RedHat RH033 Red Hat Linux Essentials Exam Practice Test

A pipe is a way to connect the output of one command to the input of another command without any temporary file.

What is a pipe?

A pipe is a temporary storage place where the output of one command is stored and then passed as the input for another command. Pipes are used to run more than two commands from the same command line.

Syntax:

command1 | command2 | command3...........etc.

Answer option A is incorrect. The operator > is used to redirect standard output (STDOUT) to a file.

Answer option C is incorrect. The operator 2> is used to redirect standard error (STDERR) to a file.

Answer option D is incorrect. The operator &> is used to redirect all output to a file.

xinit is a program that allows a user to manually start an X server. The startx script is a front-end for xinit. By default, xinit and

startx start an X server on display :0 and then start an xterm on it. When the xterm terminates, xinit and startx kill the X server. In general,

xinit and startx can start an arbitrary server and run an arbitrary script. Typically, this script runs a number of programs and a window manager. Arguments immediately following the startx command are used to start a client in the same manner as xinit. For example the startx -

- -dpi 100 command starts the xsession with 100 dpi.

The chmod command is used to change file access permissions in Linux.

Syntax: chmod [option] [mode]

Option: The following is a list of some important options that can be provided with the command:

Mode: Mode is written in the following format:

[ugoa] [+-=] [rwxXstugo]

The combination of ugoa specifies the users for whom the file access permissions will be changed. In

ugoa, u is for the user who owns the file,

g is for other users in the file group, o is for other users not in the file group, and a is for all users.

The operator + adds the specified permissions to the existing permissions of each file. The - operator

removes, and the = character specifies

that the specified permissions are the only permissions for that file.

The combination of rwxXstugo is permission type. In rwxXstugo, r is for read, w is for write, x is for

execute, X is to execute only if the file is a

directory or already has execute permission for some user, s is to set user or group ID on execution, t

is to save program text on swap device,

u are the permissions that the user who owns the file currently has for it, g are the permissions that

other users in the file group have for the

file, and o are the permissions that other users not in the file group have for the file.

Answer option A is incorrect. The chown command is used to change the user or group ownership of

the files specified with the command.

Answer option D is incorrect. The chgrp command is used to change only the group ownership of the

files specified with the command.

What is the chgrp command?

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 C is incorrect. There is no such command as chperm in Linux.

According to the question's requirement, the following time specifications can be set for the cron

job:

30 17 * * 5

30 17 * * FRI

In this time specification, you can define five parameters. The first two parameters define minutes and hours of the day. The last or the fifth parameter shows the day of the week. It can be the name or the number of a day. Numbers 0 and 7 are for Sunday, whereas from Monday to

Saturday, the numbers are from 1 to 6.

The fdisk command is a menu-based command available with Linux for hard disk configuration. This command can perform the following tasks:

Delete a partition on a hard disk.

Create a partition on a hard disk.

Change the partition type.

Display the partition table.

Note: The sfdisk command-line utility is an alternative to the fdisk command.

Answer option C is incorrect. In Linux, the mount command is used to mount and display disks, partitions, and file systems. Mounting refers to the process in which the operating system prepares the media to be read.

Anwer option D is incorrect. The File System Check (fsck) command is used to scan all disks and partitions, and it repairs them if required. The

fsck command should be run only on an unmounted file system.

Note: The function of the fsck command is similar to that of the Window's scandisk utility.

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

In order to know the name of the current shell, he will run the following command:

ECHO $shell

The command line interpreter in Linux is known as the shell. When a user runs a command, the shell interprets, processes, and executes the command and provides an output to the user. Linux comes with quite a few shells such as Bourne

Shell, Bourne Again Shell (BASH), C Shell, Korn Shell, etc. Bash is the most popular shell used by Linux users.

What is BASH?

The Bourne Again Shell (BASH) is a command language interpreter for the GNU's Not Unix (GNU) operating system. The following files are used to configure BASH:

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 ps2pdf utility is used to convert PostScript to a PDF file.

What is a ps2pdf command?

The ps2pdf command creates PDF files. It is used to convert a PostScript file to a PDF file.

There are a number of versions of this program, some are as follows:

Answer option D is incorrect. The enscript utility converts a text to a PostScript format and sends it to a file or the print queue.

Answer option B is incorrect. The evince utility is used to view a PDF file, not to create a PDF file.

What is the evince command?

The evince command is a document viewer capable of displaying multiple and single page document formats such as PDF and Postscript.

Syntax: evince [Options] [Filename]

In Linux, the directories are simply special files that have an inode and a data section.

The contents of the data section are a list of the directory's contents. In order to enter a directory or list its contents, a user must have the Read permission on the directory. The Write permission is required to modify that list.

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 second column in the listing shows the number of hard links created for the file.

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 most likely cause of the issue is that David does not have the Write permission on the Sales directory.

The listing of the directory shows that root is the owner of the Sales directory. The permissions on the Sales directory are rwxr-xr-x. The permission character set has three sets of three permissions that are Read, Write, and Execute. The first set, which is rwx, represents the

Read, Write, and Execute permissions to the owner of the file. The second set, which is r-x, provides the Read and Execute permissions to the group root. The third set, which is r-x, provides the Read and Execute permissions to other users.

In order to resolve the issue, you will have to make David the owner of the Sales directory. For this, you will have to run the following command:

chown david sales

After becoming the owner of the directory, David will automatically get the Write permission, and he will be able to store his files in the directory.

Setting permissions on files and folders in Linux

Answer option B is incorrect. As the listing shows that David is not the owner of the folder, this will not make any difference.

Answer options D and C are incorrect. According to the question, the directory is properly listed, and mounting or deletion is not an issue.

The date command with the %M specifier prints the current time (Minutes). Since the output is redirected towards the date.txt file, the current time (Minutes) will be printed in the date.txt file.

The useradd or adduser command is used to add a user on the Linux operating system.

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.

The ls ~ and echo * commands can be used by a user to display the list of contents existing in his current user account. While ~ forces a command to perform queries in the user's home directory, ls displays the contents of the home directory.

If the package is not yet installed, the yum deplist httpd command is used to get the list of packages that httpd depends on.Answer option C is incorrect. The yum list httpd command can be used to list various information about available packages. For example, it lists all available and installed packages and all packages with updates available in the yum repositories.

Answer option D is incorrect. If the package is already installed, the rpm -qR httpd command is used to get the list of packages that this package depends on.

Answer option A is incorrect. This command is incorrect. The deplist option is not used with the rpm command.

You can use the file command to display the file types of all the files in a directory at a time. In order to accomplish the task, you will have to issue the following command:

file *

What is the file command?

The file command is used to analyze the files specified in the argument.

Syntax:

file [] [] ...

By providing the name of a file as an argument, the file command analyzes the file. The file command supports multiple arguments. The asterix (*) metacharacter can also be used with the file command.

Answer option C is incorrect. In Linux, the mount command is used to mount and display disks, partitions, and file systems. Mounting refers to the process in which the operating system prepares the media to be read.

Answer option A is incorrect. The File System Check (fsck) command is used to scan all disks and partitions, and it repairs them if required. The fsck command should be run only on an unmounted file system.

Answer option D is incorrect. The init command is used to switch a Linux computer to different run levels.

Pidgin (formerly named Gaim) is a multi-platform instant messaging client, based on a library named

libpurple. Libpurple has support for many commonly used instant messaging protocols, allowing a user to log into various different services from one application.

What is Pidgin?

Pidgin is a multi-protocol Instant Messaging client that allows a user to use all of his IM accounts at once. It is a free software that can work with AIM ,Gadu-Gadu, Jabber, ICQ ,IRC, MSN, SILC, XMPP, Yahoo!, and Zephyr Network. Anyone is free to use it and modify it, but if a user distributes his modifications, he must distribute the modified source code as well.

The license of this communication software is Freeware, i.e. anyone can freely download and use this communication software.

Answer options A and D are incorrect. Evolution and Thunderbird are Graphical mail clients in Linux.

It is not an Instant Messenger.

What is Evolution?

Evolution is a full-featured personal and workgroup information management tool for Linux systems, and is the default email client for Red Hat Enterprise Linux. It provides all of the standard email client features, including powerful mailbox management, user-defined filters, and quick searches. Its additional feature is a flexible calendar/scheduler, which allows users to create and confirm group meetings and special events online.

What is Thunderbird?

Mozilla Thunderbird is a free, open source, cross-platform e-mail and news client developed by the

Mozilla Foundation.

Thunderbird can manage multiple e-mail, newsgroup and RSS accounts and supports multiple identities within accounts.

Thunderbird incorporates a Bayesian spam filter, a white list based on the included address book, and can also understand classifications by server-based filters such as SpamAssassin. Thunderbird provides enterprise and government-grade security features such as SSL/TLS connections to IMAP and SMTP servers. It also offers native

support for S/MIME secure email (digital signing and message encryption using certificates).

Answer option B is incorrect. mutt is an email client that manages emails within a text-only environment. It is not an Instant Messenger.

What is mutt? mutt is a powerful tool for managing email within a text-only environment. This tool is very important to access email even when a graphical interface is not available. Some of its strengths are handling of message threads and flexibility. When mutt sees a series of related messages, it displays each reply under the parent. mutt supports sending of attachments through a mail. The following example describes how a file can be attached to a mail: echo "Sending an attachment." | mutt -a backup.zip -s "attachment" local@domain.com

This command will send a mail to local@domain.com with the subject (-s) "attachment", the body text "Sending an

attachment.", containing the attachment (-a) backup.zip.

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.

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.