Effective Study Techniques for the RedHat RH033 Exam

In order to replace all the occurrences of "net" with "Net" in the first fifty lines of the file, you will have to execute the following command: :1,50 s/net/Net/g

This command is issued in the command mode of the VI utility. 1,50 defines the initial and final line numbers of the current document where the command will execute. The s/ switch with the net/Net/g option will globally replace all the occurrences of "net" with "Net".

Answer option A is incorrect. This command will replace "net" with "Net" all over the current document.

Answer option B is incorrect. Since this command executes on the first 100 lines of a document, it will replace "net" with "Net" in all the 100 lines of the current document.

Answer option D is incorrect. This command will replace "net" with "Net" in the current line of the current document.

This is the correct syntax for granting ownership of foofile to John.

What is the chown command?

The chown command is used to change the ownership of a file. Only root can change the ownership of a file. The chown command can be used with the -R option to recursively change the ownership of an entire directory tree.

Syntax:

chown [-R] newowner filename

Answer option B is incorrect. The chmod command is used to change access mode for files and directories.

Answer option D is incorrect. The syntax of this command is not correct. With chown, first write the name of the user whom you want to give ownership, then write the filename of the file whose ownership you want to change.

Answer option C is incorrect. The chgrp command is used to change Group-ownership not file ownership.

The lprm command is used to remove the print jobs that have been queued for printing. If no arguments are supplied, the current job on the default destination is cancelled. The command syntax for the lprm command is as follows:

lprm [-E] [-U username] [-h server[:port]] [-P destination[/instance]] [-] [job ID(s)]

where,

When 1 is added as a prefix to the permission set, it adds the sticky bit to the file permission.

Therefore, in order to accomplish the task, you will have to run the following command: chmod 1744 report

What is sticky bit?

The sticky bit is a part of a permission set applied to files or folders. The sticky bit prevents others from deleting files from a folder. When the sticky bit is set on a directory, only the owner or root can unlink (delete) or rename the files in that directory. Without the sticky bit, anyone who is able to write to the directory can delete or rename the files.

Answer option A is incorrect. This will set SGID to the file permission.

Answer option B is incorrect. This will set SUID to the file permission.

Answer option C is incorrect. Although this will add a sticky bit to the file permission, it will also set SGID and SUID to the file permission.

What are SUID and SGID?

Set user ID (SUID) and Set group ID (SGID) are used to set a file to run as something other than the standard. Normally, when a file is executed, it runs as the user who invokes it. Setting a file to SUID or SGID simply requires adding an extra digit to the permissions. Technically, if no digit is used, it assumes a leading 0.

According to the scenario, John will use the chgrp bar foo command to accomplish the task. The chgrp (from change group) command is used by unprivileged users to change the group associated with a file. Unlike the chown command, chgrp allows regular users to change groups, but only to one of which they are a member. The general syntax of the chgrp command is as follows:

chgrp group target1 [target2 ..]

The group parameter indicates the new group with which the targets should be associated.

The target1 parameter indicates the files or directories for which the change should be made.

The target2 parameter indicates the optional additional files or directories for which the change should be made.

For example:

The above command changes the group associated with ttt to 'system', provided the executing user is a member of that group.

Answer option A is incorrect. In the chgrp command, first we write the group name and after that, we write the file name. But here just the opposite is written, so this command will not give the desired result.

Answer options D and B are incorrect. There is no such command as chgroup in Linux.

The Interface configuration files are read by system-config-network, ifup, ifdown, and other tools that bring network interfaces up and down.

Answer option B is incorrect. The system-config-services tool is used to manage services in Linux.

The zip -r foobar.zip filesdir command is used to create a file named foobar.zip and put it into the directory named filesdir. foobar.zip represents the file you are creating and filesdir represents the directory you want to put in the new zip file. The -r option specifies that you want to include all files contained in the filesdir directory recursively.

Answer option A is incorrect. The unzip foobar.zip command is used to extract the contents of a zip file to the filesdir directory.

Answer option D is incorrect. The gunzip foobar.zip command is used to expand the compressed file.

Answer option C is incorrect. The tar -tvf foobar.tar command is used to list the contents of a tar file.

This command will run sort on the file marketing.txt and sort the file in the reverse alphabetical order.

Answer option B is incorrect. sort with no options is used to sort file alphabetically. It will not sort the file in the reverse alphabetical order.

Answer option C is incorrect. The -n option used with the sort command sorts the text numerically, instead of by characters.

Answer option A is incorrect. The -u option with sort removes duplicate lines from the output.

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 pwd command-line utility is used to display the current working directory.

What is the pwd command?

The pwd command prints the complete pathname of the current working directory to the standard output.

pwd [ -L | -P]

The options are described as follows:

OptionDescription

-LDisplays the logical current working directory.

-PDisplays the physical current working directory.

If no options are specified, the -L option is assumed.

Answer option A is incorrect. The ls command lists the contents of the current directory or the specified directory.

Answer option D is incorrect. The cd command with no argument is used to move to your home directory.

Answer option C is incorrect. The mv command is used to move and/or rename files and directories.