RedHat RH033 Red Hat Linux Essentials Exam Practice Test

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 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.

The head -n 5 /etc/passwd command will show the first 5 lines of the file /etc/passwd.

The ps command reports the status of processes that are currently running on a Linux computer.

What is > command?

The > command is used for storing the output generated by different commands. It creates a file specified to store the output. If the specified file already exists, it overwrites that file.

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.

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.

SELinux is an operating system based on Linux which includes Mandatory Access Control. The

SELinux provides Kernel-level security for Red Hat Enterprise Linux.

Answer options C, B, and A are incorrect. These are the features of SELinux.

What are the features of SELinux?

The features of SELinux are as follows:

SELinux provides Kernal-level security.

SELinux implements Mandatory access control (MAC) security in Red Hat Enterprise Linux.

SELinux assigns every file and process on the system a context, identifying its type and purpose.

SELinux enforces a policy that dictates which actions a given type of process may take on a given type of file

SELinux applies to all users, including root.

The lpc command is used to check the status of printers, enable and disable printers, and change the arrangement of jobs in the 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 lpq command views the contents of the print queue.

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

The ifdown command is used to set down the interface and flush all its addresses. It is possible to let

ifdown check the interface if the interface is still used before setting it down. If the interface is used it may then discard the using processes or refuse setting it down.

To enable this feature, check /etc/sysconfig/network/config file.

Answer option A is incorrect. The ifup command is used to bring up a preconfigured interface for networking. It is usually invoked by the network script at boot time or by the PCMCIA/hotplug system. It can also be used to start interfaces manually on the command line. It activates the link, adds addresses and other parameters and sets up the routes for an interface.

Answer option C is incorrect. The ifconfig commands displays the basic settings of a network device.

Answer option D is incorrect. There is no such command as down.

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.

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.

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.

The manual section 8 of MAN pages provides help information for administrative commands.

Manpages are grouped into sections. Sometimes a user has to know the appropriate section in which he wants to search for an item. For example, if a user is interested in the print Clanguage function rather than the command, he has to tell the man program to search the section on library functions. The user can enter the following command to search the c-language print function: man 3 print

The various MAN sections are as follows:

If no path is given, find looks in the current directory and its subdirectories. Using the -i option tells the find command to perform caseinsensitive search for files named snow.html. It will show all files named snow.html, Snow.html,

SNOW.html in the current directory.

Answer option B is incorrect. This command will only search for files named snow.html in the current directory with case-sensitiveness. It will not search for those files named Snow.html, SNOW.html.

Answer option C is incorrect. This is an incorrect command; it will show an error message.

Answer option D is incorrect. This is also an incorrect command, there should be a name after -i in the command.

The locate command queries a database for all pathnames which match the specified pattern. The –n option followed by an integer limits the results to a specific number. This command would display only 10 results in a search for files that have an .html extension.

What is the locate command?

The locate command queries a database for all pathnames which match the specified pattern. The database is updated periodically (usually weekly or daily), and contains the pathnames of all files which are publicly accessible.

Syntax for the locate command is as follows: locate [options] pattern ...

Here, pattern means one or more file patterns.

The following options are used with the locate command:

Answer option A is incorrect. This command uses the star wildcard to display all files on the system that have the .html filename extension.

Answer option D is incorrect. The -q option is used to suppress error messages, such as those that might be returned in the event that the user does not have permission to access designated files or directories. Thus, this command would suppress any error messages regarding tothis search.

Answer option B is incorrect. When this command is run on the terminal an error message will be displayed on the screen.

The lpstat -a, lpstat -l commands list the configured printer in the network.

Answer option D is incorrect. The lpstat -r command shows whether or not the CUPS server is running. Answer option C is incorrect. The lpstat -o command shows the jobs queue on the specified destinations.

The jobs command lists the jobs that are running in the background and in the foreground. If the prompt is returned with no information, no jobs are present.

Syntax:

jobs [-p | -l] [-n] [-p] [-x] [job id]

Some important options used with jobs command are as follows:

Answer option A is incorrect. The top command is used to produce a frequently-updated list of processes. By default, the processes are ordered by percentage of CPU usage, with only the "top" CPU consumers shown. This command shows how much processing power and memory are being used, as well as other information about the running processes. The following figure demonstrates the output of the top command:

Answer option B is incorrect. The bg command can be used to resume in the background when a process is suspended.

Answer option C is incorrect. There is no such command as job.

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 lprm - and lprm -a all commands can be used to delete all jobs queued in a printer. 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,

Answer options B and C are incorrect. These are not valid lprm command syntaxes.

The cp -u command copies only when the source file is newer than the destination file or when the destination file is missing.

Answer option C is incorrect. The cp -p command copies the files from source to destination with preserving file attributes, such as timestamps, mode, and ownership.

Answer option B is incorrect. The cp -l command links files from source to destination instead of copying.

Answer option D is incorrect. The cp -s command makes symbolic links instead of copying.

The usermod -d -m command is used to change the home directory of a user as well as move all of its contents to the new home directory.

The following directories cannot be separated from the root filesystem:

/lib

/dev

/etc

/sbin

/bin

Answer option D is incorrect. /var can be separated from the root filesystem. Such filesystems are known as optional filesystems. Some of the optional filesystems are as follows:

/var

/usr

/opt

/home