LPI 102-500 Dumps

 The top-level directory which contains the configuration files for CUPS is /etc/cups. CUPS stands for Common UNIX Printing System, which is the printer and print job manager for Linux. The /etc/cups directory contains several configuration files related to CUPS, such as cupsd.conf, which is the main configuration file for the cupsd print server daemon, and printers.conf, which contains the definition of the printers. The /etc/cups directory is part of the topic 108.4: Manage printers and printing, which is one of the objectives of the LPI Linux Administrator - 102 exam12. References: 1: LPI Linux Administrator - 102 (LPIC-1) 2: Exam 102 Objectives

The command that displays all environment and shell variables is env. The env command prints a list of the current environment variables, which are variables that are defined for the current shell and are inherited by any child shells or processes. The env command can also be used to run another program in a custom environment without modifying the current one1. The env command is part of the GNU coreutils package and is available on most Linux systems2.

The other commands are not valid or do not display all environment and shell variables. The getargs command does not exist in Linux. The lsenv command is a utility to list information about IBM Power Systems firmware, not environment variables. The ls command lists the files and directories in the current working directory, not environment variables. The lsshell command is a utility to list the available shells on a system, not environment variables.

References:

LPI Linux Essentials: 1.4. Using sudo

LPI Linux Administrator: 102.5. Use Debian package management

LPI Linux Engineer: 201.1. Measure and Troubleshoot Resource Usage

LPI Linux Professional Certification Program

https://linuxconfig.org/how-to-set-and-list-environment-variables-on-linux

https://www.digitalocean.com/community/tutorials/how-to-read-and-set-environmental-and-shell-variables-on-linux

https://unix.stackexchange.com/questions/176001/how-can-i-list-all-shell-variables

 On a Linux system with shadow passwords enabled, the file that contains the password hashes of all local users is /etc/shadow. This file is a replacement for the password field in /etc/passwd, which is a world-readable file that contains basic information about users. The /etc/shadow file is not readable by regular users, and it stores the encrypted passwords (or hashes) of each user, along with other information such as password expiration dates, minimum and maximum password ages, and password warning periods. The /etc/shadow file has nine colon-delimited fields for each user:

Username: The name used when the user logs into the system.

Password: The encrypted password of the user, or a special character that indicates the password status. For example, an asterisk (*) means the account is locked, and an exclamation mark (!) means the password is expired.

Last Password Change: The date of the last password change, expressed as the number of days since January 1, 1970.

Minimum Password Age: The minimum number of days required between password changes. A zero means the password can be changed anytime.

Maximum Password Age: The maximum number of days the password is valid. After this number of days, the password must be changed. A zero means the password never expires.

Password Warning Period: The number of days before the password expires that the user will be warned. A zero means no warning is given.

Password Inactivity Period: The number of days after the password expires that the account will be disabled. A negative value means the account is never disabled.

Account Expiration Date: The date when the account will be disabled, expressed as the number of days since January 1, 1970. A zero means the account never expires.

Reserved Field: A field for future use.

The /etc/shadow file can be modified by using the commands passwd and chage, which are used to change the password and the password aging information of a user, respectively. The /etc/shadow file should not be edited directly, but always through the tools provided by the distribution. For more details, see the shadow manual page.

References:

LPIC-1 Exam 102 Objectives, Topic 110: Security, Subtopic 110.2: Use sudo to manage access to the root account, Weight: 2, Key Knowledge Areas: Configure sudo and sudoers. Use sudo to execute commands as another user.

LPIC-1 Exam 102 Learning Materials, Topic 110: Security, Subtopic 110.2: Use sudo to manage access to the root account, Section 110.2.1: sudo and sudoers, Page 3-5.