RedHat RH033 Red Hat Linux Essentials Exam Practice Test

The yum remove packagename and yum erase packagename commands are used to remove a specified package from a Linux system. If any packages depend on this package, yum will prompt about this and give the option to remove those packages too.

Answer options A and C are incorrect. These commands are incorrect. The -r and -rm options are not used with the yum command to remove a package from a Linux system.

The lpc command can be used to rearrange jobs awaiting printing, as well as to disable/enable a

printer or queue and find the status of printers.

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

Answer option A is incorrect. The lpq views the contents of the queue.

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

According to the scenario, since John wants to copy all files with the .dat extension from /home/john

to /home/maria while preserving the file

attributes such as timestamps, mode, and ownership, he will use the cp -p /home/john/*.dat

/home/maria command to accomplish the task. The cp -p command copies files from source to destination while preserving the file attributes, such as timestamps, mode, and ownership.

Answer option B is incorrect. The cp -R /home/john/*.dat /home/maria command will recursively copy all .dat files from source to destination; however, it will not preserve the file attributes.

Answer option D is incorrect. The cp -l /home/john/*.dat /home/maria command will link all .dat

files from /home/john to /home/maria instead of copying them.

Answer option C is incorrect. The cp -l /home/maria/*.dat /home/john command will link all .dat

files from /home/maria to /home/john instead of copying them.

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.

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.

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.

In order to run the script, you are required to add the execute permission to the script file. The permission can be assigned through the chmod command.

What is the chmod command?

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.

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.

According to the scenario, John wants to change the modified date and time of the file private.txt to a desired date and time. For this, he can use either the touch -t or touch -d command. The difference between these two commands is that the touch -d command is more flexible, while the touch -t command takes the date and time in the format MMDDhhmm.ss.

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 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 cat command concatenates both files foo.txt and student.txt together and | (pipe) will send the standard output of the cat command to the standard input of the less command, and this will show the output of both files on one screen at a time.

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.

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:

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.

The $! environmental variable represents the PID value of the last child process.

Answer option D is incorrect. The $$ environmental variable represents the PID of the running shell.

Answer option A is incorrect. The $? environmental variable results in the value zero if the last command was executed successfully, otherwise it displays the value one.

Answer option C is incorrect. It is an invalid Linux standard environmental variable.

You will use find -name foobar.png command to do case-senstive search for files named foobar.png.

What is the find command?

The find command can perform a search based on a variety of search limitations. It searches through one or more directory tree(s) of a filesystem, locating files based on some user-specified criteria. By default, find returns all files in the current working directory. Further, find allows a user to specify an action to be taken on each matched file.

Thus, it is an extremely powerful command for applying actions to many files.

The find command can be used with a wild card (*), but it works best when we know the name of the file or directory we are looking for.

The find command can search your system for files that comply with certain numeric criteria, such as the size of the file (-size), the number of links to the file (-links), the date of the last change to the files data (-mtime), or the date of the last time the file was read (-atime). All these criteria accept a numeric value. When a numeric value is provided to find, it looks for an exact match, more than the number, or less than the number.

Answer option B is incorrect. The find -iname foobar.png command will do case-insensitive search for files named foobar.png.

Answer option C is incorrect. The grep-name foobar.png is an invalid command.

What is the grep command?

The grep command is used to search for a specific pattern of text in a file. It helps administrators in searching large amounts of text for a certain error message or name.

Answer option A is incorrect. The locate -name foobar.png is an invalid command.

What is the locate command?

The locate command is used to search for matching files in a database that is usually updated daily by a cron job. On the forthcoming Linux operating systems, this command is usually replaced by the slocate command, which stores permissions as well as paths and thus prevents users from prying into directories. One more advantage of the locate command is that it matches against any part of a pathname, not just the file itself.

This command will prompt you to remove Joe's tmp files that are 3 days older. When the -ok option is used with the find command it causes find to execute the rm command once for each /tmp file that is 3 days older. {} can be used as a filename placeholder.

The -ok option with the find command is used to execute a command once for each file that matches the given criteria. This is commonly used in situations such as removing files or renaming files to have a certain extension. The -ok option causes find to ask for each file before removing it.

What is the find command?

The find command is a versatile method for locating files on a file system. The syntax for this command is as follows:

find -

Some of the important criteria are described in the table below:

What are some numeric criteria that the find command uses?

The find command can search your system for files that comply with certain numeric criteria. For

example, -ctime, -atime, -

cmin, -amin, etc. The -ctime and -atime are measured in days and the -cmin and -amin are measures in minutes.

For example:

find /tmp -ctime +10

This command searches for files that are more than 10 days older.

find /tmp -cmin +10

This command searches for files that are more than 10 minutes older.

What is the purpose of using \; at the end of the find command?

The purpose of using \; at the end of the find command is that when find is used with -exec and –ok the find command uses ; as the delimiting character. Unfortunately ; is also a delimiting character for the bash shell so we must prevent bash from interpreting it. When a character is preceded with a backslash (\), bash instructs it literally, so typing \; at the bash command prompt will send ; to find command after bash has done its interpretation.

Answer option A is incorrect. This command will prompt you to remove Joe's tmp files that are 3 minutes older.

Answer options D and B are incorrect. These are the incorrect command syntaxes.

You can view all running processes with the help of the ps -aux command. Hence, any of the ps –aux commands (i.e., ps -aux | grep cc, ps -aux

| more, or ps -aux) can be used to check whether the cc process is running on the computer.

Answer option B is incorrect. The tail command is used to display the last few lines of a text file or piped data. It has a special command line option -f (follow) that allows a file to be monitored. Instead of displaying the last few lines and exiting, tail displays the lines and then monitors the file. As new lines are added to the file by another process, tail updates the display. This is particularly useful for monitoring log files. The following command will display the last 10 lines of messages and append new lines to the display as new lines are added to messages: tail -f /var/adm/messages

The default tool for email and groupware in Red Hat Enterprise Linux is called Evolution. Evolution provides not only the email access, but also the ability to maintain a calendar, tasklist and contacts database.

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.

Answer option C is incorrect. Thunderbird is a graphical mail client that offers email, Usenet and rss support but it does not support groupware features. Thunderbird is provided along with Firefox and others as part of the Mozilla suit of application.

What is groupware?

Groupware refers to programs that help users work together collectively while located remotely from each other.

Groupware services can include the sharing of calendars, collective writing, e-mail handling, shared database access, electronic meetings with each user able to see and display information to others, and other activities. Sometimes called collaborative software, groupware is an integral component of a field of study known as Computer-

Supported Cooperative Work or CSCW.

Answer options A and D are incorrect. The mutt and pidgin are Non-GUI mail clients.

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.

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.

Open source software is software that has been released under an Open Source Initiative (OSI) certified license. The definition includes 10 criteria, which are described as follows:

Open source software is software that has been released under an Open Source Initiative (OSI) certified license. The definition includes 10 criteria, which are described as follows:

1. Free Redistribution: The license allows any party selling or giving away the software as a component of an aggregate software distribution comprising programs from many different sources.

2. Source code: Anyone can modify the source code.

3. Derived Works: The license must allow changes and derived work under the same conditions as the license of the original software.

4. Integrity of the authors source code: To maintain the integrity of the original authors work, the license may require that changes to the code be provided in patch form.

5. No Discrimination Against Persons or Groups: The license must be nondiscriminatory with respect to persons or group of persons.

Therefore, open source license are forbidden from locking anyone out of the process.

6. No Discrimination Against Fields of Endeavor: The license must not restrict anyone from making use of the software in a specific field of endeavor.

7. Distribution of License: The license can be distributed to all but the rights attached to that program must apply to all to whom the program is distributed. And no party can execute any additional license.

8. License Must Not Be Specific to a Product: It may not require that the software be part of particular distribution.

9. License Must Not Restrict Other Software: It may not restrict other non-open source software.

10. License Must Be Technology-Neutral: It may not require the use of technology to apply the license.

Answer options B and A are incorrect. These are the characteristics of closed source software.

find /etc -name *.txt command is used to search for files anywhere on the system that end in .txt.

What is the find command?

The find command can perform a search based on a variety of search limitations. It searches through one or more directory tree(s) of a filesystem, locating files based on some user-specified criteria. By default, find returns all files in the current working directory. Further, find allows a user to specify an action to be taken on each matched file.

Thus, it is an extremely powerful command for applying actions to many files.

The find command can be used with a wild card (*), but it works best when we know the name of the file or directory we are looking for.

The find command can search your system for files that comply with certain numeric criteria, such as the size of the file (- size), the number of links to the file (-links), the date of the last change to the files data (-mtime), or the date of the last time the file was read (-atime). All these criteria accept a numeric value. When a numeric value is provided to find, it looks for an exact match, more than the number, or less than the number.

Answer options D, B, and C are incorrect. There is no such commands in the Linux.