101-500 Practice Questions

The <, > and %> are valid stream redirection operators within Bash. The < operator redirects the standard input of a command from a file or another command. For example, sort < names.txt will sort the lines of the file names.txt and print them to the standard output. The > operator redirects the standard output of a command to a file or another command, overwriting the file if it exists. For example, echo "Hello World" > greeting.txt will write the string “Hello World” to the file greeting.txt. The %> operator redirects the standard error of a command to a file or another command, overwriting the file if it exists. For example, ls foo %> errors.log will list the contents of the directory foo and write any error messages to the file errors.log. The other options are either invalid or do not perform the desired task. The <<< operator is not a valid Bash operator, but it is used in some other shells like Zsh to redirect a string literal as the standard input of a command. The >>> operator is not a valid Bash operator, but it is used in some programming languages like Python to denote a bitwise right shift operation. References:

LPIC-1 Exam 101 Objectives, Topic 103: GNU and Unix Commands, 103.4 Use streams, pipes and redirects

LPIC-1 Linux Administrator 101-500 Exam FAQ, LPIC-1 Exam 101 Objectives, GNU and Unix Commands (Total Weight: 25)

The yum command is a tool for managing software packages on Red Hat Enterprise Linux and other RPM-based systems. The yum update option will update the entire system by checking the versions of the installed packages and installing the latest available versions from the repositories. The yum upgrade option will do the same, but it will also remove any obsolete packages that are no longer needed by the system. Both options will prompt the user to confirm before proceeding with the update or upgrade process. References:

Yum Command Cheat Sheet for Red Hat Enterprise Linux

"yum update" Explained for Beginners!

How to Install Updates on CentOS 7

Which option to the yum command will update the entire system?

The swapoff command is used to disable swapping on a device or a file. It takes the path of the device or file as an argument, or -a to disable all swaps. Disabling swap can improve the performance of the system if there is enough physical memory, or it can be necessary if the swap size needs to be changed. However, disabling swap can also cause problems if the system runs out of memory and has no swap space to use. References:

How to Disable Swap in Linux - Linux Handbook

How to Permanently Disable Swap in Linux? - GeeksforGeeks

LPI Linux Essentials - 1.1 Operating System Basics