The VI is a visual interactive text editor that allows a user to create, modify, and store files on a Linux computer. It works in the following modes:

Command: This is the default mode of the command. Various commands can be used in this mode to manipulate the opened text.

Input: In this mode, a user can insert text directly in the text screen area.

Answer option D is incorrect. The GNU zip (GZIP) utility is a compression utility that is used to compress files for saving space. It creates files with the .gz extension. It can also compress tar files. In order to unzip files with the .gz extension, the

GUNZIP command is used.

Answer option B is incorrect. The nmap utility, also commonly known as port scanner, is used to view the open ports on a Linux computer. It is used by administrators to determine which services are available for external users. This utility helps administrators in deciding whether to disable the services that are not being used in order to minimize any security risk.

Answer option C is incorrect. MS Word is a Windows-based utility. Hence, it cannot be used in Linux.

The history !! command shows the previously entered command in the bash shell. In the bash shell, the history command is used to view the recently executed commands. History is on by default. A user can turn off history using the command set +o history and turn it on using set –o history. An environment variable HISTSIZE is used to inform bash about how many history lines should be kept. The following commands are frequently used to view and manipulate history:

Answer option A is incorrect. The history !# command shows the entire command line typed.

Answer option D is incorrect. The history !n command shows the nth command typed. Since n is equal to 1 in this command, the first command will be shown.

Answer option C is incorrect. It is not a valid command.

The ls -al /root command lists all the files and directories, including hidden files in the /root

directory, in long listing format. /root is the root

user ' s home directory.

What is the ls command?

The ls command is used to list files on a Linux computer. The syntax of the ls command is as follows:

ls [option] [directory name]

Several options are used with the ls command. Following is a list of some important options:

For example, the following command displays all the files (including hidden files) in the /home

directory and the contents in

the subdirectories:

ls -aR /home

Answer option B is incorrect. The ls command without arguments lists the file and directory names

in the current directory.

Answer option C is incorrect. The ls -s /root command shows the size of all files and directories (in blocks, not bytes) that reside in the /root directory.

Answer option D is incorrect. The ls -h /root command shows the size of files and directories in

" human readable format " (i.e. 19M, 3G, etc).

Answer option C is incorrect. The pdf2ps utility is used to convert a PDF file to a PostScript.

You can use the tr command to convert all lowercase letters of a text file to uppercase. The tr

command is used to translate, squeeze, and/or delete characters from standard input, writing to standard output. If you want to change all lowercase letters to uppercase, you will use the tr

[a-z] [A-Z] command.

Answer options B, A, and D are incorrect. The cat, tac, and less commands are used to display the output of the text file on the screen. These commands cannot translate the text from one form to another.

The LPRM command is used to remove a file from a print queue.

Answer option D is incorrect. The LPQ command reports the status of a print queue.

Answer option A is incorrect. The LPR command is used to submit a file for printing.

Answer option B is incorrect. There is no command such as LPQDEL in Linux.

The tar -u command is used to append a tar file if the on-disk version of the tar file has a modification date more recent than its copy in the tar archive.

Answer option B is incorrect. The tar -t command is used to list the contents of an archive.

Answer option A is incorrect. The tar -x command is used to extract the files from an archive.

Answer option D is incorrect. The tar -c command is used to create a new archive of specified files.

The ipconfig network diagnostic tool is used in the Windows operating system to see IP addresses and MAC addresses, and other related information. It is not used in the Linux operating system. In the place of the ipconfig utility, ifconfig is used in Linux for performing the same task.

Answer option D is incorrect. The ping utility is a network diagnostic tool that checks TCP/IP connectivity on any host. It is used in both Linux and Windows operating systems.

What is the ping utility?

The ping command-line utility is used to test connectivity with a host on a TCP/IP-based network.

This is achieved by sending out a series of packets to a specified destination host. On receiving the packets, the destination host responds with a series of replies. These replies can be used to determine whether or not the network is working properly.

Answer option A is incorrect. This is a network diagnostic tool in Linux that perform hostname to IP address translation and vice versa.

Answer option B is incorrect. This is a network diagnostic tool in Linux which is used to perform hostname to IP address translations, and vice versa in greater detail.

You will use the ssh command to remotely login to the host York and then remotely execute the command ' df -h ' to check the disk space usage on the remote system.

creates a command prompt at bottom-left of screen. w will save the file and q will quit from the file. When :wq is used in combination and then the Enter key is pressed, this will save the file and exit it.

Answer option D is incorrect. : enters EX mode. EX mode will open a prompt on the last line of the terminal, and will accept certain keys for commands.

Answer option A is incorrect. :w only saves a file on the disk. To quit from the file after saving its contents, use q after :w.

Answer option C is incorrect. This key is used to quit from the file without saving its contents.

The mput command is used to upload multiple files simultaneously.

Answer option C is incorrect. The put command uploads one file each time you use the command. It is not used to upload multiple files at a time.

Answer option D is incorrect. The get command is used to download one file at a time.

Answer option B is incorrect. The mget command is used to download multiple files at a time. It is not used to upload multiple files.