, priority, tag, message, and other attributes of the log entry. For example, the following command generates a log entry with the facility user and the priority info:

logger -p user.info “This is a test message”

The facility and priority can be any of the values defined in the syslog protocol, such as kern, mail, auth, local0, etc. for the facility, and emerg, alert, crit, err, warn, notice, info, debug, etc. for the priority. The default facility is user and the default priority is notice. The logger command can also read messages from standard input or from a file. For more information, see the logger man page or the logger - Linux man page online. References:

Syslogs in Linux: Understanding Facilities and Levels

What are Syslog Facilities and Levels? - Trend Micro

syslog-ng Open Source Edition 3.30 - Administration Guide

Syslog Logging Guide: Advanced Concepts - CrowdStrike

 The syslog facilities are predefined categories of messages that can be used to classify the source and type of the log events12. The syslog facilities are defined by the syslog protocol and are standardized across different implementations of syslog12. The syslog facilities are:

auth: Security and authorization messages, such as login failures or sudo usage12.

authpriv: Same as auth, but used for private security messages that should not be available to all users12.

cron: Messages from the cron daemon, such as scheduled jobs or errors12.

daemon: Messages from system daemons, such as sshd or ntpd12.

kern: Messages from the kernel, such as boot messages or hardware errors12.

lpr: Messages from the line printer subsystem, such as print jobs or errors12.

mail: Messages from the mail subsystem, such as sendmail or postfix12.

news: Messages from the network news subsystem, such as news servers or clients12.

syslog: Messages generated internally by the syslog daemon, such as configuration errors or restarts12.

user: Messages from user-level processes, such as applications or scripts12.

uucp: Messages from the Unix-to-Unix copy subsystem, such as file transfers or errors12.

local0 to local7: Custom facilities that are not used by any system processes and can be assigned to user applications or scripts123.

Therefore, the correct answers are A. local7 and B. mail, as they are both valid syslog facilities. The other options are not syslog facilities and are either made up (C. advanced and E. remote) or refer to a specific process rather than a category of messages (D. postmaster).

References: 1: Prepare for LPIC-1 exam 2 - topic 108.2: System logging - IBM Developer Tutorial 2: 108.2 System logging - Linux Professional Institute Certification Programs 3: What is the local6 (and all other local#) facilities in syslog?

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 date command is used to display and set the system date and time. It can also be used to print the time in different formats and calculate future and past dates. The date command has the following syntax:

date [option]... [+format]

The format controls begin with the % symbol and are substituted by their current values. For example, to display the current year, month, and day, we can use the following command:

date +"Year: %Y, Month: %m, Day: %d"

To set the system clock manually, we can use the --set or -s option followed by the date and time string. For example, to set the date and time to 5:30 PM, May 13, 2010, we can use the following command:

date --set="20100513 05:30"

The other tasks are not possible with the date command because:

Synchronize the hardware and system clocks: The date command cannot synchronize the hardware and system clocks. To do this, we need to use the hwclock command, which can read or set the hardware clock, and also synchronize it with the system clock.

Set the hardware clock: The date command cannot set the hardware clock. To do this, we need to use the hwclock command with the --systohc or -w option, which will copy the system time to the hardware clock.

Update the time via NTP: The date command cannot update the time via NTP (Network Time Protocol). To do this, we need to use the ntpdate command, which will query an NTP server and set the system clock accordingly.

References:

Date Command in Linux: How to Set, Change, Format and Display Date

date command in Linux with examples - GeeksforGeeks

Date Command in Linux | Linuxize