RedHat RH033 - Red Hat Linux Essentials

The read permission allows a user to read a file. The content of a file can be seen by cat or less commands. When the read permission is set for a directory, it allows a user to read the names of files in the directory (but not to find out any other information about them including file type, ownership, size, etc.).

The write permission means that a user is permitted to write in a file. So, if a file has the write permission it can be edited and saved.

The execute permission grants a user the ability to execute a file. This permission must be set for executable binaries.

Answer option C is incorrect. If a file has the read permission, its contents can also be read not only the file name.

The lpq command views the content of a print queue.

Answer option D is incorrect. The lpr command sends a job to the queue to be printed.

Answer option A is incorrect. The lprm command removes a job from the queue.

Answer option B is incorrect. The lpstat -a command lists the configured printers.

The tail or tail -10 command can be used to see only the last ten lines of a file. The tail -n command is used to see the last n lines of a file. By default, the tail command shows the last 10 lines of a file.

Answer options A and C are incorrect. The head or head -10 command can be used to see only the first ten lines of a file. The head –n command is used to see the first n lines of a file. By default, the head command shows the first 10 lines of a file.

The less command is most useful for viewing large files. The less command displays the output of a file one page at a time. Viewing large files through cat may take more time to scroll pages, so it is better to use the less command to see the content of large files.

Answer option B is incorrect. The cat command is also used to view the content of a file, but it is most useful for viewing short files.

Answer option A is incorrect. The cp command is used to copy files and directories from one location to another.

Answer option D is incorrect. The touch command is not used to view the content of a file. It is used to create empty files or to update file timestamps.

The 3l command in vi will move the cursor 3 characters to the right when you are in command mode of vi editor. You can go into command mode by pressing the key.

What is the vi editor?

The vi editor is an interactive, cryptic, and screen-based text editor used to create and edit a file. It operates in either

Input mode or Command mode. In Input mode, the vi editor accepts a keystroke as text and displays it on the screen, whereas in Command mode, it interprets keystrokes as commands. As the vi editor is case sensitive, it interprets the same character or characters as different commands, depending upon whether the user enters a lowercase or uppercase character. When a user starts a new session with vi, he must put the editor in Input mode by pressing the "I" key. If he is not able to see the entered text on the vi editor's screen, it means that he has not put the editor in

Insert mode. The user must change the editor to Input mode before entering any text so that he can see the text he has entered.

Answer option D is incorrect. The 3h command will move the cursor 3 characters to the left.

Answer option B is incorrect. The 3w command will move the cursor forward by 3 words.

Answer option A is incorrect. The 3b command will move the cursor backward by 3 words.

The rm -rf commarecursively removes directories and its contents, ignoring warnings about removing write-protected files and directories.

Answer option B is incorrect. rm -f removes only files forcibly not a directory. To remove a directory and its contents forcibly, use -r in combination with -f with the rm command.

Answer option C is incorrect. The rmdir command is use to remove an empty directory.

Answer option D is incorrect. rm with no arguments deletes files.

This command will search for files with a size of over 50 megabytes. The -size option tells find to search files according to the size of files, and

+50M will tell the find command to search files over 50 megabytes.

Answer option C is incorrect. This command will search for files with a size of exactly 50 megabytes.

Answer option B is incorrect. This command will search for files with a size of less than 50 megabytes.

Answer option D is incorrect. - must be prefixed with size, otherwise shell will not recognize this command, and display an error message.

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.

You will use the lpstat -s command to accomplish the task. The lpstat -s command gives you information about what printers are configured on your computer and how you can connect to them.

Answer option A is incorrect. The lpstat -p command is used to list the printers configured on your computer.

Answer options C and D are incorrect. The lpstat -d and lpr commands are used to list the default printer on your computer.