/
to every directory name, so therefore it is the best choice. The mkdir -v
command creates a directory and lets you know whether or not it was successful, but it does not indicate directories, so option A is a wrong answer. The ls
command only displays file and directory names, so option B is also a wrong answer. The ls -i
command will display filenames along with their inode number, but it does not indicate directories, so option D is incorrect. While option E will work on some distributions to produce a long listing that can indicate directories, this command is not aliased to ls -l
on every distribution, so therefore it is not the best command to use.-d
switch on the ls
command will allow you to view a directory file's metadata instead of seeing metadata for the files managed by that directory. Therefore, option B is the correct choice. Option A is a wrong answer because the -a
switch forces the ls
command to display hidden files, which are files starting with a dot (.
). The -F
switch will append an indicator code to each file but not allow you to view a directory's metadata, so option C is a wrong choice. The -l
option is already being employed because you are viewing metadata, so it does not need to be added. Therefore, option D is an incorrect answer. The -R
switch allows you to view file information recursively through a directory tree, and thus option E is also a wrong choice.mkdir -v
command creates a directory and lets you know whether or not it was successful, so option A is the correct answer. The touch
command creates blank and empty files, so option B is incorrect. The cp -R
command will recursively copy an entire directory full of files to another directory. Since you do not know if the directory TheDir
is empty or not, you most likely did not use this command, so option C is a wrong answer. The mv -r
command will rename a directory to a new directory name. Again, you do not know if the directory TheDir
is empty or not, so you most likely did not use this command, and thus, option D is also a wrong answer. Option E is an incorrect answer because the rmdir
command deletes empty directories.rsync
utility allows you to perform fast local copies, so for a big file it is the best utility to use in this case. Therefore, option E is the correct answer. The readlink -f
command finds the file being pointed to via a series of soft links, so option A is an incorrect answer. The mv
command will rename a file instead of creating a backup copy, so option B is incorrect. The cp
command does create a file copy. However, it is not as fast as the rsync
utility and therefore is not the best choice, making option C a wrong answer. The scp
command also creates a file copy; however, it also is not as fast as the rsync
utility and therefore is not the best choice, making option D a wrong answer.rm -rI
command will recursively delete the files in the /home/Zoe
directory tree, and it will ask before it starts, so you know you are deleting the correct tree. Therefore, option E is the best answer. Option A is incorrect because the cp
command simply copies files; it does not remove them. Option B is incorrect because not only is part of the directory name using the wrong case, but there is no verification the correct directory is being moved to the black hole device, /dev/null/
. The rm -Rf
command would work, but it is not the best command to use because it does not ask before it starts, so you do not know if you are deleting the correct tree. In fact, the -f
option suppresses error messages, so option C is wrong. Option D would also work, but it is not the best answer because it employs the -i
option. If Zoe has years of files in her home directory, you may be sitting there for a long time deleting files due to the fact that you must confirm each file before it is deleted. Therefore, option D is an incorrect answer.mv
command. However, it is wise to use the -i
option, so if the new directory name already exists, the utility will stop and ask permission prior to proceeding. Even better is to use the -n
option; that way, if the new name you select is already being used, the mv
command does not allow you to overwrite it. Also, the -v
option is worthwhile, so the mv
command operates in verbose mode, telling you what is going on. Therefore, options B, C, and E are all correct choices. The -f
option is not a wise choice because it forces the directory's renaming, even if a directory already exists that has that name. Therefore, option A is a wrong answer. Also, there is no -r
switch, because renaming a directory using the mv
command does not require any recursive action. Thus, option D is an incorrect choice.cat -v
command will show any nonprinting characters that may have gotten embedded in the control file causing it to be corrupted, and therefore option A is the correct answer. The -z
option only lets you see end-of-line characters if they are NULL, and thus, option B is a wrong choice. The -n
option only numbers the text lines in output, so option C is also a wrong answer. The cat -s
command will display multiple blank lines in the file as one blank line. This will not help in the investigation, so option D is an incorrect answer. The -E
option displays a $
whenever a newline linefeed is encountered, and while possibly helpful, it is not the best option to use in this case. Therefore, option E is a wrong answer.pr -mtl 20
command. This will display the files side by side, remove any file headers or trailers, and set the page length to 20 lines so the files do not scroll off your screen. Of course, you may need to adjust the line length depending on your screen's resolution. Option A is incorrect because, while it will display the files side by side, the display may scroll off your screen. Option B is also incorrect, because the command will not display your files side by side. Option C is a wrong answer choice because the cat
command will not display the files side by side. Option E's command may work for you, but it is not the best choice because file headers or trailers will not be removed. Therefore, option E is an incorrect answer.head
command can use either the -n 15
switch or the -15
switch to display a file's first 15 lines. Therefore, option C is the correct answer. To display all but the last 15 lines of the file, you would need to employ the -n -15
switch, so option A is incorrect. To display all but the first 15 lines, you need to use the tail
command instead of the head
command, so option B is a wrong answer. Also, you need to use tail
to display the last 15 lines of the file, so option D is also an incorrect answer. Option E is a wrong choice because the command will not generate an error message in this case.hal
. Therefore, your best next step is to employ the -i
option on the grep
command. This will quickly search the text file for the word Hal
while ignoring case. Thus, option E is the correct answer. Option A is a wrong choice because the tail
command will not allow you to search the file. Option B is also an incorrect answer, because the cat
command will just display the entire text file to the screen and is not an efficient method for finding a few text lines. While you may end up having to regenerate the text file, prior to doing so you should check for Hal
, ignoring case. If you find the records, then you have saved yourself some time. Thus, option C is also a wrong choice. Finally, the -d skip
option on the grep
command allows the search to skip any directory files. This option is useless in this situation, and therefore option D is an incorrect answer.less
utility is a pager and will allow you to search through the text file, the coworker mentioned pagers, which includes the more
utility. With the more
utility you cannot search through text, so option C is an incorrect choice. You do not need to filter out text in the file, and filter utilities are not called pagers, so option D is a wrong answer. A utility that only allows you to view the last few lines of a file would not be useful in this case, and these utilities are not called pagers. Therefore, option E is an incorrect choice.less
pager utility; therefore, only option E does not describe less
and is the correct answer. Option A is a wrong answer because less
does not read the entire file prior to displaying the file's first page. You can also employ the up and down arrow keys to traverse the file as well as the spacebar to move forward a page and the Esc+V key combination to move backward a page, so options B, C, and D are incorrect answers.-q
(or --brief
) option used with the diff
command will allow you to quickly determine if two text files are different from each other. Thus, option B is the correct answer. The -e
switch allows you to create an ed
script to use later on, so option A is an incorrect choice. The -s
option does allow you to see if the files are the same and shows a simple message stating this fact. However, it is focused on file differences, so it is not the best switch to use. Therefore, option C is also a wrong answer. The diff
command's -W
option allows you to set a display width, and thus, option D is an incorrect choice. The -y
switch displays the two files in two columns, so option E is also a wrong selection.which
command will allow you to quickly see the location of the program you provide as an argument. If you see no response, you can go on to the next troubleshooting step of determining if the program is not installed. Option A is not correct because these actions will simply recall the original diff
command and try it again. Logging out and then back in again may reset some variables you accidentally created, but it is not a good first step in this troubleshooting process. Therefore, option B is a wrong answer. Entering the whereis diff
command will provide additional information concerning the diff
command, such as program location and source code file locations as well as man page locations. This additional information is not needed, so option D is an incorrect choice. Rebooting a server just because a command does not work is not a good first troubleshooting step. Therefore, option E is also a wrong answer.locate
command uses file globbing, which adds wildcards to the pattern you enter. Thus, conf
is turned into *conf*
. Therefore, option E best explains the results and is the correct answer. The locate
command will search for both file and directory names for specified patterns unless options are provided to modify this behavior. Therefore, option A is an incorrect answer. The locate
command does not use the -d skip
switch (the grep
command does use it, though), and thus, option B is a wrong answer. Because the command operated normally, there is not a problem with the locate
database, so option C is an incorrect choice. Also, a regular expression switch was not used in the locate
command, so option D is also a wrong choice.locate
utility searches the mlocate.db
database, which is typically only updated one time per day via a cron
job. Therefore, for this newly created file, the first thing you should do is update mlocate.db
via the updatedb
command, using super user privileges. Thus, option A is the correct answer. After you have updated the database, any of the commands in option B, C, or E should work fairly well, with option B's command being the best choice. However, for the first step, options B, C, and E are wrong answers. Downloading the file again is tedious and time-consuming and can possibly consume disk space unnecessarily. Therefore, option D is an incorrect choice.locate
command, the path
argument is listed first, which is a starting point directory. The find
utility will search through that directory and all its subdirectories (recursively) for the file or files you seek. Also, the -name
switch allows you to search for a file by name, so option D is the correct answer. Option A is incorrect because there is no -r
switch, and no need for one. Option B is not the best command to use in this case because the starting directory is /
, which is the root of the virtual directory structure. It is much better to start at the /etc
directory, since the file is most likely located somewhere in that directory tree. Using the -maxdepth
switch may hamper the search because it sets the subdirectory level to stop the search. Therefore, option C is a wrong answer. Option E is an incorrect choice, because the path
and filename are flip-flopped and the -name
switch is missing.find / -nouser
command will search through the entire virtual directory structure looking for any files that do not have a username associated with them. Since Michael's account and home directory were deleted, any files he owned out in the virtual directory structure will not have a username associated with them, only a user ID (UID). Thus, option E is the best answer. Option A is incorrect because the -name
switch is for file names, not usernames. Option B is also an incorrect answer, because the -user
switch is used to search for files owned by a particular account. Since Michael's account was deleted, his username would no longer be associated with any files. Option C is a wrong answer because you do not know when his files may have experienced data changes, as indicated by the -mmin
switch, and thus this is a bad method for trying to identify them. Option D is an incorrect choice because the find
command is starting the search process in the user's home directory instead of the root (/
) of the virtual directory structure.grep
utility will allow you to search file contents quickly and effectively. Therefore, option C is the correct answer. The which
utility can help you locate a program's location by its name, but it does not search its contents, so option A is an incorrect choice. The whereis
command will search for a file's program location, source code files, and man pages, but it cannot search a file's contents, so option B is also a wrong choice. The locate
utility will search for a file's location using its name, but it cannot search a file's contents, so option D is an incorrect answer. The find
command can find files using a file's metadata, but it does not search inside a file, so option E is a wrong choice.cat -E
command. Therefore, option C is the correct answer. The text file may have been corrupted, but this command does not indicate it, so option A is an incorrect choice. The text file records end in the ASCII character LF and not NUL or $. Therefore, options B and D are incorrect. The text file records may very well contain a $
at their end, but you cannot tell by the situation description, so option E is a wrong answer.cut
command options, fields must exist within each text file record. These fields are data that is separated by a delimiter, which is one or more characters that create a boundary between different data items within a record. Therefore, option E best describes a delimiter and is the correct answer. Option A is made up and is a wrong answer. Option B describes an end-of-line character, such as the ASCII LF. Option C is made up and is a wrong answer. While a single space and a colon can be used as a delimiter, option D is not the best answer and is therefore a wrong choice.vim
and nano
. Therefore, options C and D are the correct answers. The cut
, sort
, and sed
utilities gather the data from a designated text file(s), modify it according to the options used, and display the modified text to standard output. The text in the file is not modified. Therefore, options A, B, and E are incorrect choices.cut
command gathers data from the text file, listed as its last argument, and displays it according to the options used. To define field delimiters as a comma and display each data center monitor's monitor ID, serial number, and location, the options to use are -d "," -f 1,3,4
. Also, since the text file's records end with an ASCII LF character, no special options, such as the -z
option, are needed to process these records. Therefore, option A is the correct choice. Option B uses the unneeded -z
option and is therefore a wrong answer. Option C is an incorrect choice because it reverses the -f
and -d
options. Options D and E are wrong answers because they put the filename before the command switches.grep
, which uses the pattern to filter text. While you may use a series of characters in a grep
PATTERN
, they are not called regular expressions, so option A is a wrong answer. Option B is describing end-of-line characters, and not regular expression characters, so it also is an incorrect answer. While the ?
is used in basic regular expressions, the *
is not (however, .*
is used). Therefore, option C is a wrong choice. Quotation marks may be employed around a PATTERN
, but they are not considered regular expression characters, and therefore option E is an incorrect answer.grep
command employs the correct syntax. It uses the quotation marks around the pattern
to avoid unexpected results and uses the .*
regular expression characters to indicate that anything can be between May 30 and the IPv4 address. No additional switches are necessary. Option A is not the best grep
command because it uses the wrong regular expression of ?
, which only allows one character to exist between May 30 and the IPv4 address. Options C and D are not the best grep
commands because they employ the -i
switch to ignore case, which is not needed in this case. The grep
command in option E is an incorrect choice, because it uses the -v
switch, which will display text records that do not match the PATTERN
.grep
command. An ERE is an extended regular expression and it requires the use of grep -e
or the egrep
command. Options A, B, C, and E are all BRE patterns that can be used with the grep
command, so they are correct choices. The only ERE is in option D, and therefore, it is an incorrect choice.egrep
command. Therefore, option E is the correct answer. Option A will return either a record that ends with Luke
or a record that ends with Laura
. Thus, option A is the wrong answer. Option B is an incorrect choice because it will return either a record that begins with Luke
or a record that begins with Laura
and has one character between Laura
and the Father is
phrase. Option C has the Luke
and Laura
portion of the ERE correct, but it only allows one character between the names and the Father is
phrase, which will not meet the search requirements. Thus, option C is a wrong choice. Option D will try to return either a record that ends with Luke
or a record that ends with Laura
and contains the Father is
phrase, so the egrep
command will display nothing. Thus, option D is an incorrect choice.data.txt
file numerically and save its output to the new file, newdata.txt
, you can either use the -o
switch to save the file or employ standard output redirection with the >
symbol. In both cases, however, you need to use the -n
switch to properly enact a numerical sort. Therefore, both options A and B are correct. Option C is a wrong answer because the command has the newdata.txt
and data.txt
flipped in the command's syntax. Options D and E do not employ the -n
switch, so they are incorrect answers as well.data.txt
and datatoo.txt
files' content one after the other to STDOUT. The cat -n
command will also append line numbers to it, but it will still concatenate the files' content to standard output. Therefore, options C and E are correct. Option A will just display the files' names to STDOUT, so it is a wrong answer. Option B will numerically sort the data.txt
, wipe out the datatoo.txt
file's contents, and replace it with the numerically sorted contents from the data.txt
file. Therefore, option B is an incorrect answer. Option D will show the two files' metadata to STDOUT instead of their contents, so it also is a wrong choice.pr
command's primary purpose in life is to specially format a text file for printing, and it can accomplish the required task fairly quickly. Therefore, option C is the best choice. While the pr
utility can handle formatting entire text files, the printf
command is geared toward formatting the output of a single text line. While you could write a shell script to read and format each text file's line via the printf
command, it would not be the quickest method to employ. Therefore, option A is a wrong answer. Option B's wc
command will perform counts on a text file and does not format text file contents, so it is also an incorrect answer. The paste
command will “sloppily” put together two or more text files side by side. Thus, option D is a wrong answer. Option E is an incorrect choice because the nano
text editor would force you to manually format the text file, which is not the desired action.printf
FORMAT
"%.2f
"
will produce the desired result of 42.78
, and therefore option E is the correct answer. The FORMAT
in option A will simply output 42.777
, so it is an incorrect choice. The FORMAT
in option B will output 42
and therefore is a wrong answer. The printf
FORMAT
setting in option C will produce an error, and therefore, it is an incorrect choice. Option D's printf
FORMAT
"%.2c
"
will display 42
and thus is also an incorrect answer.wc
utility is the number of lines within a designated text file. Therefore, option A is correct. Option C is also correct, because the second item output by the wc
utility is the number of words within a designated text file. Option B is a wrong answer because the file contains 2,020 lines and not characters. Option D is an incorrect choice because you do not know whether or not the Unicode subset of ASCII is used for the text file's encoding. You should always assume the last number is the number of bytes within the file. Use the -m
or --chars
switch on the wc
command to get a character count. Therefore, the file could have 11,328 bytes in it instead of characters. Option E is also a wrong choice because the file has 2,020 lines in it.ls -l
output line. Therefore, option A is a wrong answer. Option C is also wrong, because it is a made-up answer. Option D is incorrect because it describes only STDOUT, which has a file descriptor number of 1 and is only one of several file descriptors. A file indicator code is a symbol that indicates the file's classification, and it is generated by the ls -F
command. Therefore, option E is also a wrong choice./dev/tty
file. Therefore, option D is the correct answer. The /dev/tty
n
file, such as /dev/tty2
, may be your current terminal at a particular point in time, but /dev/tty
always represents your current terminal, so option A is a wrong answer. Option C is incorrect because it is the symbol used at the command line to redirect STDOUT away from its default behavior. The pwd
command displays your present working directory, so option E is a wrong choice.SpaceOpera.txt
file to output as well as save a copy of it to the SciFi.txt
file. Therefore, option A is the correct answer. Option B is a wrong answer because it will only put a copy of SpaceOpera.txt
into the SciFi.txt
file. Option C is an incorrect choice because this will display the SpaceOpera.txt
file to output and put any error messages into the SciFi.txt
file. The cp
command will only copy one text file to another. It will not display the original file to output, so option D is a wrong answer. Option E is a wrong choice because it will put a copy of SpaceOpera.txt
into the SciFi.txt
file and include any error messages that are generated./dev/null
file is also called the black hole, because anything you put into it cannot be retrieved. If you do not wish to see any error messages while issuing a command, you can redirect STDERR into it. Thus, option D is the correct answer. Options A, B, and C are wrong answers because they perform redirection to a file called BlackHole
instead of /dev/null
. Option E is also incorrect, because it redirects STDOUT to the /dev/null
file, and any error messages will be displayed.Problems.txt
file that contain the word error
at least one time, the grep
command is employed. The correct syntax is grep error Problems.txt
. To count the records, the grep
command's STDOUT is piped as STDIN into the wc
utility. The correct syntax to count the records is wc -l
. Therefore, option C is the correct answer. The command in option A is incorrect because its wc
command is counting the number of bytes within each input record. Option B is a wrong answer, because its wc
command is counting the number of words within each input record. The command in option D has two problems. First, its grep
command syntax has the item for which to search and the file to search backward. Also, its wc
command is counting the number of words within each input record. Therefore, option D is a wrong choice. Option E is an incorrect answer because its grep
command syntax has the item for which to search and the file to search backward.xargs
command, $()
method, backticks (`
), and brace expansion all allow you to build a command-line command on the fly. In this case, only options B, C, and E are using the correct command syntax to find any file named 42.tmp
, which exists somewhere in your current directory's tree structure and display its contents to STDOUT. Therefore, options B, C, and E are correct answers. Option A is using the wrong syntax for the xargs
command, and this command will generate an error message. Therefore, option A is a wrong answer. Option D is using the wrong syntax for brace expansion, and thus, it is an incorrect choice as well.vim
editor are command (also called normal mode), insert (also called edit or entry mode), and ex (sometimes called colon commands) mode. Therefore, options A, C, D, and E are correct answers. The only incorrect choice for this question is option B.fsck
program (option B) is used to check and repair damage to hard drives, so it isn't useful until after the Linux system has started. The Windows operating system only starts after a Windows bootloader program can run, so option C is incorrect. The mount
program is a Linux tool for attaching a partition to the virtual directory, which isn't available until after the Linux system starts, so option D is also incorrect. The mkinitrd
program is used to create an initrd RAM disk used for booting, but it isn't run when the workstation starts up, so option E is incorrect.dmesg
, contains messages from the boot messages from the kernel; thus, option D is correct. The fsck
program (option A) fixes corrupted partitions, and the mount
program (option C) is used to attach partitions to the virtual directory, so neither of those is correct. Option B, the init
program, is used to start programs from the kernel, not display boot messages, so it also is incorrect. Option E, the mkinitrd
program, is used to create a new initrd RAM disk and is not related to the boot messages, so it too is incorrect./var/log
folder. The /etc
folder is most often used for storing system and application configuration files, not boot logs, so option A is incorrect. Some Unix systems use the /var/messages
folder for storing log files, but Linux has not adopted this standard, so option B is also incorrect. The /boot
folder contains the GRUB configuration files along with the image files necessary to boot the system, but it's not where Linux stores boot logs and is thus incorrect. The /proc
folder is unique in that the Linux kernel dynamically stores information about the system there, but it doesn't store boot log information there./boot/efi
directory on Linux systems. The UEFI firmware always looks for the /boot/efi
directory for bootloader programs, so option D is correct. The /etc
directory is used to store application and system configuration files, not bootloader programs, so option B is incorrect. The /var
folder is used to store variable files such as log files, not bootable files, so option C is incorrect. Option E, the /boot/grub
file, is used in GRUB Legacy and GRUB2 to store the bootloader configuration files, as well as the kernel image files. However, it is not used to store the bootloader files themselves, so option E is incorrect..efi
file extension to identify them; thus, option E is correct. Option A and option D specify file extensions used to identify GRUB2 (option A) and GRUB Legacy (option D) configuration files, not UEFI bootloader files, so they are both incorrect. Option C specifies the .lst
file extension, which is also used for GRUB Legacy configuration files, so it too is incorrect. The .uefi
file extension is not used in Linux, so option B is incorrect./boot/grub
directory, so option A is correct. Option B, the /boot/efi
directory, is used to store UEFI bootloader programs, not GRUB configuration files, so it is incorrect. Option C, the /etc
directory, stores many application and system configuration files, but not the GRUB Legacy configuration files. The /var
directory stores variable files such as log files but not configuration files, so option D is incorrect. Likewise, Linux uses the /proc
directory to provide dynamic kernel runtime data and not configuration files./boot/grub
directory and the /etc/grub.d
directory, so options B and C are correct. Linux uses the /proc
directory to provide dynamic kernel runtime data and not configuration files, so option A is incorrect. Option D, /boot/efi
, stores UEFI bootloader program files, not GRUB2 configuration files, so it is also incorrect. Option E, /var
, is used to store variable files, such as log files, and not configuration files, so it is incorrect.grub-mkconfig
command combines the configurations defined in the /etc/default/grub
file and all of the files in the /etc/grub.d
folder into a single grub.cfg
configuration file. The mkinitrd
command (option A) is used to create a new initrd RAM disk image file, so it is incorrect. Likewise, the mkinitramfs
command (option B) is also used to create initrd image files on Debian systems, so it too is incorrect. The grub-install
program is used by the GRUB Legacy bootloader to install the bootloader in the MBR or a boot partition, but isn't used to generate the GRUB2 configuration files, and is thus incorrect. Option E is the fsck
program, which checks and repairs hard drive partitions, and is an incorrect answer for this question.grub-install
command installs any configuration changes into the GRUB MBR, so option D is correct. The mkinitrd
command creates a new initrd RAM disk image file, so option A is incorrect. Likewise, the mkinitramfs
command (option B) is also used to create initrd image files on Debian systems, so it too is incorrect. The grub-mkconfig
command is used in GRUB2 systems to create an updated configuration file but not in GRUB Legacy systems, so option C is incorrect. The fsck
program checks and repairs hard drive partitions, so option E is incorrect.single
command parameter instructs the Linux system to start in single-user mode after booting, so option A is correct. The fsck
command checks and repairs hard drive partitions, so option B is incorrect. Both the mkinitrd
and mkinitramfs
commands create initrd RAM disk files, so options C and D are incorrect. The dmesg
command displays the boot messages from the kernel ring buffer, so option E is incorrect.grub-mkconfig
command processes GRUB2 directives stored in the /etc/grub.d
folder to create the /etc/grub2.cfg
configuration file, so option B is correct. The mkinitrd
and mkinitramfs
commands are used to create an initrd RAM disk to store module files, so options A and D are incorrect. The grub-install
command is used in GRUB Legacy to install the GRUB configuration file in the correct location but isn't used in GRUB2, so option C is incorrect. The dmesg
command displays the system boot messages and isn't part of the GRUB2 bootloader, so option E is incorrect.fsck
program can perform a filesystem check and repair multiple types of filesystems on partitions. You should use it on any partition that can't be mounted due to errors. The mount
program (option A) is used to append a partition to a virtual directory; it can't correct a partition that contains errors (and will usually refuse to mount them). The umount
command (option B) is also incorrect. It is used to remove a mounted partition from the virtual directory. Option D (the dmesg
command) displays boot messages, and option E (the mkinitrd
command) crates an initrd RAM disk, so both are incorrect.mount
command allows you to specify both the partition and the location in the virtual directory where to append the partition files and folders. The files and folders contained in the partition then appear at that location in the virtual directory. The umount
command (option B) is used to remove a mounted partition. Option C, the fsck
command, is used to fix a hard drive that is corrupted and can't be mounted; it doesn't actually mount the drive itself. The dmesg
command in option D is used to view boot messages for the system, which may tell you where a hard drive is appended to the virtual directory, but it doesn't actually do the appending. Option E, the kninitramfs
command, creates an initrd RAM disk and doesn't directly handle mounting hard drives to the virtual directory.init
program may exist in the /etc/
, /sbin/
, or /bin/
directory, depending on your distribution and its version, so therefore options B, C, and E are correct. The /etc/rc.d/
directory is used in SysVint systems and is not a location for the init
program, so option A is a wrong answer. The /etc/lib/systemd/
directory is the location of the systemd
program, and thus option D is also an incorrect choice.runlevel7.target
. The legitimate systemd targets, which provide backward SysV init compatibility, go from runlevel0.target
through runlevel6.target
. Therefore, option A is the correct answer. The emergency.target
is a special systemd target unit used to enter emergency mode. When your system goes into emergency mode, the system only mounts the root filesystem and mounts it as read-only. Therefore, option B is a systemd target unit and not a correct answer. The graphical.target
is a legitimate systemd target, which provides multiple users access to the system via local terminals and/or through the network and offers a GUI. Thus, option C is an incorrect choice. The multi-user.target
is also a legitimate systemd target, just like the graphical.target
, except that it does not offer a GUI. Therefore, option D is also a wrong answer. The rescue.target
is like emergency.target
, but it mounts the root filesystem for reading and writing. Therefore, option E is an incorrect choice./etc/systemd/system/
directory. This will prevent any package upgrades from overwriting it and keep the directory precedence from using the unmodified service unit copy, which may reside in the /usr/lib/systemd/system/
directory. The directories in options A and B are made up. The /usr/lib/systemd/system/
directory should only store unmodified unit files, which are provided by default, and thus option D is an incorrect answer. The /run/system/systemd/
directory is also made up.After
directive, set to something like After=Service-B.unit
. Therefore, option E is the correct answer. The Conflicts
directive sets the unit to not start with the designated units. If any of the designated units start, this unit is not started. Therefore, option A is a wrong answer. The Wants
directive sets the unit to start together with the designated units. If any of the designated units do not start, this unit is still started. Therefore, option B is also an incorrect answer. The Requires
directive sets the unit to start together with the designated units. If any of the designated units do not start, this unit is not started. Thus, option C is a wrong choice. The Before
directive sets this unit to start before the designated units. While this should be set in Service-B's unit configuration file, it does not apply, in this case, to Service-A's configuration file. Therefore, option D is also an incorrect answer.Environment
directive and/or the EnvironmentFile
directive for setting environment parameters. Therefore, options B and D are correct answers. The Type
directive sets the unit startup type, which can be, for example, forking
. Thus, option A is a wrong answer. The EnvironmentParam
is a made-up directive. PATH
is an environment variable, which you may modify for your unit's environmental parameters. However, it is not a directive.AllowIsolate=no
setting, the target cannot be used with the systemctl isolate
command. Therefore, option D is the correct answer. Option A's static
is an enablement state displayed for a unit file via the systemctl --list-unit-files
command. Thus, option A is a wrong answer. The AllowIsolate=yes
directive permits the target to be used with the systemctl isolate
command. Therefore, option B is also an incorrect choice. The Type=oneshot
is a service unit directive, and you would not find it in a target unit file. Thus, option C is a wrong answer. Option E's disabled
is also an enablement state, like static
, making option E a wrong choice as well.systemctl reload
. This command will load the service configuration file of the running designated service without stopping the service. Therefore, option A is the best answer. A daemon-reload
will load the unit configuration file and not the service configuration file. The restart
command will stop and immediately restart the service. While this will load the modified service configuration file, it will also disrupt the service for current service users. The mask
command prevents a particular service from starting; the unmask
command undoes the mask command's effects.systemctl enable
command followed by the service unit name. Therefore, option E is the correct answer. The restart
command will stop and immediately restart the service but does not control whether or not a service unit is started at system boot. The start
command will start the service but does not control whether or not a service unit is started at system boot. The isolate
command is used with systemd target units, not service units. Option D's disable
command will set a particular service unit to not start at boot time (disable it from starting).systemctl set-default
command, passing the target name as an argument and using super user privileges. The get-default
command will show you the system's current default target. The isolate
command is used to jump to new targets and not to set default targets. The is-enabled
command displays enabled
for any service that is configured to start at system boot and disabled
for any service that is not configured to start at system boot. It only deals with services, and therefore option D is a wrong choice. The is-active
command also only deals with services.blame
command displays the amount of time each running unit took to initialize, and the units and their times are listed starting from the slowest to the fastest. That way, you can start investigating the units at the list's top. The time
command displays the amount of time system initialization spent for the kernel, and the initial RAM filesystem, as well as the time it took for normal system user space to initialize. However, it does not help you determine which unit configurations may be to blame for the slow boot. The dump
command displays data concerning all the units and the data is not in a format that lets you easily track down what unit takes the most time to initialize at boot. Therefore, option B is an incorrect choice. Option C's failure
is a service state, indicating that the service has failed. The verify
command is handy in that it scans unit files and displays warning messages if any errors are found. However, it does not provide configuration information that can assist you in uncovering the reason a system is slow to boot.runlevel
command shows the previous runlevel, or N
for newly booted. Therefore, the only options that this runlevel
command would show on an older Debian-based Linux distribution system, which uses SysV init, are C and E. Option A is incorrect, because it shows 5
as the current runlevel, and Debian-based distros don't use that runlevel. Option B is also incorrect, because it also shows 5
as the current runlevel. Option D is incorrect because it shows 3
as the current runlevel, and the Debian-based distros do not use that runlevel either./etc/inittab
file within the initdefault
record. Therefore, option A is the correct answer. The /etc/rc.d
is a directory and not a file. Thus, option B is a wrong answer. The rc
file is a script that can reside in either the /etc/init.d/
or the /etc/rc.d/
directory. It runs the scripts that start the various system services when jumping runlevels or booting the system. However, this script does not contain any information concerning the default runlevel. Therefore, options C and D are incorrect choices. The /etc/rc.local
file allows you to issue certain commands or run any scripts as soon as system initialization is completed. However, this script also does not contain any information concerning the default runlevel./etc/init.d/
directory. Therefore, option C is the correct answer. The /etc/rc.d/rc
n
.d/
directories are used on a SysV init system, but they contain symbolic links to the scripts within the /etc/init.d/
directory. Thus, option B is an incorrect answer. Options A, D, and E are all systemd directories. Therefore, they are incorrect choices.init
or the telinit
command to jump to that runlevel and pass them one of the three following arguments: 1
, s
, or S
. Therefore, options A, B, D, and E are correct answers. You cannot use the one
argument to reach runlevel 1, and therefore option C is the only wrong choice.service status
command, passing the service name to it as an argument. This will display the service's current status and allow you to start the troubleshooting process quickly. Therefore, option B is the correct answer. The service start
command will start the designated service, but you do not know whether or not this service was stopped. Thus it is not the best command to use, and option A is an incorrect choice. The service --status-all
command is not the best command to use because it shows the status of all the various services. Thus, option C is a wrong answer. The service stop
command will stop the designated service and provide a FAILED
status if it was already stopped. However, this is not the best way to check a service's status on a SysV init system. The service reload
command will load the designated service's configuration file and provide a FAILED
status if the service is stopped. Yet again, this is not the proper way to check a service's status.chkconfig --levels 35 dhcp on
command. Therefore, option D is the correct answer. Options A and E are incorrect, because you cannot use the service
command to enable SysV init services. Option B is a wrong answer because you cannot use a delimiter, such as a comma, to separate the runlevel list. Option C is an incorrect choice because this command has its service name and the on
argument flip-flopped.update-rc.d dhcp defaults
. Therefore, option E is the correct answer. Option A is incorrect because the last command argument should be defaults
and not default
. Option B is a wrong answer because you cannot use the chckconfig
command on a Debian-based distribution. Option C is an incorrect choice because this command has the service name and the default
argument flip-flopped. Also, it is using the wrong argument—the argument should be defaults
. The command used in option D is incorrect because this command has the service name and the defaults
argument flip-flopped..mount
extension. Therefore, the mount unit file for the /var/log/
mount point would be var-log.mount
. Thus, option C is the correct answer. The /var/log.mount
unit filename is incorrect because the forward slashes were not removed or replaced. The /var/log.unit
base name is incorrect because the forward slashes were not removed or replaced. Also, the wrong file extension is used. The var-log.unit
base name is incorrect because the wrong file extension is used. The var/log.mount
unit filename is incorrect because the middle forward slash was not replaced by a dash.[Automount]
file section are Where
, DirectoryMode
, and TimeOutIdleSec
. Thus, options A, C, and D are correct answers. The Options
and What
directives are ones you would see in a mount unit file's [Mount]
section. Therefore, options B and E are incorrect choices.nmtui
command provides an interactive text menu for selecting a network interface and setting the network parameters, and the ip
command provides a command-line tool for setting network parameters, so both options C and D are correct. The netstat
command displays information about network connections, but it doesn't set the network parameters, so option A is incorrect. The ping
command can send ICMP packets to a remote host but doesn't set the local network parameters, so option B is incorrect. The route
command sets the routing network parameters, but not the IP address or subnet mask, so option E is incorrect.netstat
command doesn't set network information, but instead displays active network connections, so option A is incorrect. The iwconfig
command sets wireless network parameters, but not network address information, so option C is incorrect. The route
command sets default router information, but not network address information, so option D is incorrect. The ifconfig
command does set network address information, but it isn't used by the newer versions of Ubuntu, so option E is incorrect.ethtool
command displays features and parameters for network cards, so option A is the correct answer. The netstat
command displays network statistics and connections, so option B is incorrect. The iwconfig
and iwlist
commands are used to set wireless network parameters and not Ethernet card settings, so options C and D are incorrect. The route
command sets or displays routing information and not Ethernet card settings, so option E is incorrect.ss
command displays a list of the open ports on a Linux system, along with the processes associated with each port, so option E is correct. The iwconfig
command sets wireless network information, not open ports, so option A is incorrect. The ip
command displays or sets network information on a network interface but doesn't display open ports, so option B is incorrect. The ping
command sends ICMP messages to a remote host but doesn't display any open ports, so option C is incorrect. The nmtui
command allows you to configure network parameters for a network interface but doesn't display the open ports on the system, so option D is incorrect.nmcli
and the ip
commands both allow you to set and change network settings from the command line, so options A and C are both correct. The iwconfig
command only sets wireless network information, so option B is incorrect. The netstat
command displays open ports but doesn't change any network settings, so option D is incorrect. The ping
command sends ICMP packets to remote hosts for testing, but it also doesn't set any network settings, so option E is incorrect.ifconfig
command can set the static IP address of the host but doesn't automatically assign the IP address, so option E is incorrect.dig
command can display individual host records for a domain, which you can use to find the MX mail host for the domain, so option A is correct. The host
command only displays host IP address information; it can't determine the server type from the DNS records, so option D is incorrect. The netstat
and ss
commands display active network connections, but not the remote host types, so options B and E are both incorrect. The ping6
command sends IPv6 ICMP packets to test remote hosts but can't tell if the remote host is a mail server, so option C is incorrect.ss
command can display both open ports and the applications that own them, so option B is correct. The ip
and ifconfig
commands just display or set network settings, so options A and E are incorrect. The host
and dig
commands only display hostname information, so options C and D are also incorrect./etc/sysconfig/network-scripts
folder, making option A correct. Option B is where Debian-based systems store the interfaces file, which contains the network configuration settings. The ifcfg-eth0
is a file used to store the configuration, not a folder, so option C is incorrect. The ifconfig
and iwconfig
are commands and not folders, so options D and E are incorrect.iface
setting to set features for an interface, and you must specify the dhcp
option to dynamically obtain an IP address, making option B correct. Options C and E are incorrect since they don't use the iface
setting. Option A sets a static IP address for the interface and not a dynamic address, so it's incorrect. Option D sets a link local IPv6 address and not a dynamic IP address, so it's incorrect./etc/resolv.conf
configuration file using the nameserver setting, so option B is correct. The /etc/dhcpd.conf
file defines configuration settings for a DHCP server, so option A is incorrect. The /etc/nsswitch.conf
file defines the order in which the system searches for a hostname, not the list of DNS servers used, so option C is incorrect. The /etc/network/interfaces
file defines the network interfaces for a Debian-based system, not the list of DNS servers, so option D is also incorrect. The /etc/sysctl.conf
file defines kernel network parameters and not a list of DNS servers, so option E is incorrect.ifconfig
command must specify the network interface, the IP address, then the netmask
option before the netmask address. You can use the up
or down
option to place the network card in an active or inactive state by default, but it's not required. Option A is the only option that uses the correct values in the correct order. Option C is close but fails to specify the network interface. Option B is not in the correct format, and options D and E fail to list the necessary configuration settings.iwlist
command displays the available wireless network access points detected by the wireless network card, so option A is correct. The iwconfig
command configures the network card to connect to a specific access point but doesn't list all of the detected access points, making option B incorrect. Option C specifies the ifconfig
command, which is used to assign an IP address to a wireless network card but doesn't list the access points. The ip
command specified in option D likewise can be used to set the IP address of the card but doesn't list the access points. Option E, the arp
command, maps hardware addresses to IP addresses so that you can find duplicate IP addresses on your network, but it doesn't list the wireless access points.essid
option in the iwconfig
command, making option D the correct answer. The key
option specifies the encryption key required to connect to the access point but not the access point name, making option A incorrect. The netmask
and address
values aren't set by the iwconfig
command, so options B and C are incorrect. The channel
option defines the radio frequency the access point uses, not the access point name, so option E is also incorrect.ip
command allows you to both display and set the IP address, netmask, and default router values for a network interface, so option E is correct. The ifconfig
command can set the IP address and netmask values, but not the default router. The iwconfig
command is used to set the wireless access point settings, and the router
command is used to set the default router but not the IP address or netmask values. The ifup
command only activates the network interface; it can't set the address values.ping
command sends ICMP packets to a specified remote host and waits for a response, making option C the correct answer. The netstat
command displays statistics about the network interface, so it's incorrect. The ifconfig
command displays or sets network information but doesn't send ICMP packets, making option B incorrect. The iwconfig
command displays or sets wireless network information, but it doesn't handle ICMP packets, making option D incorrect. The ss
command displays information about open connections and ports on the system, so option E is also incorrect.tcpdump
command displays network packets that traverse the system network interface, so you can use that for monitoring application packets on the network, making option B the correct answer. The nc
command allows you to manually send packets on the network, but it doesn't allow you to monitor application packets, so option A is incorrect. The ping
and traceroute
commands only send ICMP packets to remote servers; they don't monitor packets, so options C and D are incorrect. The mtr
command can display the connectivity status to a remote server, but it doesn't allow you to view application packets going to the server, so option E is incorrect.brltty
service. The proper systemctl
command to restart the services is in option D. Options A, B, and C all use incorrect names for the braille service. The command in option E would reload any modified brltty
configuration files but not restart the service. Therefore, option E is also an incorrect choice.$WAYLAND_DISPLAY
environment variable, so option B is a correct answer. Also, XWayland supports legacy X11 programs. Therefore, option D is an additional correct answer. Wayland is a replacement for the X11 display server, and it is designed to be more secure. Thus, option A is a wrong answer. Wayland's compositor is swappable and there are several other compositors besides Weston available for use with Wayland. Therefore, option C is a wrong choice. In order to disable Wayland in GNOME Shell, you edit the /etc/gdm3/custom.conf
file and set WaylandEnable
to false
. Thus, option E is also an incorrect answer.loginctl
command will help you determine your current GUI session number. You can then use the loginctl
command again along with your session number to determine if your GUI session is Wayland or X11. Thus, option C is the correct answer. While you can issue the command echo $WAYLAND_DISPLAY
to help determine if your GUI session is Wayland or X11, $WAYLAND_DISPLAY
by itself does nothing. Therefore, option A is a wrong answer. AccessX is a program that originally provided many universal access settings. There is no environment variable used by Wayland or X11 called $AccessX
, and thus, option B is an incorrect answer. The $X11
environment variable is made up, so option D is a wrong choice. The runlevel
command allows you to determine your system's current run level and is not used in determining display servers. Therefore, option E is also an incorrect choice.gnome-shell --replace
, do not work in your GUI session. Therefore, option C is the correct answer. The scenario does not indicate that the X11 display server is hung. So please don't reboot your server and know that option A is a wrong answer. The error message does not indicate that the -R
option should be used instead. Thus, option B is an incorrect answer. If XWayland was being used, you would not receive an error message. Therefore, option D is also a wrong choice. If Wayland was disabled for the session, the command would not generate an error message. Thus, option E is an incorrect choice.X.Org
foundation does develop an X server, called X11. The X server is being replaced by Wayland. X is short for X Window System, which is a display server. So options B, C, and E are correct. XFree86 was the dominant server implementing X until 2004. Now the dominant server is the X.Org
foundation's X11 server, so option A is a wrong answer. The X.Org
's server implements the X Window System version 11, and that is why it is sometimes called X11. It is not due to the number of graphical sessions a particular user can have. Therefore, option D is also an incorrect choice.xwininfo
and xdpyinfo
commands provide information about the X server, including the different screen types available, the default communication parameter values, and protocol extension information as well as individual window information. These two utilities would be the best ones to start diagnosing the problem. Therefore, options A and D are correct answers. Xorg -configure
creates a new X11 configuration file for your perusal, which may be useful later on in the troubleshooting process. However, this is not the best command to start diagnosis. Therefore, option B is a wrong answer. The xcpyinfo
command is made up, making option C an incorrect answer. The loginctl
command can help you determine whether or not the user is using X11 or Wayland, but since you already know that the X display server is running, issuing this command will not help. Thus, option E is an incorrect answer as well.-N
switch is needed. The -f
switch will send the openSSH tunnel into the background, freeing up your command-line interface so that you can type remote desktop commands. The local mode of the ssh
command requires that you use the -L
switch to specify the local system as well as the local and remote ports to be used. Therefore, options A, C, and E are correct. The -X
switch is not used in SSH port forwarding, so option B is a wrong answer. The -R
switch is used for remote mode SSH port forwarding. Therefore, option D is also an incorrect choice.-Y
switch, which is not secure. Therefore, option A is a wrong answer. The command in option C also uses the -Y
switch, so option C is also an incorrect answer. The command in option D uses the correct command switch but sends the connection to the laptop instead of the rack-mounted Linux server. Thus, option D is a wrong answer. The command in option E is using the -L
switch, which is for local SSH port forwarding, and it uses the wrong syntax for that switch and attempts to send the connection to the laptop. Thus, option E is a very incorrect answer.locale
is a Linux command and not a character set, so option E is incorrect.LC_ALL
environment variable defines a character set to use for the Linux system but isn't a character set in itself, so option B is incorrect. Both the UTF-8 and UTF-16 character sets are a subset of the Unicode character set, so they can't represent all the language characters in use in the world, so options C and D are incorrect.locale
command displays all of the LC_
environment variables and their values, so option E is correct. The date
command only displays the time and date, not the localization information, so option A is incorrect. The time
command displays the amount of time an application uses on the system, not the localization information, so option B is incorrect. The hwclock
command displays the hardware clock time, not the localization information, so option C is incorrect. The LANG
environment variable allows you to set all the LC_
environment variables in one place, but it doesn't display all their settings, so option D is incorrect.LANG
and LC_ALL
environment variables control all the localization environment variable settings, so options C and E are correct. The LC_MONETARY
, LC_NUMBERIC
, and LC_CTYPE
environment variables each control a single category of localization environment variables, but not all of the localization environment variables, so options A, B, and D are all incorrect.locale
command allows you to view the character sets, but it doesn't adapt the Linux system to the locale environment, so option A is incorrect. The character set is used to specify language characters, but it doesn't adapt the Linux system to a specific language, so option C is incorrect. Unicode and ASCII are two types of character sets, and they don't adapt the Linux system to a specific language, so options D and E are incorrect.localectl
command is part of the Systemd package and allows you to display and change the localization settings for your Linux system, so option D is correct. The timedatectl
command is also part of the Systemd package, but it only applies to time and date changes and not the localization changes, so option A is incorrect. The time
, date
, and locale
programs are legacy programs and not part of the Systemd package, so options B, C, and E are incorrect.export
command sets the value associated with an environment variable, so option B is correct. The time
command displays the amount of time an application used on the system, not the values of an environment variable, so option A is incorrect. The locale
command displays the values of the localization environment variables but doesn't allow you to change them, so option C is incorrect. The date
command displays and sets the time and date values but not the localization environment variables, so option D is incorrect. The hwclock
command displays and sets the hardware clock but not the localization environment variables, so option E is incorrect.LC_MONETARY
environment variable determines the character set used for displaying monetary values, so option B is correct. The LC_NUMERIC
environment variable determines how Linux displays numeric values, so option A is incorrect. The LC_CTYPE
environment variable determines the default character set used by programs but not necessarily only for monetary values, so option C is incorrect. The LC_TIME
environment variable determines how the Linux system displays time, not monetary values, so option D is incorrect. The LC_COLLATE
environment variable determines how Linux sorts alpha characters, not how it displays monetary values, so option E is incorrect.hwclock
and timedatectl
commands retrieve the time and date from the physical workstation or server, so options B and E are correct. The date
command displays the system time and date, not the time and date set on the physical hardware, so option A is incorrect. The time
command displays the amount of time a program uses on the system, not the physical hardware time and date on the workstation or server, so option C is incorrect. The locale
command displays the localization environment variables and their values, not the hardware time and date, so option D is incorrect./etc/localtime
file to store the appropriate time zone file for the location where the system is running, so option A is correct. The /etc/timezone
file is normally used by Debian-based systems, so option B is incorrect. The /usr/share/zoneinfo
folder stores time zone files that you must copy to the /etc/localtime
file, so option C is incorrect. The /usr/share/timezone
and /usr/share/localtime
folders are incorrect folder names, so options D and E and incorrect./usr/share/zoneinfo
folder contains template files for each of the time zones supported in Linux, so option B is correct. The /etc/localtime
and /etc/timezone
files are the locations where you copy or link the appropriate time zone file to, but neither of them is the template folder, so options A and C are incorrect. The $HOME
folder contains the user environment settings and user files but not the time zone template files, so option D is incorrect. The /usr/share/timezone
folder is an incorrect folder name, so option E is incorrect.timedatectl
command from the Systemd package displays the current date, the Linux system time, the hardware clock time, and the time zone, so option B is correct. The date
command displays the current system time, date, and time zone but not the hardware time, so option A is incorrect. The time
command displays the amount of time an application uses on the CPU, not the current date and time, so option C is incorrect. The hwclock
command displays the current hardware time but not the system time, date, or time zone, so option D is incorrect. The localectl
command displays the localization settings for the system but not the time, date, hardware time, or time zone, so option E is incorrect.date
command allows you to specify a format for displaying the time and date, so option A is correct. The time
command displays the amount of CPU time an application consumes, not the current time and date, so option B is incorrect. The timedatectl
command displays the current time and date but doesn't allow you to format the output, so option C is incorrect. The localectl
command displays the localization settings for the system, but not the current time and date, so option D is incorrect. The hwclock
command displays the current hardware time but doesn't allow you to specify the format, so option E is incorrect.hwclock
and timedatectl
commands allow you to synchronize the Linux system time to the workstation BIOS time, so options A and D are correct. The date
command allows you to change the date and time, but it doesn't allow you to synchronize it with the workstation BIOS time, so option B is incorrect. The time
command allows you to display the amount of CPU time an application consumes, but it doesn't allow you to synchronize the system time with the workstation BIOS time, so option C is incorrect. The localectl
command is used for localization, not for setting the time, so option E is incorrect.chrony
software package for connecting to network time servers. The ntpd
package is a legacy software package and not often used, so option A is incorrect. The localectl
command isn't used for setting time, so option C is incorrect. While you can set the local time using the timedatectl
command, you can't use it to set the time using a network time server, so option D is incorrect. Although Red Hat–based systems utilize the Systemd utilities, they don't use the timesyncd
program for network time, so option E is incorrect.TZ
environment variable overrides the default system time zone for session applications, so option E is correct. The LANG
and LC_ALL
environment variables set the entire system time zone, not just the programming environment, so options A and D are incorrect. The LC_MONETARY
and LC_NUMERIC
environment variables set the localization for money values and numeric values, but they don't change the time zone setting, so options B and C are incorrect.locale
command displays the localization environment variables and their values—it is not a character set code, so option E is incorrect.localectl
command uses the list-locales
option to display all the localizations installed on the Linux system, so option B is correct. The timedatectl
command displays the local time and date, but it doesn't provide information on which localization files are installed, so option A is incorrect. The locale
command displays the localization environment variable settings but doesn't list which localizations are installed, so option C is incorrect. The LANG
and LC_ALL
environment variables set the current localization but can't display which ones are installed on the system, so options D and E are incorrect.x
), and UID are all legitimate fields in an /etc/passwd
file record. Therefore, options A, B, and E are correct answers. The password change date and special flag are fields in the /etc/shadow
file. Thus, options C and D are incorrect choices./etc/shadow
file record. Therefore, options A, B, and C are correct answers. The comment and default shell are fields in the /etc/passwd
file. Thus, options D and E are incorrect choices./etc/passwd
and an /etc/shadow
record that contains the same data. Therefore, option E is the correct answer. While both files have a password field, they do not contain the same data. The password can only exist in one of the two files, preferably the /etc/shadow
file. Thus, option A is a wrong answer. The account expiration date only exists in the /etc/shadow
file, so option B is also a wrong choice. The UID and GID fields only exist in the /etc/passwd
file, so options C and D are also incorrect answers.cat /etc/passwd
command would allow you to view the NUhura
account's record within the /etc/passwd
file. The grep NUhura /etc/passwd
and getent passwd NUhura
commands also would allow you to see the NUhura
record. So options B, D, and E are correct choices. The getent
command in option A has got the username and filename flip-flopped, so it is an incorrect choice. Also, the passwd NUhura
command attempts to change the account's password instead of display its file record, so option C is also an incorrect answer.useradd -D
command allows you to view the account creation configuration directives in the /etc/default/useradd
file. Therefore, option E is the correct answer. The /etc/passwd
, /etc/shadow
, and /etc/group
files do not contain account creation configuration directives, so options A, B, and C are wrong answers. While the /etc/login.defs
file does contain account creation configuration directives, you cannot display it with the useradd -D
command. Therefore, option D is also an incorrect choice.CREATE_HOME
directive is not set or it is set to no
, when a user account is created no home directory will be created by default. Most likely this caused the problem, so option C is the correct answer. The HOME
directive determines what base directory name is used when creating home directories for new accounts, so option A is a wrong answer. If you did not employ super user privileges, you would not have been able to even create the account, so option B is a wrong choice. The INACTIVE
directive pertains to when an account will be considered inactive, so option D is also an incorrect answer. The EXPIRE
directive is involved with account expiration and not home directory creation. Therefore, option E is also an incorrect choice.KSingh
account and all his home directory files, using super user privileges you would use the userdel -r KSingh
command. Therefore, option D is the correct answer. There is no -r
option for the usermod
command, so option A is a wrong answer. The rm -r /home/KSingh
command would only remove the account's home directory files and not delete the user account. Therefore, option B is an incorrect answer. The userdel
command without any options would only delete the account and not remove any of its home directory files, so option C is a wrong choice. The -d
option on the usermod
command is for changing an account's home directory. Therefore, option E is also an incorrect choice.passwd
, usermod
, userdel
, and chage
commands can all manipulate (or remove) an account's /etc/shadow
file record data in some way. Therefore, options A, B, C, and E are all correct. While the getent
command will allow you to display selected records from the /etc/shadow
file, it will not allow you to manipulate data records within the file. Therefore, option D is the only incorrect choice.newgrp
command will let you switch temporarily from your account's default group to another group with whom you have membership. Therefore, option B is the correct answer. The usermod
command could make that switch, but it is not best for temporary situations, so it is an incorrect choice. The groups
command allows you to display group information, but not change groups, so it also is a wrong answer. The groupadd
and groupmod
commands deal with group management, but not temporarily switching an account's default group. Therefore, options D and E are also incorrect choices.usermod -aG NCC-1701 JKirk
command would add JKirk
to the NCC-1701
group as a member and not remove any of the account's previous group memberships. Therefore, option C is the correct answer. The usermod -g NCC-1701 JKirk
command would change the JKirk
account's primary group membership, so option A is a wrong answer. The command in option B would add the JKirk
account as a member to the NCC-1701
group, but it would remove any of the account's previous group memberships. Thus, option B is an incorrect answer. The groupadd NCC-1701
command would only add the NCC-1701
group. Therefore, option D is a wrong answer as well. The groupmod
command is for modifying groups, and so the command in option E would have undesirable results. Thus, option E is an incorrect choice.getent group NCC-1701
and grep NCC-1701 /etc/group
commands would both allow you to see the various NCC-1701
group members. Therefore, options B and D are correct answers. The groups
command is for viewing an account's various group memberships. Therefore, option A is a wrong answer. It is always tempting to add an s to the /etc/group
filename, because of the groups
command. However, it is the group
file and not the groups
file. Thus, options C and E are incorrect choices./etc/skel
, typically contains the user environment files that are copied to the account's home directory when it is created. Therefore, option A is the correct answer. Options B, C, and D all contain references to home (or potential home) directories. That is where the user environment files end up, but not where they come from. Thus options B, C, and D are wrong answers. The /etc/
directory is where the global environment files reside. Therefore, option E is also an incorrect choice..bash_profile
user environment file is run first if it is found in the user account's home directory. Therefore, option E is the right answer. The .bash_login
and .profile
user environment files would be ignored if they existed alongside the .bash_profile
file within the user's home directory. Thus, options A and C are wrong answers. The .bashrc
file is typically called to execute from one of the other user environment files for an interactive login session. Thus, option B is also an incorrect answer. The .bash.bashrc
file, though similar in name to a global environment file, does not exist. Therefore, option D is an incorrect choice.whoami
, who am i
, and id
commands will all display information about the current account that is issuing the commands. Therefore, options A, B, and E are correct answers. While the cat
commands may display user environment files in the account's home directory, they do not display information concerning the account. Thus, options C and D are incorrect choices.w
command displays CPU load information for the last 1, 5, and 15 minutes as well as data about users who are currently accessing the system. Therefore, option D is the correct answer. The who
command will display information concerning users who are currently logged into the system, but not CPU load data. Thus, option A is a wrong answer. The id
command displays user account information, not CPU load data or active user info. Therefore, option B is also a wrong choice. The whoami
command only displays the username of the current user issuing the command. Thus, option C is an incorrect answer. The last
command displays past and present system access information for user accounts but nothing concerning CPU load data. Thus, option E is an incorrect choice.last
command by default pulls its data from the /var/log/wtmp
file. Therefore, option B is the correct answer. The w
command uses data from the /var/run/utmp
file, so option A is a wrong choice. The last
command can pull information from an older saved wtmp
file, such as /var/log/wtmp.1
, but it does not do so by default. Thus, option C is a wrong choice. The /etc/shadow
and /etc/passwd
files do not contain any data that can be used with the last
command. Therefore, options D and E are incorrect answers.usrquota
and grpquota
options are /etc/fstab
settings used to enable user and group quotas for a filesystem. Therefore, options A and C are correct answers. Options B and D contain commands that are used with managing filesystem quotas. Thus, options B and D are wrong answers. The aquota.user
is a file that is created when the quotacheck -cu
command is employed. Therefore, option E is an incorrect choice.quotaoff -a
command. Therefore, option B is the correct answer. Editing the /etc/fstab
would take too long because you would have to remove the quota options and then unmount and remount all the filesystems. Thus, option A is a wrong answer. The quotacheck
utility creates either the aquota.group
file, if the -cg
options are used, or the aquota.user
file, if the -cu
switches are used, or both files if -cug
is employed. However, it does nothing for quickly turning off filesystems' quotas. Thus, options C and D are incorrect answers. The umount
command will not turn off filesystems' quotas, and therefore option E is also an incorrect choice.edquota -t
command will edit quota grace periods. Therefore, option C is the right answer. The edquota -u
command edits a designated user's quota limits. Thus, option A is a wrong answer. The edquota -g
command edits a designated group's quota limits. Therefore, option B is also an incorrect answer. The edquota -G
command and edquota --grace
command are made up. Thus, both options D and E are incorrect choices.sd
x
in the /dev
folder for SCSI devices. For the second SCSI device, Linux would create the file /dev/sdb
, so option B is correct. The /dev/hdb
file would represent the second HDD drive connected to the system, so option A is incorrect, and /dev/sda
would represent the first SCSI device connected to the system, so option E is incorrect. Options C and D both represent partitions and not entire drives, so they are both incorrect.udev
program runs in the background on Linux systems and detects and mounts storage devices as they're connected to the system, so option E is correct. The mkfs
program creates a filesystem on partitions; it doesn't mount them, so option A is incorrect. The fsck
program repairs filesystems but doesn't mount them, so option B is incorrect. The umount
program unmounts filesystems, not mounts them, so option C is incorrect. The mount
program manually mounts filesystems but doesn't run in the background and automatically detect them, so option D is incorrect.udev
program creates files in the /dev/disk/by-id
folder that are linked to the raw device files for storage devices. These files are identified by manufacturer information, including the serial number assigned to the device, so option C is correct. The /dev/disk/by-path
folder links files based on the drive's connection to the system, so option A is incorrect. The /dev/sdb
file represents the raw device file assigned to the device, not a permanent link file, so option B is incorrect. The /dev/disk/by-uuid
folder contains permanent link files based on the device UUID value, not the serial number, so option D is incorrect. The /dev/mapper
folder contains files for virtual drives for LVM and multipath systems, not permanent links to raw device files, so option E is incorrect.gparted
program provides a graphical window for managing device partitions, so option B is correct. The gdisk
, fdisk
, and parted
programs are all command-line partitioning tools, so options A, C, and D are all incorrect. The fsck
program is a tool to repair filesystems, not create or modify partitions, so option E is incorrect./dev
files are used as raw devices for storage devices; they don't access the filesystem, so option C is incorrect. The /proc
and /sys
folders are used by the kernel to display and change storage device information, not add the filesystem to the virtual directory, so options D and E are incorrect.mkfs
program allows you to create a new filesystem on a partition, so option B is correct. The fdisk
, gdisk
, and parted
programs are used to create or modify partitions but not to work with the filesystem installed on them, so options A, D, and E are all incorrect. The fsck
program repairs filesystems but can't create them, so option C is incorrect.mount
program allows you to insert the filesystem on a partition into the virtual directory, so option B is correct. The fsck
program repairs filesystems but doesn't insert them into the virtual directory, so option A is incorrect. The umount
program removes filesystems from the virtual directory, as opposed to inserting them, so option C is incorrect. The fdisk
program partitions devices but doesn't create filesystems or insert them into the virtual directory, so option D is incorrect. The mkfs
program creates filesystems but doesn't insert them into the virtual directory, so option E is also incorrect.fsck
program repairs corrupted filesystems, so option A is correct. The mount
program inserts filesystems into the virtual directory, but it can't repair them, so option B is incorrect. The umount
program removes filesystems from the virtual directory but can't repair them, so option C is also incorrect. The fdisk
program creates and modifies partitions but doesn't work with filesystems, so option D is incorrect. The mkfs
program creates filesystems but doesn't repair them, so option E is incorrect.gzip
utility compresses data files and gives them the .gz
file extension. Therefore, option B is the correct answer. The xz
, bzip2
, and zip
compression utilities compress a data file and give it a different file extension, so options A, C, and D are wrong answers. The dd
utility is not a compression program. Therefore, option E is also a wrong choice.cpio
program. This is because you can employ the find
command to locate the files and then pipe the results into the cpio
utility. Therefore, option D is the correct answer. While the tar
utility uses SNAR files, it is not the most efficient program to use in this scenario, and thus, option A is a wrong answer. The dd
utility is used for entire disks or partitions, and therefore, option B is an incorrect answer. The rsync
and zip
programs are not the most efficient utilities to use in this scenario, so options C and E are also incorrect choices.tar
options -cJvf
will create a tarball using the highest compression utility, xz
, and allow the administrator to view the files via the verbose option while they are being copied into the compressed archive. Thus, option E is the correct answer. The switches in options A and B perform extracts (-x
) and do not create, so they are wrong answers. The only thing wrong with option C is that it employs gzip
compression via the -z
switch, so it is an incorrect choice. Option D leaves out the verbose switch, so it too is an incorrect choice.dd
command in option A will accomplish the job correctly and is the correct answer. The dd
commands in options B through D have the input and output files flip-flopped, so they would destroy the data on the /dev/sdc
drive. Therefore, options B, C, and D are wrong answers. The dd
command in option E would wipe the /dev/sdc
drive using zeros. Therefore, option E is also an incorrect choice.-a
switch allows you to recursively back up a directory tree and preserves all the file metadata. It is equivalent to using the -rlptgoD
switches. Therefore, option C is the correct answer. The -r
switch only allows recursive operations but does not preserve metadata, such as file ownership. Therefore, option A is a wrong answer. The -z
switch employs compression and nothing else, so option B is a wrong choice. The -e
and --rsh
switches are used to designate a remote program to use when sending files to a remote system. Thus, options D and E are also incorrect choices.-z
switch in conjunction with the rsync
utility, you are employing compression from the zlib
library. Therefore, option E is correct. And thus, options A, B, C, and D are incorrect choices.scp
utility and therefore are correct answers. The scp
program is not an interactive utility, and so option C is a wrong answer. Also, the scp
utility cannot be interrupted without ill effects (you have to start all over), so option D is also an incorrect choice.reput
command will resume your interrupted operation of uploading a local backup to a remote system. Therefore, option E is the correct answer. The progress
command toggles on and off the progress display, so option A is a wrong answer. The get
command and the reget
command involve downloading a file from a remote system to a local system. Thus, options B and C are wrong choices. Though the put
command was probably used prior to the operation's start, it will not resume an upload, so option D is also an incorrect choice.sftp
utility or wrong switches on the md5sum
program will not typically cause corruption. Therefore, options C and E are wrong choices. The numbers only match if corruption has not occurred, and thus, option D is also an incorrect choice.tar
and gzip
utilities, you often need to download the file from a website. The wget
and cURL
programs allow you to download files from the command line, so options A and B are correct. The dpkg
tool is used for installing DEB package files, not tarballs, so option C is incorrect. The rpm
and yum
tools are used for installing RPM package files, so options D and E are incorrect.make
script runs the necessary compiler steps to compile all of the source code and library files necessary to build the application executable file, so option D is correct. The dpkg
tool installs DEB package files, not source code files, so option A is incorrect. The rpm
and yum
tools are used to install RPM package files, so options B and C are incorrect. The wget
program is used to download source code bundles, but not build them, so option E is incorrect.configure
tool assesses your Linux system to ensure that any dependencies are met and that the proper compiler tools are installed and then builds the make
script, so option C is correct. The make
script along with the install
option runs the make
script but doesn't create it, so options A and B are incorrect. The gcc
program compiles the source code and library files but doesn't create the make
script, so option D is incorrect. The dpkg
installs DEB package files but doesn't create a make
script, so option E is incorrect.gcc
) is the most popular compiler used in Linux, so option A is correct. The make
utility runs make scripts to help build applications using gcc
, but it doesn't compile the source code directly, so option B is incorrect. The configure
utility helps build the make
script based on the location of the compiler program, but it doesn't compile the source code, so option C is incorrect. The dpkg
and rpm
programs are package tools for installing DEB and RPM package files, respectively, and aren't used to compile source code files, so options D and E are both incorrect.tar
, application is often used for bundling source code projects into a single distributable file, so option E is correct. The dpkg
, rpm
, yum
, and apt-get
programs all work with package management files, and are not for archiving source code files, so options A, B, C, and D are all incorrect.-zxvf
command-line options for the tar
program are commonly used to decompress and extract files from a tarball file, so option B is correct. The -Uvh
option group is commonly used for the rpm
program to install packages, but it's not valid for the tar
program, so option A is incorrect. The -xvf
command-line option combination extracts files from a tarball but doesn't decompress them, so option C is incorrect. The -zcvf
option group will create a new tarball and compress it, not extract and decompress the files, so option D is incorrect. The -cvf
option group creates a new tarball file, but it doesn't extract files from an existing file, so option E is incorrect..deb
filename extension is used to identify Debian-based package management files, so option A is incorrect. The .tgz
filename extension is used to identify compressed tar archive files, so option C is incorrect. The .tar
filename extension is used to identify tar archive files, so option D is incorrect, and the .gz
filename extension is used to identify files compressed with the gzip
utility, so option E is incorrect.dpkg
program is used to install DEB package files on Debian-based systems, so option D is correct. The rpm
, yum
, and dnf
programs are all tools used for Red Hat–based package management systems, not Debian-based systems, so options A, B, and C are all incorrect. The tar
program is used for creating and extracting tarball archive files, not DEB files, so option E is incorrect.yum
and dnf
programs are used to install RPM packages from Red Hat–based repositories, so options C and E are correct. The dpkg
and apt-get
programs are used for installing DEB files on Debian-based package management systems, so options A and D are incorrect. The tar
program is used for creating and extracting archive files, so option B is incorrect./lib/modules/
KernelVersion
/
or /usr/lib/modules/
KernelVersion
/
. If the /usr/lib/modules/
KernelVersion
/
directory is used, it is typically hard-linked to the /lib/modules/KernelVersion/
directory. Therefore, options B and D are correct answers. The other directory names are made up. Thus, options A, C, and E are incorrect choices./etc/modules.conf
. On more modern distributions, configuration information is stored in *.conf
files within the /etc/modprobe.d/
, /lib/modprobe.d/
, /usr/lib/modprobe.d/
, and run/modprobe.d/
directories. Therefore, options A, B, D, and E are all correct answers. The /etc/modules.d/
directory is made up, and thus option C is an incorrect choice.modinfo
utility will allow you to view detailed information concerning a module passed as a command argument. This detailed information includes any dependencies. Therefore, option E is the correct answer. The dmesg
command is helpful for viewing any kernel messages concerning module failures but does not display module dependency information. Thus, option A is a wrong answer. The insmod
utility is used for loading modules dynamically, and therefore, option B is a wrong choice. The lsmod
command displays currently loaded modules. While it does show other modules that are currently using the module, because it does not list dependencies or show information for unloaded modules, it is not the best choice. Thus, option C is also an incorrect answer. The modprobe
utility is used for loading and unloading kernel modules, and therefore, it is not the best choice either. Thus, option D is an incorrect choice.modprobe
utility will dynamically load the xyz
utility, if you pass it as an argument to the command, and also load any of its needed dependencies. Therefore, option C is the correct answer. The insmod
utility is used for loading modules dynamically. However, it will not load any of the module's dependencies, and therefore, option A is an incorrect choice. The modinfo
utility allows you to view detailed information concerning a module passed as a command argument, but it does not load modules. Therefore, option B is a wrong answer. The lsmod
command displays currently loaded modules, and thus option D is an incorrect answer. The depmod
command is used for scanning through the system in order to update the modules.dep
file. Therefore, option E is also an incorrect choice.depmod
command will scan through the system looking for any hardware that was not automatically detected. It determines any needed modules, reviews the modules' dependencies, and updates the appropriate file. Therefore, option D is the correct answer. The lsmod
command displays currently loaded modules, and thus option A is an incorrect answer. The modinfo
utility allows you to view detailed information concerning a module passed as a command argument. However, if you don't know the device's associated module, this utility is of little use. Therefore, option B is a wrong choice. The dmesg
command is helpful for viewing any kernel messages concerning module failures, so if it is a module failure issue, you can view it using this command. However, since the device was not detected, it is not the best command to start the troubleshooting process. Therefore, option C is a wrong answer. The insmod
utility is used for loading modules dynamically, and therefore, option E is an incorrect choice.modprobe
utility uses the modules.dep
file to determine any module dependencies. Therefore, option A is the correct answer. The other options contain directories involved in the kernel module management, and thus options B, C, D, and E are wrong choices.insmod
utility will allow you to quickly insert a module, whose name is passed as an argument to the command, into the Linux kernel. Therefore, option E is the correct answer. The lsmod
command displays currently loaded modules, and thus option A is an incorrect answer. The modinfo
utility allows you to view detailed information concerning a module passed as a command argument, but it does not load modules. Therefore, option B is a wrong answer. The dmesg
utility displays the kernel's ring buffer but does not allow you to insert modules into it. Thus, option C is also a wrong choice. The depmod
command is used for scanning through the system in order to update the modules.dep
file. Therefore, option D is also an incorrect choice.rmmod
command will quickly unload a module, but none of its dependencies, from the Linux kernel. Since the abc
module does not have any dependencies, option C is the best answer. The insmod
utility is used for loading (inserting) a module and not unloading one. Therefore, option A is a wrong answer. The unload
command is made up, and thus option B is also an incorrect answer. The modprobe
command used without any switches is for loading (inserting) modules, not unloading them. Thus, option D is a wrong choice. The rm -f
command is used in removing files, not unloading modules. Therefore, option E is an incorrect answer.modprobe -r
command will remove the module whose name is passed to it as an argument and any of its dependent modules. Therefore, option B is the best answer. The dmesg
command is helpful for viewing kernel messages related to module failures but not for unloading modules. Thus, option A is a wrong answer. The lsmod
utility shows brief module information for loaded modules but is not involved in the unlinking process. Therefore, option C is also an incorrect answer. The paste
command allows you to sloppily put together two files side by side to STDOUT. However, it is not involved with kernel modules, so option D is also a wrong choice. The groupdel
utility is used for removing user groups, and it also is not used with kernel modules. Therefore, option E is an incorrect choice.rw-r--r--
, so option E is correct. Option A, rwxrw-r--
, would be octal mode 764, so it is incorrect. Option B, -w--w--w-
, would be octal mode 222, so it is incorrect. Option C, -w-r--r--
, would be octal mode 244, so it is also incorrect. Option D, rwxrw-rw-
, would be octal mode 766, so it too is incorrect.chgrp
command is used to change the group assigned to a file or directory; however, you can also specify a new group with the chown
command to change the owner and the group at the same time, so both options A and B are correct. The chmod
command changes the permissions assigned to a file or directory but not the group, so option C is incorrect. The chage
command is used to control the password of user accounts, not the group assigned to a file or directory, so option D is incorrect. The ulimit
command is used to restrict the system resources a user account can use, not to set the group assignment of a file or directory, so option E is incorrect.getfacl
command retrieves all of the ACL permissions assigned to a file or directory, so option C is correct. The -Z
option added to the ls
command displays SELinux context settings, not ACL permissions, so option A is incorrect. The -l
option of the ls
command displays the standard Linux file permissions, not the ACL permissions, so option B is incorrect. The chmod
command allows you to change the standard permissions assigned to a file or directory, not display the ACL permissions, so option D is incorrect. The setfacl
command allows you to change the ACL permissions for a file or directory, but not view them, so option E is incorrect.-Z
option of the ls
command displays the SELinux security context assigned to a file or directory, so option C is correct. The getsebool
command displays the current setting for a policy rule, not the security context of files, so option A is incorrect. The setsebool
command enables or disables a policy rule, and it doesn't display the security context of a file, so option B is incorrect. The getenforce
command displays the current SELinux mode, not the security context of files, so option D is incorrect. The -l
option of the ls
command displays the standard permissions assigned to a file, not the SELinux security context of the file, so option E is incorrect.su
command allows you to run an application as another user, including the root user account, and the sudo
command allows you to run an application as the root user account, so options A and D are both correct. Both wheel
and adm
are user groups that provide administrator privileges, but they aren't commands that run applications themselves, so options B and E are both incorrect. The visudo
command opens an editor to edit the sudoers file so you can edit it, but it can't run other applications, so option C is incorrect.wheel
group and Debian-based distributions use the sudo
group to allow members to gain administrator privileges on the system to run applications, so options C and D are correct. The lp
group is used to grant access to system printers, not run applications with administrator privileges, so option A is incorrect. The adm
group is commonly used in Debian-based systems to grant access to log files, but not run applications with administrator privileges, so option B is incorrect. Option E, su
, is a command-line command for running commands as another user, not a user group, so it is incorrect.libpam
(also called libpam.so
) library. Thus, option D is the correct answer. Option A lists the ldd
command, which allows you to view modules compiled with various applications. Therefore, option A is a wrong answer. Options B, C, and E are all PAM modules, but none are the PAM library module needed to make an application PAM-aware. Therefore, options B, C, and E are incorrect choices.requisite
, required
, sufficient
, and optional
are all PAM control flags you may find in a PAM /etc/pam.d/
configuration file. Therefore, options A, B, D, and E are correct. Option C, allowed
, is made up and thus an incorrect choice.pam_tally2
and faillock
commands display failed login attempts, and therefore options B and E are correct answers. The tally2
command does not exist, and thus option A is a wrong answer. The pam_tally2.so
module is involved with locking out accounts due to failed login attempts, but it does not display failed logins. Therefore, option C is a wrong choice. The pam_faillock
is made up, and thus, option D is also an incorrect choice.~/.ssh/known_hosts
file. Therefore, option A is the correct answer. The ~/.ssh/authorized_keys
file is used on an SSH server to keep track of authorized public keys used for password-less authentication. Therefore, option B is a wrong answer. Options C and D are made up and therefore incorrect choices. Option E is an RSA public key that could be created by the ssh-keygen
utility, so it is a wrong choice as well.~./ssh/config
, /etc/ssh/ssh_config
, and /etc/ssh/sshd_config
files are all OpenSSH configuration files. Therefore, options A, B, and C are correct choices. The files listed in options D and E are made up and therefore incorrect answers.id_
type
for the private key and id_
type
.pub
for the public key. The key in option E is a private key using the RSA algorithm. Option A's key is an RSA private key used in establishing a password authenticated SSH connection, so it is a wrong answer. The key listed in option B is a public version of option A's key, so it too is a wrong choice. The keys listed in options C and D are made up, and thus they are wrong choices as well.ALL: ALL
in the /etc/hosts.allow
file because it would block everyone from accessing the service. Instead, you would want to place this record in the /etc/hosts.deny
file to provide the best security because it is checked last. Therefore, option B is a wrong choice.journalctl
, is a tool used to read systemd-journald
journal files, not a protocol for logging event messages, so it is also incorrect.cron
application schedules jobs on Linux systems, so the cron
facility keyword represents event messages received from the job scheduler, so option A is correct. The user
keyword represents events received from users, so option B is incorrect. The kern
keyword represents events received from the kernel, so option C is incorrect. The console
keyword represents events received from a console on the system, so option D is incorrect. The local0
keyword is not defined in the standard and is normally defined within the system but doesn't normally receive events from the job scheduler, so option E is incorrect.emerg
severity level has a priority of 0, the highest level in syslog, so option C is correct. The crit
severity level is at level 2, so it's not the highest level and therefore option A is incorrect. The alert
keyword is assigned level 1, but it's not the highest level, so option B is incorrect. The notice
keyword is assigned level 5 and is not the highest level, so option D is incorrect. The err
keyword is assigned level 3 and is not the highest level, so option E is incorrect.notice
severity level represents system event messages that are significant but normal, so option B is correct. The crit
and alert
keywords represent event messages that are critical or that require special attention, so options A and D are incorrect. The info
keyword represents event messages that are only informational but not significant, so option C is incorrect. The local0
keyword is not defined in the syslog protocol but by the local system, so option E is incorrect.rsyslogd
application was designed to be a faster version of the syslogd
application, so option E is correct. The syslogd
application is the original syslog application and was not known for its speed, so option A is incorrect. The syslog-ng
application was designed to be more versatile than syslogd
, but not faster, so option B is incorrect. The systemd-journald
application is known for faster queries in reading journal entries but wasn't designed to be faster in handling event messages, so option C is incorrect. The klogd
application is part of the original sysklogd
application and is also not fast, so option D is incorrect.rsyslogd
application uses the rsyslog.conf
configuration file by default, so option A is correct. Option D, rsyslog.d
, is commonly used as a folder for storing additional rsyslogd
configuration files, but it isn't the default configuration filename, so it is incorrect. Options B and C are configuration files for other logging applications, not rsyslogd
, so they are incorrect. Option E is not a valid logging application configuration filename.rsyslogd
application priorities log event messages with the defined severity or higher, so option D would log all kernel event messages at the warn
, alert
, or emerg
severities and therefore it is correct. The option A facility and priority setting would only log kernel messages with a severity of warning, so it is incorrect. Option B would log all kernel event messages, not just warnings or higher, so it is incorrect. Option C would log all facility type event messages but include the information or higher level severity, so it is incorrect. Option E would log kernel event messages but only at the alert or emerg severity levels, not the warning level, so it is incorrect.Storage
setting controls how systemd-journald
manages the journal file. Setting the value to persistent
ensures that the journal file will remain in the /var/log/journal
directory, so option B is correct. Setting the value to auto
only ensures that the journal file will be persistent if the /var/log/journal
directory exists, so option A is incorrect. Setting the value to volatile
ensures that the file does not persist, so option D is incorrect. Options C and E refer to settings that control whether or not event messages are passed to the rsyslogd
application, so they are both incorrect.-r
option displays the journal entries in reverse order, so the most recent entry will appear first. Thus, option C is correct. The -a
option displays all of the data fields, but in the normal order, so option A is incorrect. The -l
option displays all printable data fields, but in the normal order, so option B is incorrect. The -e
option jumps to the end of the journal file but displays the remaining entries in normal order instead of reverse order, so option D is incorrect. The -n
option displays a specified number of entries, but in normal order, so option E is incorrect.journalctl
application allows you to filter event messages related to a specific application by the application process ID (PID) using the OBJECT_PID
match, so option A is correct. The Kernel
match retrieves event messages generated by the system kernel and not applications, so option B is incorrect. The _TRANSPORT
option filters event messages based on how they were received and not by application, so option C is incorrect. Option D, _UID
, filters event messages based on the user ID value, not the application, so it is incorrect. Option E, _UDEV
, filters events by device ID and not by application, so it too is incorrect.netfilter
embedded in the Linux kernel and not iptables
(which is instead a firewall service), so option D is also an incorrect choice.firewalld
, network traffic is grouped into a zone, which is a predefined rule set, also called a trust level. Therefore, option E is the correct answer. While firewalld
does employ the netfilter
and the firewall-cmd
commands, those items are not predefined rule sets, so options A and B are wrong answers. A service is a predefined configuration set for a particular service, such as DNS. Therefore, option C is an incorrect answer as well. Option D is an incorrect choice because the zone that rejects packets is called block
.firewalld
's runtime environment is the active firewall, but if the configuration is not saved as the permanent environment, it is not persistent. Therefore, after his successful tests, he should issue the firewall-cmd --runtime-to-permanent
command to save the runtime environment to the permanent environment. Thus, option D is the correct answer. Rebooting the system would lose the tested runtime environment, so option A is a wrong answer. The --panic-on
option blocks all incoming traffic, so option B is also an incorrect answer. The runtime environment is different than the permanent environment in this situation, so option C is a wrong choice. While the --permanent
option will allow you to modify the runtime and permanent environment at the same time, Peter did not do this, so option E is also an incorrect answer.INPUT
chain for the protocol ping
uses, which is ICMP. Also, the target will need to be set to DROP
, in order to not send any rejection message. Therefore, option C is the correct iptables
command to use. The command in option A will set the policy to DROP
for all incoming packets that do not have a rule in the INPUT
chain, but that does not target ping
packets. Therefore, option A is a wrong answer. The command in option B will send a rejection message, which is not desired, so it is also an incorrect answer. The command in option D is attempting to delete a rule, not add one. Therefore, option D is a wrong choice. The command in option E is modifying the OUTPUT
chain instead of the INPUT
chain, which will affect outbound network packets. Thus, option E is an incorrect choice.sudo ufw status numbered
command will display the UFW firewall's ACL rules with their associated numbers. Therefore, option D is the correct answer. Option A is made up and thus is a wrong answer. Both options B and C will show any rules, but they will not include their numbers, so those options are incorrect answers. The UFW command in option E enables the firewall but does not display ACL rules, so it is an incorrect choice as well.ufw
command in option A will block all incoming and outgoing OpenSSH connections and not send a blocking (rejection) message. Thus, option A is the correct answer. There is no drop
argument in the ufw
command, so option B is a wrong answer. The command in option C would send a rejection message. Thus, it is a wrong choice. The command in option D will allow OpenSSH connections, and therefore it is an incorrect answer. There is no block
argument in the ufw
command, so option E is also an incorrect choice./etc/fail2ban/jail.conf
, but the configuration file for DenyHosts is not. Therefore, option D is an incorrect answer as well. DenyHosts can only work with TCP Wrappers, whereas Fail2Ban can work with iptables
, TCP Wrappers, firewalld
, and so on. Thus, option E is an incorrect choice.BlockThem
IPset. Thus, it is the correct answer. The commands in options A and B create the IPset and do not add new addresses to it. Therefore, those options are wrong answers. The command in option C will save the current IPset configuration to the IPset configuration file. While this is something Virginia should do after the new address is added, it is not the currently needed command. Thus, option C is a wrong answer. The command in option D adds an entire subnet of addresses to the IPset and not a single IP address. Thus it is an incorrect answer as well.nologin
utility as the default shell for a user account, users will receive a message upon successful login that they aren't allowed to access the system, so option E is correct. Biometrics, tokens, and Kerberos are all authentication methods that won't prevent the root user account from logging in, so options A, B, and C are all incorrect. Removing the root user account from the /etc/passwd
file removes the root user account from the system, which will break applications that require the root user account to run, so option D is incorrect./home
directory structure on Linux systems, so placing the /home
directory on a separate disk partition would separate user data from system data, making option B correct. The /usr
, /etc
, /sbin
, and /bin
directories all contain system data and not user data, so options A, C, D, and E are all incorrect.chroot
program restricts an application to a specific area within the virtual filesystem structure, so option D is correct. Blocking the application network port would prevent guests from connecting to the application, so option A is incorrect. Moving the application to a private port number wouldn't restrict access to directories, so option B is incorrect. Placing the application in an encrypted partition or on a separate partition wouldn't prevent the application from accessing data outside of the application, so options C and E are incorrect.chroot
utility restricts an application to a specific location in the virtual filesystem but doesn't encrypt files, so option B is incorrect. The auditd
utility creates detailed logs of system activity such as user file access but doesn't encrypt files or disks, so option D is incorrect. Both PKI and Kerberos are authentication methods and not disk encryption methods, so both options D and E are incorrect./etc/cron.deny
file is a list of user accounts prevented from scheduling jobs, so adding the user to that file would stop them from scheduling the job, making option C correct. The chroot
program restricts applications to a specific location in the virtual filesystem; it doesn't block users from scheduling jobs, so option A is incorrect. The nologin
program prevents user accounts from logging into the system, which is an extreme solution to the problem, so option B isn't a good solution. The /etc/hosts.deny
file blocks hosts from accessing the system and not users from scheduling jobs, so option D is incorrect. The /etc/motd
file displays a message to all users as they log into the system, but it won't block them from scheduling jobs, so option E is incorrect./etc/hosts.deny
file, preventing them from accessing the system, so option D is correct. Placing applications into a chroot jail prevents the application from accessing files outside of the jail filesystem but doesn't prevent the attacker from continuing to access a user account, so option A is incorrect. Adding the nologin
shell to the user account will prevent the attacker from accessing the user account but will also block the valid user from accessing the account, so option B is incorrect. Implementing two-factor authentication will help stop the attacker but isn't a quick solution, so option C is incorrect. Adding the user account to the /etc/cron.deny
file prevents the user account from scheduling jobs but won't stop the attacker from trying to log in as the user account, so option E is incorrect./etc/motd
file to display when users log in won't prevent them from using the FTP service, so option A is incorrect. Moving the FTP application to a different network port may temporarily solve the problem, but once users find the alternative ports, they can continue using FTP, so option B is incorrect. The /etc/hosts.deny
file contains IP addresses or hostnames of remote hosts to block, not user accounts, so option C is incorrect. The /etc/cron.deny
file blocks users from scheduling jobs, not accessing network applications, so option D is incorrect.iperf
, ping
, and traceroute
utilities will help test the network for high latency (slowness) in order to determine the cause. Thus, options A, B, and E are correct answers. The ip neigh
command is used to check the routing tables and is often employed in situations where a duplicate or incorrect MAC address is causing problems on a local network segment. Therefore, option C is a wrong answer. The dig
utility checks name server resolutions, not high latency. Thus, option D is also an incorrect choice.mtr
, tracepath
, and traceroute
utilities all allow Mr. Scott to view router packets traveling through certain network segments and isolate which routers may be dropping packets. Therefore, options A, D, and E are correct answers. The ifconfig
tool is for viewing and configuring network adapters. Therefore, option B is a wrong answer. The ethtool -s
command will show adapter statistics but not router information, and therefore option C is also an incorrect choice.nslookup
utility can be used along with the time
command to test new name servers to see if they are more efficient (faster). Thus, option D is the correct answer. Option A's dnsmasq
is caching-only name server software, so it is a wrong answer. The whois
utility performs queries of Whois servers, not name servers. Thus, option B is an incorrect answer. The nmap
utility is used for network mapping and analysis (or pentesting), and therefore, option C is a wrong choice. The ipset list
command displays the various IPsets on a system but is not involved with name resolution. Thus, option E is an incorrect choice.iostat
command displays I/O wait, which is a performance statistic showing the amount of time a processor must wait on disk I/O. Therefore, option A is the correct answer. The iopin
g utility is more for testing new disks on performance items such as disk I/O latency, seek rates, sequential speeds, and so on. Therefore, option B is a wrong answer. The du
and df
commands are useful for situations where disk space is an issue but do not provide I/O wait statistics. Therefore, options C and D are incorrect answers. The iotop
utility is helpful in locating an application or process causing high I/O but not CPU latency due to high I/O. Thus, option E is also an incorrect answer.deadline
I/O scheduler is good for situations where increased database I/O and overall reduced I/O latency are needed, and/or an SSD is employed, and/or a real-time application is in use. Therefore, option B is the correct answer. Option A is the I/O scheduler configuration file's name, and therefore it is a wrong answer. Option C is one of the subdirectories in the directory that contains the I/O scheduler configuration file, such as /sys/block/sdc/queue/
. Thus, option C is also an incorrect answer. The cfq
scheduler is best for situations where more balanced I/O handling is needed and/or the system has a multiprocessor. Therefore, option D is a wrong answer. The noop
I/O scheduler is good for situations where an SSD is employed but less CPU usage is needed. Therefore, option E is an incorrect choice.uptime
command displays CPU load averages in 1-, 5-, and 15-minute increments. Thus, options A, B, and D are correct answers and options C and E are incorrect choices.sar
utility is the best one for viewing a system's processor performance over time. It uses data stored by the sadc
program in the /var/log/sa/
directory, which contains up to a month's worth of data. Therefore, option C is the correct answer. The uptime
utility is handy to view processor performance, but sar
is a better one for viewing it over time. Thus, option A is a wrong answer. sysstat
is a package that provides the sar
utility, and therefore, option B is an incorrect answer. The /proc/cpuinfo
file contains detailed processor information, but it is not the best for viewing CPU performance. Thus, option D is also a wrong choice. The sysctl
utility is used to view or tweak kernel parameters. Therefore, option E is an incorrect choice.swapon -s
command will allow Gertie to view a swap space element's type, name, and priority. Therefore, option E is the correct answer. The vmstat
utility provides a lot of memory statistics, including disk I/O specific to swapping as well as total blocks in and blocks out to the device. However, it does not provide the information Gertie needs, so option A is a wrong answer. The free
command shows memory items such as free memory, used memory, and buffer/cache usage. Thus, option B is an incorrect answer. fstab
is not a command, but a file. This file is where swap partitions/files must have records in order for the swap space to remain persistent through reboots. Therefore, option C is a wrong choice. The swapoff
utility disengages a partition/file from swap space, and thus, option D is an incorrect choice.mkswap
and swapon
on the logical volume after it is extended, options A, B, C, and D are using those utilities on files or partitions, instead of logical volumes. Therefore, those options are incorrect choices.ps
command in Linux supports parameters that were supported by the legacy BSD and Unix ps
command, along with new options created by GNU, so options A, C, and D are correct. There are no Linux style options used by the ps
command, so option B is incorrect. The ps
command doesn't support numeric options, so option E is also incorrect.ps
command are identified by placing a single dash in front of the option, so option B is correct. The newer GNU options are identified by using a double dash, so option A is incorrect. The legacy BSD style options are identified by not placing anything in front of the option letter, so option C is incorrect. Unix style options still use letters, not decimal or hexadecimal numbers, so options D and E are both incorrect.ps
command displays only processes run by the current shell, so option D is correct. To display all processes running on a specific terminal, you need to add the -t
option, so option A is incorrect. To display all active processes, you must add the -A
option, so option B is incorrect. To display the sleeping processes, you need to use the -ef
option, so option C is incorrect. To display all processes run by the current user account, you need to add the -x
option, so option E is incorrect.top
command displays the currently running processes on the system and updates every 3 seconds, so option A is correct. The ps
command displays currently running processes but doesn't update in real time, so option B is incorrect. The lsof
command displays files currently opened by processes but not the processes themselves, so option C is incorrect. The pkill
and kill
commands are used to stop running processes, not display them, so options D and E are both incorrect.S
command displays the processes based on the cumulative CPU time for each process, so option E is correct. The l
command displays the processes based on the load average, so option A is incorrect. The F
command allows you to select the field used to sort the display, so option B is incorrect. The r
command reverses the sort order of the display, so option C is incorrect. The y
command highlights running tasks, so option D is incorrect.RES
column in the top
output displays the amount of physical memory used by the applications, so option B is correct. The VIRT
column displays the amount of virtual memory, not physical memory, so option A is incorrect. The SHR
column displays the amount of shared memory used, so option C is incorrect. The S
column displays the status of the application process, so option D is incorrect. The %MEM
column displays the percentage of physical memory the application is using but not the amount of physical memory, so option E is incorrect.nice
command allows you to specify the priority level for an application, so option C is correct. The renice
command allows you to change the priority level of an application that's already running, but not one that hasn't started yet, so option A is incorrect. The pkill
and kill
commands are used to stop running processes, not change their priority levels, so options B and D are incorrect. The pgrep
command displays the application processes matching a search term; it doesn't change the priority level of the processes, so option E is incorrect.renice
command allows you to change the priority level assigned to an application that's already running on the system, so option A is correct. The pkill
and kill
commands allow you to stop an application but not change the priority level, so options B and D are both incorrect. The nice
command allows you to start an application with a specified priority level but not change the priority level of an application that's already running, so option C is incorrect. The pgrep
command allows you to search for a running application based on a search term but not change the priority level of it, so option E is incorrect.pkill
command allows you to send a HUP
signal to a running process based on a search term for the process name, so option B is correct. The renice
command allows you to change the priority level of an application that's already running but not stop it, so option A is incorrect. The nice
command allows you to start an application at a specified priority level but not stop an application that's already running, so option C is incorrect. The kill
command allows you to stop an application that's running, but you need to use the process ID number and not the name, so option D is incorrect. The pgrep
command allows you to search for running applications based on their name but not stop them, so option E is incorrect.kill
command allows you to stop an application that's already running by specifying its process ID, so option D is correct. The renice
command allows you to change the priority level of an application but not stop it, so option A is incorrect. The pkill
command allows you to stop an application, but by specifying its process name and not its process ID, so option B is incorrect. The nice
command allows you to start an application using a specified priority level but not stop an application, so option C is incorrect. The pgrep
command allows you to display running applications based on a search term for the application name but not stop them, so option E is incorrect.last
command is not helpful in this scenario, unless you think Irene is confused, so option D is an incorrect choice as well.-vvv
option on to his ssh
command. This will provide a great deal of information that will assist you as you track down the problem. Therefore, option B is the correct answer. The /etc/ssh/sshd_config
configuration file is on the server side, and Vincent cannot reach the system, so option A is the wrong answer. The -X
option will only help if your system is forwarding X11 GUI servers over the network, so option C is an incorrect answer. If Vincent is using token-based authentication via ssh
, then this will need to be checked, but it's not the first item to address. Thus, option D is a wrong choice. The config
file may need to be checked, but it's not the first item to address, so option E is an incorrect choice as well./var/log/secure
and /var/log/lastlog
using the lastlog
command. Therefore, options D and E are the correct answers. Since auditd
is not employed, the file in option A is not available and is a wrong answer. Since SELinux is not used, the file in option B is also an incorrect answer. This system, Rocky Linux, is a Red Hat–based system and not Debian, so the /var/log/auth
file is not available. Thus option C is also an incorrect choice.wheel
group and add execute (x
) to the shell script file's permissions. Thus, options A and D are the correct answers. Option B will do nothing for this situation and is a wrong answer. Adding write (w
) to the group permissions will not allow her (or the wheel
group members) to execute the file. Thus, option C is a wrong choice. Actions need to take place, so option E is incorrect./home/miles
, the other section must have the execute (x
) permission. Therefore, option B is the correct answer. You do not know Miles's home directory configuration, so you cannot assume it is /home/miles
. Thus, option A is the wrong answer. The write (w
) and read (r
) permissions don't allow a user to change his present working directory to this directory. Therefore, options C and D are incorrect answers. The dash (-
) in a file permission listing is not a permission but instead shows the absence of a permission. Thus, option E is also an incorrect choice.lsattr
command used on the file will display whether or not the immutable bit is set. If this bit is set, the user cannot delete the file until it is removed. Therefore, option E is the correct answer. The chown
command changes a file's ownership, and thus option A is the wrong answer. The chattr
command can add or remove certain file attributes, such as the immutable bit, but is not helpful at this point, so option B is an incorrect answer. The chmod
utility changes file permissions (modes), but it does not help in this situation, so option C is a wrong choice. The umask
command displays or sets what permissions are removed from default permissions when a file or directory is created. This is not helpful here, so option D is an incorrect choice.export EDITOR='vim'
line is put in her ~/.profile
file, the default editor will be set to the vim
editor for Melissa. It will also stay set when she enters a subshell. Thus, option D is the correct answer. If option A or B was completed, then everyone on the system would have the vim
editor as their default editor. Therefore, options A and B are incorrect answers. Option C would set the vim
editor as Melissa's default editor, but it would not be set when she entered a subshell due to the missing export
command. Thus, option C is also an incorrect answer. The . bash.bashrc
file does not reside in the user's local directory (it is located in the /etc
directory) and is also not a hidden file, so option E is an incorrect choice.echo $SHELL
command will show Mark his current shell. Though it could be a modified environment variable, this will help to determine if his default shell has been changed. Thus, option B is a correct answer. The sudo grep tcsh$ /etc/passwd
command will display any /etc/passwd
file records that have /bin/tcsh
as their default shell, including Mark's. Thus, option C is a correct answer too. The sudo getent passwd MW2015
command will show Mark's account's password file setting, including its default shell. Therefore, option E is also a correct answer. The option A command will display the settings in the profile environment configuration file, but since Mark is the only one experiencing the problem, the SHELL
environment variable is not set with this method. Thus, option A is a wrong answer. The command in option D will show the shadow file records and not the password file records. Therefore, option D is an incorrect choice./proc/ioports
file to track the I/O ports used by the installed PCI boards on the system, so option A is correct. The kernel uses the /proc/interrupts
and /proc/dma
files to track interrupts and the DMA channel, not I/O ports, so options B and E are incorrect. The /sys
directory contains files used to track kernel, module, and system features, not I/O ports, so option C is incorrect. The /dev
directory contains files used to transfer data to and from devices, not track their I/O ports, so option D is incorrect./dev
directory for each device on the Linux system. These files are used to send data to the device and read data from the device. Thus, option D is correct. The /sys
and /proc
directories are used by the kernel to display system information, not transfer data, so options A and B are incorrect. The /etc
directory is used for configuration files, not for transferring data, so option C is incorrect. The /dev/mapper
directory is used by virtual systems such as LVM and LUKS to create virtual files that indirectly interface with devices through another application, not directly, so option E is incorrect./dev/mapper
directory to create virtual files that interface with applications that manipulate data on a virtual LVM volume before being sent to a physical hard drive device, so option B is correct. The /dev
directory contains the physical device files, not virtual files, so option A is incorrect. The kernel uses the /proc
and /sys
directories to display kernel and system information, not virtual files for LVM volumes, so options C and D are incorrect. The /etc
directory contains configuration files for applications, not LVM volumes, so option E is incorrect.lsdev
command displays all the hardware information about all the devices connected to the system, so option A is correct. The lsblk
command only displays information on block devices, so option B is incorrect. The lspci
command only displays information about PCI devices, so option C is incorrect. The lsusb
command only displays information about USB devices, so option D is incorrect. The dmesg
command displays messages from the kernel ring buffer, not information about the current devices, so option E is incorrect.dmesg
command displays the kernel event messages contained in the kernel ring buffer, so option E is correct. The lsdev
command displays hardware information about devices, but not messages from the kernel, so option A is incorrect. The lsblk
command only displays information about block devices, not kernel event messages, so option B is incorrect. The lspci
command only displays information about PCI devices, not kernel event messages, so option C is incorrect. The lsusb
command only displays information about USB devices, not kernel event messages, so option D is incorrect.X.org
and Wayland software packages implement the X Windows graphical system for Linux, so options A and C are correct. The CUPS software package implements PostScript printing for Linux, not X Windows graphical systems, so option B is incorrect. X11 is an X Windows standard but not a software package, so option D is incorrect. The udev
program is used to detect hot-pluggable devices, not implement the X Windows graphical system, so option E is incorrect.X.org
and Wayland software packages are used to implement the X Windows graphical system in Linux, not interface with printers, so options A and C are incorrect. X11 is a standard for X Windows, not a software package for printers, so option D is incorrect. The udev
program detects hot-pluggable devices but doesn't interact directly with the printers, so option E is incorrect.udev
program runs in the background and monitors the kernel ring buffer for event messages from new devices, so option E is correct. The X.org
and Wayland software packages implement the X Windows graphical system but don't listen for new devices, so options A and C are incorrect. The CUPS package interfaces with printers on the Linux system and doesn't listen for new devices, so option B is incorrect. X11 is a standard for X Windows and not a software package that listens for new devices, so option D is incorrect.udevadm
program allows you to send control messages to the udev
application running in background, signaling it to reload the rules defined in the /etc/udev/rules.d
directory, so option A is correct. The udev
application can't direct itself to reload the rules, so option B is incorrect. The lsusb
, lspci
, and lsdev
programs are used for displaying hardware information for the system, not for directing the udev
program to reload defined rules, so options C, D, and E are all incorrect.pvscan
utility is used for physical volumes being used for a logical volume's volume group. Therefore, option B is a wrong answer. The hdparm
and smartctl
commands in options D and E are employed for checking and resetting power management configurations on a SATA device. Thus, they are incorrect choices.sudo apt-get check
command will check for such a thing. Thus, option E is the correct answer. The commands in options A and B will clean up the repository database and any temporary download files but not help to troubleshoot this issue. Therefore, options A and B are wrong answers. The command in option C shows library files used by the Apache service, but it does not help troubleshoot the problem and is therefore an incorrect answer. Option D's command checks for broken dependencies, but on a Red Hat–based system, and thus it is an incorrect choice.sealert
utility is used to check the audit log file for SELinux context violations. Therefore, the issue here revolves around SELinux. The ls -Z
command will allow Mary to view the flash.txt
file's SELinux context to determine if it needs to have it changed. Thus, option B is the correct answer. The option A command will not show the file's SELinux context and is therefore a wrong answer. While the flash.txt
directory might have a context problem, the ls -l
command will not show it, and thus option C is a wrong choice as well. Option D's setroubleshoot
is a package and not a command, so it is a wrong answer. Option E's restorecon
will fix SELinux labels, which may be used in the repair process but not in troubleshooting, so it is an incorrect choice./etc/services
file needs checking. That information is critical for reviewing server- and client-side firewall ACLs. Thus, option D is a correct answer too. It is a good idea to view the firewall log entries because they may point to the exact cause of the problem or provide valuable information. Therefore, option E is a right choice. The firewall-cmd
command is specific only to those systems that employ the firewalld
firewall. Therefore, option C is the only incorrect choice./dev/ttyS#
device files. To find the right number (#), use the dmesg
command to start the troubleshooting process. Thus, option B is the correct answer. Since a serial port is not represented by files named /dev/COM#
, both options A and C are wrong answers. The setserial
command is used after you determined the appropriate filename for the serial device, so it is not the first step and option D is an incorrect answer. The cat /proc/interrupts
command is performed after you find the correct IRQ via the setserial
command, so option E is an incorrect choice as well./etc/cups/printers.conf
file instead of the /etc/printcap
file, so option A is a wrong answer. The lpinfo -m
command allows you to view available printer drivers, not USB ports, so option B is an incorrect choice as well.#!
character combination defines the shebang, which tells the Linux shell what shell to use to run the shell script code, so option B is correct. The >>
character combination appends the output of a command to a file, so option A is incorrect. The |
character pipes the output of a command to another command, so option C is incorrect. The >
character redirects the output of a command to a new file or overwrites an existing file, so option D is incorrect. The 2>
character combination redirects error messages from a command to a file, so option E is incorrect.>
character redirects all of the output from a command to a new file, or overwrites an existing file, so option D is correct. The >>
character combination appends all of the output from a command to an existing file, so option A is incorrect. The #!
combination defines the shell to use, so option B is incorrect. The |
character pipes output from one command to another command, so option C is incorrect. The 2>
character combination redirects only error messages from a command to a new file, not all of the output, so option E is incorrect.u+x chmod
permission assigns execute permissions to the file owner so that you can run the file at the command prompt, which makes option C correct. The 644
octal permission assigns only read and write permissions to the file owner, not execute permissions, so option A is incorrect. The u+r
permission assigns read permissions, not execute permissions, so option B is incorrect. The u+w
permission assigns only write permissions and not execute permissions, so option D is incorrect. The u=wr
permission assigns both read and write permissions but not execute permissions to the file owner, so option E is incorrect.$USER
environment variable contains the text username of the user account that started the shell, so option A is correct. The $UID
environment variable contains the numeric user ID, not the text username, so option B is incorrect. The $HOME
environment variable contains the home directory location of the user account, not the username, so option C is incorrect. The $BASH
environment variable contains the location of the Bash shell executable file, not the username of the user who started the shell, so option D is incorrect. The $1
variable is a positional variable, not an environment variable. It's used to retrieve data from the command-line command that launched the shell, not to identify the user who started the shell, so option E is incorrect.-f
file
test checks if the specified object exists, and if it's a file, so option B is correct. The -e
file
test checks if the object exists, not the object type, so option A is incorrect. The -d
file
test checks if the object exists but is a directory, not a file, so option C is incorrect. The -x
file
test checks if the current user account has execute permissions for the file, not that the object exists and is a file, so option D is incorrect. The -w
file
test checks if the current user account has write permissions for the file, not that the object exists and is a file, so option E is incorrect.|
) pipes the output of one command to the input of another command, so option C is correct. The >>
character combination appends the output of a command to an existing file, not to another command, so option A is incorrect. The shebang (#!
) is used to identify the shell to use to run the script, not to redirect output from a command to another command, so option B is incorrect. The >
character redirects the output of a command to a new file, not to another command, so option D is incorrect. The 2>
character combination redirects the error messages from a command to a new file, not to another command, so option E is incorrect.exit
command allows us to return a specific error status when the shell script exits, so option D is correct. The #!
shebang defines the shell to use to run the shell script, not the exit status, so option A is incorrect. The $?
character combination displays the exit status from the last command; it doesn't return a specific exit status, so option B is incorrect. The $1
variable contains the first command-line parameter used when the shell script is launched from the command line; it doesn't set the exit status for the shell script, so option C is incorrect. The while
command allows us to iterate through a set of commands until a specific condition is met; it doesn't return a specific exit status when the shell exits, so option E is incorrect.$()
command assigns the output of a command to a specified variable in the shell script, so option E is correct. The >
character redirects the output of a command to a file, not to a variable, so option A is incorrect. The >>
character combination appends the output of a command to an existing file, not to a variable, so option B is incorrect. The $[]
command performs integer mathematical operations in the Bash shell, so option C is incorrect. The |
character redirects the output of a command to another command, not to a variable, so option D is incorrect.$[]
command performs simple integer mathematical operations in the Bash shell, so option C is correct. The >
character redirects the output of a command to a new file, so option A is incorrect. The >>
character combination appends the output of a command to an existing file, so option B is incorrect. The |
character redirects the output of a command to another command, so option D is incorrect. The $()
command redirects the output of a command to a variable in the shell script, so option E is incorrect.&
) tells the shell to start the command in background mode from the console session, so option B is correct. The greater-than sign (>) redirects the output from the command to a file, so option A is incorrect. The pipe symbol (|
) redirects the output from the command to another command, so option C is incorrect. The double greater-than sign (>>) appends the output from the command to a file, so option D is incorrect. The nohup
command disconnects the session from the console session, so option E is incorrect.nohup
command disconnects the shell script from the current console session, so option E is correct. The greater-than sign (>) redirects the output from the command to a file, so option A is incorrect. The ampersand sign (&
) runs the shell script in background mode, so option B is incorrect. The pipe symbol (|
) redirects the output from the command to another command, so option C is incorrect. The double greater-than symbol (>>) appends the output from the command to a file, so option D is incorrect.nohup
command disconnects the job from the console session, so you can't stop it from the console with a key command, making option A incorrect. Starting a job with the ampersand (&
) command places the job in background mode but doesn't allow you to stop the job from running, so option B is incorrect. The pipe symbol redirects the output from a shell script to another command, so option D is incorrect. The kill
command will stop a running shell script, but if the shell script is running in your console session, you won't be able to submit the kill
command from the command prompt, so option E is incorrect.nohup
command disconnects a job from the console session but doesn't pause the job, so option C is incorrect. The ampersand sign (&
) runs a job in background mode in the console session, so option D is incorrect. The fg
command resumes a stopped job in foreground mode, so option E is incorrect.jobs
command, there will be a plus sign next to the default job number, so option C is correct. The minus sign next to a job number indicates the job next in line to become the default job, so option D is incorrect. Neither the PID nor the job number indicates the default job, so options A and B are both incorrect. The ps
command lists the running jobs but doesn't indicate the default job in a console session, so option E is incorrect.fg
command allows you to change a currently running or stopped job to run in foreground mode on the current console session, so option B is correct. The bg
command changes a currently running or stopped job to run in background mode, so option A is incorrect. The nohup
command disconnects a job from the console session, so option C is incorrect. The ampersand sign (&
) places a job in background mode, not foreground mode, so option D is incorrect. The at
command runs a job in background mode at a specific time, so option E is incorrect.at
command allows you to schedule a job to run at a specific time, so option C is correct. The nohup
command disconnects a job from the console session, so option A is incorrect. The ampersand sign (&
) runs a job in background mode, so option B is incorrect. The pipe symbol (|
) and the greater-than symbol redirect the job output to either a command or a file, so options D and E are both incorrect.cron
program checks the cron tables for each user account and runs any scheduled jobs automatically, so option D is correct. The at
command only runs a specified command once at a scheduled time, so option A is incorrect. The nohup
and ampersand (&
) commands do not schedule jobs to run, so both options B and C are incorrect. The atq
command displays the jobs already scheduled to run from the at
command, so option E is incorrect.crontab
command allows you to list or edit the cron table for your own user account, so option C is correct. The cron
command is what reads the cron tables for each user account and runs the specified jobs; it doesn't list the jobs, so option A is incorrect. The at
command allows you to schedule a job to run at a specific time, so option B is incorrect. The jobs
command allows you to view the currently running or stopped jobs in your console session, so option D is incorrect. The nohup
command disconnects the job from the console session, so option E is incorrect..git/objects/
directory. Thus, option A is an incorrect choice..git/
directory in her working directory, via the git init
command. Therefore, option D is the correct answer. The mkdir
command is employed to create the working directory, which is already done, so option A is a wrong answer. The git config --list
command shows configuration data, which should be done after the .git/
directory is initialized, so option B is a wrong choice. While Natasha could set up her GitHub repository now, it is not the best next step, so option C is a wrong answer. Starting to create program files is an incorrect choice since Natasha is still setting up her Git environment. Therefore, option E is incorrect.--global
option when setting his Git configuration options, the information is stored in the global ~/.gitconfig
file. Therefore, option B is the correct answer. This Git configuration information is not stored on GitHub, and GitHub may not even be employed as the remote repository in this case, so option A is a wrong answer. The working directory's .git/config
file is the local file, not the global one, so option C is a wrong choice. The .git/index
file and .git/objects
directory do not store this type of data, so options D and E are incorrect choices.git add GreenMass.sh
command. Therefore, option A is the correct answer. The git init
command is used to initialize the .git/
directory in the working directory and is part of setting up the Git environment, so option B is a wrong answer. The script cannot yet be committed to the local repository because it has not been added to the staging area. Thus, option C is an incorrect choice. The git log
command shows the commit history and is not appropriate at this point, so option D is a wrong answer. The script cannot be committed to the remote repository until it is committed to the local repository. Therefore, option E is an incorrect choice.git add .
command, which will add all the files within the working directory to the staging area (index). To stay efficient, she should create a .gitignore
file in the working directory and add the names of the three files that she wishes to keep out of the index to that file. This will prevent them from being added. Therefore, option D is the correct answer. While Natasha could move the three files out of her working directory, that is a sloppy and inefficient choice, so option A is a wrong answer. She also could add the 22 files individually to the index, but that too is very inefficient, as is creating a new working directory for the three files. Thus, options B and C are incorrect answers. Temporarily deleting the three files would force Natasha to re-create them after the other files are added to the index. This too is sloppy, and therefore option E is an incorrect choice.remote add origin
URL
command is used to configure the remote repository's address (URL), which Natasha has already accomplished. Thus, option E is an incorrect choice.git checkout testing
command will allow you to switch to a new Git branch called testing
. Thus, option E is the correct answer. The git branch testing
command creates a new branch called testing
instead of switching to it. Thus, option A is a wrong answer. The command in option B allows you to view the names of any files managed by the testing
branch, so it is an incorrect answer. The git branch
command shows you the current branches within this project and designates which one is current via an asterisk, but it does not allow you to switch branches. Thus, option C is an incorrect answer. The command in option D will perform a commit to the local repository and add a comment of testing
to the log file. Therefore, option D is also an incorrect choice.git merge report
command will merge the report
branch into the master
branch as desired, so option B is the correct answer. The git merge master
command will attempt to merge the master
branch into another branch, but since Tony is already in the master
branch, this will not work (and is not desired), so option A is a wrong answer. The rebase
arguments will attempt to perform a rebase instead of a merge. Thus, options C and D are incorrect answers. The git checkout master
command was already used by Tony to reach the master branch, and thus option E is an incorrect choice.tar
file for distribution, so option C is correct. The Open Virtualization Format (OVF) format defines several separate files for storing configuration values, not a single file, so option D is incorrect. XML, JSON, and YAML are all configuration file formats and not methods to bundle the configuration files, so options A, B, and E are all incorrect.tar
file doesn't ensure that the required system library will be present on all of the customer workstations, so option E is incorrect.libvert
library software collection and are therefore correct answers. This software collection does not provide a complete hypervisor application (though many hypervisors incorporate it), so option B is a wrong answer. Also the libvert
library does not provide an anaconda file. Thus, option D is also an incorrect choice.virsh
and virt-install
utilities are ones that Carol can incorporate into her Bash shell script for managing her virtual machines. Therefore, options A and D are correct answers. virtinst
is the name of a package file, which provides utilities such as virsh
, and thus, option B is a wrong answer. Option C, virt-manage
, is a made-up utility, making option C an incorrect answer. setvcpus
is an argument you can use with the virsh
utility, as opposed to a utility itself, so option E is an incorrect choice.18.117.145.173