LPI 101-500 Based on Real Exam Environment

 The nice command is used to start another command with a given nice level. The nice level is a value that affects the scheduling priority of a process. A lower nice level means a higher priority, and a higher nice level means a lower priority. The default nice level is 0, and the range is from -20 to 19. Only the superusercan assign a negative nice level to a process. The nice command can also be used to display the current nice level of a process by using the -n option. References:

• LPI 101-500 Exam Objectives, Topic 103.3, Weight 3
• LPI Learning Materials, Chapter 3.3, Process Management
• Web Search Results, 1

The command rpm -qpl apache-ql.rpm is used to preview the list of files that would be installed by the RPM package file apache-xml.rpm. This command queries the package file without installing it and lists the contents of the package. Here’s what each part of the command means:

• rpm is the command-line tool used for managing RPM packages on Linux systems.
• -qpl are options for the rpm command.
• apache-xml.rpm is the name of the RPM package file you want to query.

So, when you run this command, it will display a list of all the files that are included in the apache-xml.rpm package file, without installing it. This can be useful for checking what files are included in the package before installing it or comparing it with another version of the package.

The other commands are either invalid or do not perform the same function as the correct answer. For example:

• rpm -qp apache-xml.rpm will only display the name and version of the package, not the list of files.
• rpm -qv apache-xml.rpm will display the verbose information about the package, such as the description, license, and changelog, but not the list of files.
• rpm -ql apache-xml.rpm will list the files that are installed on the system by the apache-xml.rpm package, but only if the package is already installed. If the package is not installed, it will return an error.

References:

• 4 ways to list files within a rpm package in Linux
• How to list all files installed by RPM package
• How to List Files Installed From an RPM Package in CentOS?
• How to list all files contained in an RPM package

The correct commands to display all currently mounted filesystems are cat /proc/self/mounts and mount. The cat /proc/self/mounts command reads the contents of the /proc/self/mounts file, which is a symbolic link to /proc/mounts. This file contains information about all the filesystems that are currently mounted on the system, as reported by the kernel. The mount command without any arguments shows all the mounted filesystems, as recorded by the mount and umount commands. The other options are incorrect because they do not display the mounted filesystems. The free command shows the amount of free and used memory in the system. The lsmounts command is not a standard Linux command. The cat /proc/filesystems command shows the filesystem types that are supported by the kernel. References:

• [LPI Linux Essentials - 2.2 Mounting, Unmounting Filesystems]
• How to get the complete and exact list of mounted filesystems in Linux? - Unix & Linux Stack Exchange
• 4 Commands to List Mounted File Systems in Linux - Linux Shell Tips
• How To Show Mounted Devices In Linux Operating System
• How to Check if a Filesystem is Mounted in Linux?