RH033 Exam Dumps - Red Hat Linux Essentials

smbclient is a command-line tool that provides access to SMB/CIFS shares.

What is the smbclient command?

smbclient is a command-line tool that provides access to SMB/CIFS shares. smbclient is a samba client with an "ftp like" interface. It is a useful tool to test connectivity to a Windows share. It can be used to transfer files, or to look at share names. In addition, it has the ability to backup and restore files from a server to a client and visa versa.

Example:

#smbclient -L server1

The above command will list all shares on server1.

Some useful options are as follows:

Answer option C is incorrect. scp copies files between hosts on the Linux network.

Answer option A is incorrect. rsync is a fast and extraordinarily versatile file copying tool. It can copy locally, to/from another host over any remote shell or to/from a remote rsync daemon.

What is rsync?

In computing, rsync is a software application for Unix systems. It synchronizes files and directories from one location to another while minimizing data transfer using delta encoding. It can copy or display directory contents and copy files, optionally using compression and recursion.

In daemon mode, rsync listens to the default TCP port of 873, serving files in the native rsync protocol or via a remote shell such as RSH or SSH. In the latter case, the rsync client executable must be installed on both the local and remote hosts.

Answer option B is incorrect. mutt is a small but very powerful text based program for reading electronic mail under Linux operating systems.

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

In order to accomplish the task, you will have to kill the process and rerun it by using the nice command to lower the priority of the process.

You will have to run the following command: kill : nice -n 19

The nice command is used to run a process with the desired priority level. The priority level varies from 1 to 19. Level 1 is for the highest priority and level 19 is for the lowest. By default, every process runs with the priority level 10.

Answer option C is incorrect. The fg command is used to run a process in the foreground.

Answer option D is incorrect. The bg command is used to run a process in the background.

Answer option A is incorrect. The -n 1 switch will provide the process the top priority.

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.

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.

The cmd1 2>&1 | cmd2 command pipes stdout and stderr from cmd1 to cmd2.

Answer option C is incorrect. The cmd1 | cmd2 command pipes stdout from cmd1 to cmd2.

Answer option B is incorrect. The cmd2 2>&1 | cmd1 command pipes the stdout and stderr from cmd2 to cmd1.

Answer option A is incorrect. The cmd2 | cmd1 command pipes stdout from cmd2 to cmd1.

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 cat data.txt.* command will display both the splitted files, and the > command will redirect the output into a new data.txt file.

What is the cat command?

The concatenate (cat) command is used to display or print the contents of a file.

Syntax: cat filename

For example, the following command will display the contents of the /var/log/dmesg file: cat /var/log/dmesg

Note: The more command is used in conjunction with the cat command to prevent scrolling of the screen while displaying the contents of a file.

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.

Answer option A is incorrect. This command will open a new file data.txt.* into the vi editor.

Answer option D is incorrect. This command will give the vi editor a warning "output is not to a terminal" since the vi terminal cannot be redirected into the data.txt file.

Answer option B is incorrect. The less command displays only the first file data.txt.aa, and the > command redirects the output into the data.txt file. Hence, John will not get the desired output using this command.

The /etc/group file contains group information. This file shows which users are members of which groups.

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]

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 -c option with the wc command is used to count the number of bytes in a file. It shows only the number of bytes used by a file.

Answer option A is incorrect. The -l option with the wc command is used to count the number of lines in a file. It shows only the number of lines in a file.

Answer option D is incorrect. The -w option with the wc command is used to count the number of words in a file. It shows only the number of words in a file.

Answer option C is incorrect. The -m option with the wc command is used to count the number of characters in a file.

The evince utility is used to view PDF files on the Linux operating system.

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]

Answer options B and D are incorrect. These commands are used to convert a text to PostScript and send it to a file or the print queue.

What is PostScript?

PostScript is a language developed by Adobe Systems for printing documents on laser printers. It can also be adapted to produce images on other types of devices. It is the standard for desktop publishing. Every PostScript printer contains a built-in interpreter that executes PostScript instructions. Level 1, Level 2, and PostScript 3 are three basic versions of PostScript language.

Answer option A is incorrect. The ps2pdf utility is used to create PDF files.

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:

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 appends that file.

Answer option A is incorrect. 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.

Answer options C and B are incorrect. Improper syntax has been followed in these answer options.

Kernel files do not change regularly and therefore are contained in the /boot directory, not in the

/var directory.

What is the /var directory?

According to the Filesystem Hierarchy Standard, the /var directory contains regularly-changing system files. This comprises spool directories and files, and administrative and logging data.

Answer option A is incorrect. System log files are stored in the /var directory.

Answer options D and C are incorrect. Print spool files and email-spools are variable data files and therefore are contained in the /var directory.

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 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 shutdown -h now, halt -h, and poweroff -h commands can be used to shut down the Red Hat operating system immediately.

Answer option B is incorrect. This is an invalid answer and hence cannot be used to shut down the system.