Free Practice Questions for LPI 010-160 Exam

The passwd command in Linux is used to change the password of a user account. A normal user can run passwd to change their own password, and a system administrator (the superuser) can use passwd to change another user’s password, or define how that account’s password can beused or changed1. The passwd command can also be used to lock or unlock a user account. Locking a user account means disabling the user’s ability to log in to the system, while unlocking a user account means restoring the user’s ability to log in. To lock a user account, the passwd command can be used with the -l option, followed by the username. To unlock a user account, the passwd command can be used with the -u option, followed by the username12. The passwd command cannot be used to change a user’s username, create a new user account, or create a new user group. These tasks require different commands, such as usermod, useradd, orgroupadd345. References: 1: Linux Passwd Command Help and Examples 2: Passwd command in Linux: 8 Practical Examples 3: usermod(8) - Linux man page 4: useradd(8) - Linux man page 5: groupadd(8) - Linux man page

The chmod command is used to change the permissions of files and directories. The permissions are represented by three sets of three characters, indicating the permissions for the owner, the group, and the others. Each character can be either r (read), w (write), x (execute), or - (no permission). The chmod command can use either symbolic or numeric mode to specify the permissions. In this question, the numeric mode is used, which consists of three digits from 0 to 7. Each digit is the sum of the permissions for each set, where r is 4, w is 2, and x is 1. For example, 7 means rwx, 6 means rw-, and 4 means r–. Therefore, the command chmod 654 file.txt sets the permissions as follows:

The first digit 6 means rw- for the owner, which means the owner can read and write the file, but not execute it.

The second digit 5 means r-x for the group, which means the group can read and execute the file, but not write it.

The third digit 4 means r-- for the others, which means the others can only read the file, but not write or execute it.

The resulting permissions are -rw-r-xr–, which is the correct answer. The other options are incorrect because they either have the wrong permissions or the wrong file type. A regular file does not have the d (directory) prefix, and a directory cannot have the - (no file type) prefix. References:

Linux Essentials Version 1.6 Objectives: 4.1. Ownership and Permissions1

Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Chapter 8. Security and File Permissions - 8.1. Ownership and Permissions - 8.1.1. The chmod Command2

Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Appendix A. Answers to the Exercises - Chapter 8. Security and File Permissions - 8.1. Ownership and Permissions - Exercise 8.1.12

The backslash character () is used to escape the meaning of the next character in a command line. This means that the next character is treated as a literal character, not as a special character. For example, if you want to use a space in a file name, you can use a backslash before the space to prevent the shell from interpreting it as a separator. Similarly, if you want to split a long command line across multiple lines, you can use a backslash at the end of each line to tell the shell that the command is not finished yet. The shell will ignore the newline character and continue reading the next line as part of the same command. For example, you can write:

ls -l/home/user/Documents

instead of:

ls -l /home/user/Documents

Both commands will produce the same output, but the first one is easier to read and type. References:

Linux Essentials - Linux Professional Institute (LPI), section 2.1.2

2.1 Command Line Basics - Linux Professional Institute Certification Programs, slide 7.

 CentOS is a Linux distribution that is derived from Red Hat Enterprise Linux (RHEL). CentOS stands for Community Enterprise Operating System and it aims to provide a free, enterprise-class, community-supported computing platform that is functionally compatible with RHEL. CentOS is one of the most popular Linux distributions for servers and cloud computing. Raspbian, openSUSE, Debian and Ubuntu are other Linux distributions that are not derived from RHEL, but have their own origins and development histories. Raspbian is based on Debian and optimized for the Raspberry Pi. openSUSE is a community project sponsored by SUSE Linux and other companies. Debian is one of the oldest and most influential Linux distributions, and Ubuntu is derived from Debian and sponsored by Canonical Ltd. References:

Linux Essentials - Linux Professional Institute (LPI) 1

Linux Essentials Version 1.6 Update - Linux Professional Institute (LPI) 2

Free LPI 010-160 Questions - Pass LPI 010-160 - Pass4Success 3

LPI Linux Essentials Study Guide: Exam 010 v1.6, 3rd Edition 4

 Reverse DNS lookups query DNS servers for a PTR (pointer) record; if the server does not have a PTR record, it cannot resolve a reverse lookup. PTR records store IP addresses with their segments reversed, and they append “.in-addr.arpa” to that. For example, if a domain has an IP address of 192.0.2.1, the PTR record will store the domain’s information under 1.2.0.192.in-addr.arpa. In IPv6, the latest version of the Internet Protocol, PTR records are stored within the “.ip6.arpa” domain instead of ".in-addr.arpa."1 Therefore, the name of the IP address 198.51.100.165 is stored in the PTR record for 165.100.51.198.in-addr.arpa. References: 1: Reverse DNS lookup - Wikipedia 1

 The sort command is used to sort the lines of a text file or the output of another command in alphabetical, numerical, or other order. The sort command has the following syntax: sort [options] [file…]. The file argument is the name of one or more files to be sorted. If no file is given, the sort command reads from the standard input, which is usually the keyboard or the output of another command.

The | (pipe) symbol is used to connect the output of one command to the input of another command. This allows the creation of pipelines of commands that process data sequentially. The pipe symbol has the following syntax: command1 | command2. The command1 argument is the name of the first command, whose output is sent to the input of the second command. The command2 argument is the name of the second command, which receives the output of the first command as its input.

Therefore, the command export-logs | sort sorts the output of the export-logs command in alphabetical order. The export-logs command is assumed to be a custom command that exports some logs to the standard output. The sort command receives the output of the export-logs command as its input and sorts it according to the default criteria, which is the first character of each line. The sorted output is then displayed on the screen or can be redirected to a file or another command.

The other options in the question are incorrect because they use the wrong symbols to connect the commands. The < (input redirection) symbol is used to read the input of a command from a file instead of the keyboard. The > (output redirection) symbol is used to write the output of a command to a file instead of the screen. The & (background) symbol is used to run a command in the background, which means the command does not wait for user input and allows the user to run other commands simultaneously. The <> (bidirectional redirection) symbol is used to read and write the input and output of a command from and to the same file. None of these symbols can be used to sort the output of the export-logs command. References:

Linux Essentials Version 1.6 Objectives: 3.2. Searching and Extracting Data from Files1

Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Chapter 9. The Power of the Command Line - 9.2. Searching and Extracting Data from Files - 9.2.1. The sort Command2

Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Chapter 9. The Power of the Command Line - 9.3. Turning Commands into a Script - 9.3.1. Pipes and Redirection2

Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Appendix A. Answers to the Exercises - Chapter 9. The Power of the Command Line - 9.2. Searching and Extracting Data from Files - Exercise 9.2.12

Linux Essentials Version 1.6 Exam Study Resources: Linux Essentials Manual - Appendix A. Answers to the Exercises - Chapter 9. The Power of the Command Line - 9.3. Turning Commands into a Script - Exercise 9.3.12

The operator that matches the preceding character either zero or one time in a regular expression is the question mark (?). This operator is also known as the optional quantifier, because it makes the preceding character or group of characters optional. For example, the regular expression colou?r matches both color and colour, because the u is optional. The question mark can also be used to modify other quantifiers, such as * (zero or more), + (one or more), or {m,n} (between m and n times), to make them non-greedy, meaning they will match the shortest possible string instead of the longest. For example, the regular expression .*? matches any character zero or more times, but as few as possible. The question mark is one of the basic regular expression operators covered in the Linux Essentials certification program from the Linux Professional Institute (LPI). References:

Linux Essentials - Linux Professional Institute (LPI)

Regular Expressions:Difference between ‘optional occurrence’ and 'zero …

The grep command is used to search for a pattern in a file or input. The -i option makes the search case-insensitive, meaning that it will match both uppercase and lowercase letters. The grep command takes the pattern as the first argument and the file name as the second argument. Therefore, the command grep -i linux operating-systems.txt will find all lines in the file operating-systems.txt which contain the term linux, regardless of the case. References: Linux Essentials - Topic 103: Finding Linux Documentation and Linux Essentials - Topic 104: Command Line Basics

 The correct command to copy the contents of the directory /etc/, including all sub-directories, to /root/ is cp -r /etc/* /root. This command uses the cp command, which stands for copy, and is used to copy files and directories on Linux and Unix systems. The command also uses the following options and arguments123:

The -r option, which stands for recursive, and tells cp to copy all files and sub-directories of the source directory. Alternatively, the -R option can be used, which has the same effect as -r.

The /etc/* argument, which specifies the source directory and all its contents. The asterisk (*) is a wildcard character that matches any file or directory name. This argument tells cp to copy everything inside the /etc/ directory, but not the directory itself.

The /root argument, which specifies the destination directory. This argument tells cp to copy the source files and sub-directories to the /root/ directory.

The other options are incorrect because they use different commands or syntax that do not copy the contents of the directory /etc/, including all sub-directories, to /root/. For example:

Option A uses the copy command, which is not a valid Linux command. The correct command is cp.

Option C uses the -v option, which stands for verbose, and tells cp to print verbose output. This option does not affect the copying process, but only the output. It also does not include the -r or -R option, which is necessary to copy the sub-directories.

Option D uses the rcp command, which stands for remote copy, and is used to copy files between different hosts on a network. This command is not relevant for copying files on the same host.

Option E uses the -R option, which is correct, but also uses the . argument, which is incorrect. The dot (.) is a special character that matches any single character. This argument tells cp to copy only the files and directories that have a dot in their name, which may exclude some files and directories that do not have a dot.

References: 1: Cp Command in Linux (Copy Files) | Linuxize 2: cp command in Linux with examples - GeeksforGeeks 3: How to Copy Files and Directories in the Linux Terminal