LPI 101-500 Exam Dumps - Actual Questions Answers

The directories on a 64 bit Linux system that typically contain shared libraries are /usr/lib64/ and /lib64/. Shared libraries are binary files that provide reusable functions, routines, classes, data structures, and so on for programs and applications. They are loaded into memory before the program starts and shared by multiple processes that use the same library. Shared libraries are usually stored in standard locations in the file system, such as /usr/lib, /usr/local/lib, /lib, and /lib64 for 32 bit systems, and /usr/lib64, /usr/local/lib64, /lib64, and /lib for 64 bit systems12. The /usr/lib64 and /lib64 directories contain the shared libraries for the system and user applications, respectively. The other directories are either non-existent or do not contain shared libraries. The ~/.lib64/ directory is not a standard location for shared libraries, and it is unlikely that a user would have such a directory in their home directory. The /var/lib64/ directory is also not a standard location for shared libraries, and it is usually used for variable data files that are specific to a package or application. The /opt/lib64/ directory is not a standard location for shared libraries, and it is usually used for optional software packages that are installed in the /opt directory3. References:

• Linux Essentials - Linux Professional Institute Certification Programs1
• Exam 101 Objectives - Linux Professional Institute2
• Understanding Shared Libraries in Linux - Tecmint3

 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

This command will display the path to the executable file that would be executed when the command foo is invoked. The syntax of the command is:

which [options] command

The which command is a utility that searches the directories listed in the PATH environment variable for the executable file that matches the given command. The options can modify the behavior of the which command, such as displaying all matches, ignoring aliases, or showing the version. The command is the name of the command to be located.

Therefore, the command which foo will search the PATH directories for the executable file named foo and print its full path on the standard output. If there are multiple matches, the command will print the first one found. If there is no match, the command will print nothing and return an exit status of 1.

The other commands are incorrect for the following reasons:

• A, lsattr foo: This command will not display the path to the executable file, but it will display the file attributes of the file named foo in the current directory. The syntax of the command is:

lsattr [options] [file]

The lsattr command is a utility that lists the file attributes on a Linux second extended file system. The options can modify the behavior of the lsattr command, such as displaying the output in long format, recursing into subdirectories, or suppressing errors. The file is the name of the file whose attributes are to be listed. If no file is given, the command will list the attributes of all files in the current directory.

Therefore, the command lsattr foo will list the file attributes of the file named foo in the current directory, if it exists. If it does not exist, the command will report an error and return an exit status of 1.

• B, apropos foo: This command will not display the path to the executable file, but it will display a list of manual page names and descriptions that contain the keyword foo. The syntax of the command is:

apropos [options] keyword

The apropos command is a utility that searches the whatis database for the keyword and prints the manual page names and descriptions that match. The whatis database is a set of files containing short descriptions of system commands and programs. The options can modify the behavior of the apropos command, such as using regular expressions, ignoring case, or displaying the section numbers. The keyword is the word to be searched in the whatis database.

Therefore, the command apropos foo will search the whatis database for the word foo and print the manual page names and descriptions that contain it. If there are no matches, the command will print nothing and return an exit status of 1.

• C, locate foo: This command will not display the path to the executable file, but it will display a list of file names that contain the string foo. The syntax of the command is:

locate [options] pattern

The locate command is a utility that searches a database of file names and prints the file names that match the given pattern. The database is updated periodically by the updatedb command and may not reflect the current state of the file system. The options can modify the behavior of the locate command, such as using regular expressions, ignoring case, or limiting the number of results. The pattern is the string to be matched in the file names.

Therefore, the command locate foo will search the database of file names and print the file names that contain the string foo. If there are no matches, the command will print nothing and return an exit status of 1.

• D, whatis foo: This command will not display the path to the executable file, but it will display a short description of the command or program named foo. The syntax of the command is:

whatis [options] name

The whatis command is a utility that searches the whatis database for the name and prints the manual page name and description that match. The whatis database is a set of files containing short descriptions of system commands and programs. The options can modify the behavior of the whatis command, such as displaying the section numbers, using wildcards, or searching in a specific section. The name is the name of the command or program to be described.

Therefore, the command whatis foo will search the whatis database for the name foo and print the manual page name and description that match. If there are no matches, the command will print nothing and return an exit status of 1.

References:

• Which Command in Linux [Explained with Examples]
• How to Use the which Command on Linux - How-To Geek
• which command in Linux with examples - GeeksforGeeks
• How to Use the which Command in Linux - phoenixNAP