101-500 Exam Results

 The find command can be used to search for files and directories that match certain criteria, such as ownership, permissions, size, type, name, etc. The syntax of the find command is:

find [options] [path...] [expression]

The options can modify the behavior of the find command, such as how to handle symbolic links, how to optimize the search, or how to enable debugging. The path argument specifies the starting point of the search, which can be one or more directories. The expression argument consists of one or more tests, actions, and operators that are applied to each file or directory that is found.

The -user test matches files or directories that are owned by a given user. The user can be specified by name or by numeric user ID (UID). The -print action prints the full file name of the matching file or directory on the standard output, followed by a newline. If no action is specified, -print is assumed by default.

Therefore, to list all files and directories within the /tmp/ directory and its subdirectories which are owned by the user root, we can use either of the following commands:

• find /tmp -user root -print
• find /tmp -user root

Both commands will search recursively from the /tmp/ directory and print the full file names of the files or directories that are owned by the user root. The -print action is optional in this case, since it is the default action.

The other commands are incorrect for the following reasons:

• find -path /tmp -uid root : The -path test matches files or directories whose full file name matches the given pattern. This command will not search recursively from the /tmp/ directory, but only match files or directories whose name is exactly /tmp. The -uid test is equivalent to the -user test, but it requires a numeric UID instead of a user name. This command will not match any files or directories, unless there is a file or directory named /tmp that is owned by the user with UID root (which is usually 0).
• find -path /tmp -user root -print : This command has the same problem as the previous one. It will not search recursively from the /tmp/ directory, but only match files or directories whose name is exactly /tmp and are owned by the user root. This command will not match any files or directories, unless there is a file or directory named /tmp that is owned by the user root.
• find /tmp -uid root -print : This command will search recursively from the /tmp/ directory, but it will use the -uid test instead of the -user test. The -uid test requires a numeric UID instead of a user name. This command will match files or directories that are owned by the user with UID root (which is usually 0), but it will not match files or directories that are owned by other users who have the same user name as root (such as root2 or root3).

References:

• find(1) - Linux manual page - man7.org
• How to Use the find Command in Linux - How-To Geek
• find command in Linux with examples - GeeksforGeeks
• find | Microsoft Learn
• Linux Find Command Help and Examples - Computer Hope

The correct answer is C, 2dd. This command will delete two lines, the current and the following line, in vi editor. The syntax of the command is:

[number]dd

The number specifies how many lines to delete, starting from the current line. The dd command deletes the lines and puts them in a buffer, which can be pasted later with the p command. If no number is given, the command will delete only the current line.

The other commands are incorrect for the following reasons:

• A, d2: This command will delete two characters, not two lines. The syntax of the command is:

d[motion]

The motion specifies how many characters to delete, starting from the current cursor position. The 2 motion means two characters to the right. The d command deletes the characters and puts them in a buffer, which can be pasted later with the p command.

• B, 2d: This command is incomplete and will not work. The d command requires a motion argument to specify how many characters to delete. The 2 argument is only a number, not a motion. The command will wait for another keystroke to complete the motion.
• D, dd2: This command will delete the current line and then move the cursor two lines down. The syntax of the command is:

dd[number]

The dd command deletes the current line and puts it in a buffer, which can be pasted later with the p command. The number specifies how many lines to move the cursor down, after deleting the current line. If no number is given, the command will move the cursor to the next line.

• E, de12: This command will delete from the current cursor position to the end of the word, and then move the cursor to the 12th line. The syntax of the command is:

d[motion][number]

The d command deletes the characters specified by the motion and puts them in a buffer, which can be pasted later with the p command. The e motion means the end of the word. The number specifies the line number to move the cursor to, after deleting the characters.

References:

• vi/vim delete commands and examples | alvinalexander.com
• How to Delete Lines in Vim / Vi | Linuxize
• How can I delete multiple lines in vi? - Stack Overflow

 The EFI System Partition (ESP) is a special partition on a disk that contains the UEFI boot loaders, applications and drivers for the installed operating systems. The UEFI firmware will load these files from the ESP when the system boots. The ESP is mandatory for UEFI boot and it is usually formatted with a FAT file system. The ESP is part of the 101.1 Determine and configure hardware settings topic of the LPI Linux Essentials certification program12.

The other options are false or irrelevant. The Linux root file system is not contained on the ESP, it is usually on a separate partition with a Linux file system, such as ext4 or btrfs. The default swap space file is not contained on the ESP, it is usually on a swap partition or a swap file on the Linux root file system. The Linux default shell binaries are not contained on the ESP, they are usually on the /bin directory of the Linux root file system. The user home directories are not contained on the ESP, they are usually on the /home directory of the Linux root file system or on a separate partition. References:

• Linux Essentials - Linux Professional Institute Certification Programs1
• Exam 101 Objectives - Linux Professional Institute2
• EFI system partition - ArchWiki3
• /boot/efi Linux partition: What is, usage recommendations

 The action that ensures that a faulty kernel module is not loaded automatically when the system boots is adding a blacklist line including the name of the offending module to the file /etc/modprobe.d/blacklist.conf. This file contains a list of kernel modules that are prevented from loading by the modprobe command, which is used to load and unload modules from the running kernel. By adding a line like blacklist  to this file, the module will be ignored by modprobe unless it is explicitly specified as aparameter. This way, the module will not be loaded at boot time or by other modules that depend on it. The other options are either invalid or do not affect the automatic loading of the module. Using lsmod --remove --autoclean without specifying the name of a specific module will not work, because lsmod does not have such options and it is only used to display the currently loaded modules. Using modinfo –k followed by the name of the offending module will not work, because modinfo does not have a -k option and it is only used to display information about a module. Using modprobe –r followed by the name of the offending module will only remove the module from the running kernel, but it will not prevent it from loading again at the next boot. Deleting the kernel module’s directory from the file system and recompiling the kernel, including its modules, is a drastic and unnecessary measure that will not only remove the faulty module, but also all other modules in that directory, and it will require a lot of time and expertise to perform. References:

• Linux Essentials - Linux Professional Institute Certification Programs1
• Exam 101 Objectives - Linux Professional Institute2
• Linux Kernel Module Management 101 - Linux.com1
• Chapter 2. Managing kernel modules - Red Hat Customer Portal2