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Correct CHOICE is (B) False

The explanation is: tar command cannot use the standard input to obtain its FILE list. It accepts only file and directory NAME as arguments.

Right answer is (d) -x

Explanation: FILES can be restored USING -x option with the tar command. When no file or DIRECTORY is specified it restores all the files from the BACKUP device.

Right answer is (a) True

The BEST EXPLANATION: -t option ALIKE cpio is also used with tar command for displaying the archive. For EXAMPLE,

Correct CHOICE is (b) -C

Explanation: The tar (tape archive) command is more powerful than cpio command. For creating a backup using tar, we have to use the -c OPTION. For example,

The correct OPTION is (d) -i and -o

To explain: cpio COMMAND uses two key OPTIONS, -o (output) and -i (input). The -o option is USED for backing up files while the -i option is used for restoring files.

Correct answer is (d) format and fdformat

For explanation: Before backing up data to a FLOPPY, we may need to format it. For this PURPOSE, either format or fdformat command is USED (whichever is SUPPORTED by your system).

The correct OPTION is (d) cpio

Explanation: As a system administrator, you are RESPONSIBLE for creating a BACKUP of the data which resides on your system. For this PURPOSE, there are mainly two backup PROGRAMS which are extensively used i.e. cpio and tar. The cpio command copies files to and from a backup device.

The correct choice is (d) dd

To EXPLAIN I would say: dd (disk jump) COMMAND can be used in copying FILES systems, but is majorly used for copying media (floppies and TAPES).

The CORRECT CHOICE is (c) device driver

The explanation is: The set of routines needed to operate a specific device is known as a device driver. Whenever a PARTICULAR device is accessed, the kernel calls the correct device driver and PASSES some PARAMETERS to it.

Right answer is (c) /dev

For explanation: A DEVICE file is a file which is BUILT into the kernel for each and every device of the system. All the device files are stored in /dev or in its SUBDIRECTORIES. To view the LIST of device files on your system, use the following command:

Correct choice is (a) True

For explanation: Most of the DYNAMIC space in the system is consumed by users, their DIRECTORIES and files. We can use the following command if we WANT to know the disk space consumed by each USER.

The CORRECT ANSWER is (d) -s

To elaborate: If we use the du command, then by default it displays the usage of each subdirectory of its ARGUMENT along with a summary at the end. If we WANT to display the only summary then we can use -s option with du command. For example,

Correct ANSWER is (d) -k

To explain I would say: The df (DISK free) command reports the amount of space available for each FILE system separately. -k option is used with df command for DISPLAYING the total amount of disk space in the file system in TERMS of Kilobytes.

Right answer is (a) DU

For explanation: Sometimes, we may need to find out the consumption of a specific directory rather than an ENTIRE FILE system. For this purpose, du command is used. This command REPORTS usage by RECURSIVE examination of the directory structure.

Right option is (C) -t

Best explanation: The -t (total) option when used with df COMMAND DISPLAYS free SPACE on each file system as WELL as the total amount of disk space in the file system.

The correct choice is (d) shutdown -y -g0 -i6

To explain I would SAY: -y option is used with shutdown command for shutting the system IMMEDIATELY. Similarly, we can use the shutdown command to TURN the MACHINE off in various ways. To shut down and reboot the system, use the following command:

Right option is (a) -g

Explanation: -g option is used with SHUTDOWN COMMAND to override the default WAITING time (ONE minute). For EXAMPLE,

The CORRECT answer is (a) True

Easiest EXPLANATION: The system administrator is also responsible for SHUTTING down the system. For this purpose, shutdown COMMAND is USED. This command performs various activities before shutting the system.

Right answer is (a) True

Easiest EXPLANATION: We can remove users from the system USING the userdel command. To remove a PARTICULAR user from the system, use the FOLLOWING command:

Right CHOICE is (d) usermod

For EXPLANATION: usermod command is used for modifying some parameters set with useradd. For EXAMPLE, sometimes users need to change their login shell, to do so root user will invoke the FOLLOWING command:

Right option is (d) encrypted PASSWORD

Best EXPLANATION: The password encryption itself is stored in /etc/shadow while there are SEVEN FIELDS in /etc/passwd namely:

•Username

•Password

•UID

•GID

•GCOS

•HOME directory

•Login SHELL

Correct option is (a) etc/passwd

Easy explanation: All the USER INFORMATION except the PASSWORD encryption is stored in /etc/passwd. The encryption itself is stored in /etc/shadow. There are seven FIELDS in /etc/passwd.

The CORRECT option is (b) useradd

Explanation: The useradd COMMAND is used to add new users to the system. Before USING this command the super user should provide all the PARAMETERS related to the user in the command line itself. For example,

Right option is (a) True

Explanation: The sticky bit (also called the saved text bit) when applied to a REGULAR file ensures that the text image of the program with the bit set is permanently kept in the swap area. The sticky bit also comes with a security FEATURE when applied to directories. To apply the sticky bit to a DIRECTORY superuser can use 1 as the additional bit with chmod in the following manner:

The correct CHOICE is (c) pswd

Explanation: The pswd command prompts for EXISTING PASSWORD when this command is used by a non-privileged USER but when the same command is used by the superuser it behaves much leniently and doesn’t ask for the old password this TIME. For example,

Right option is (a) True

Best explanation: The access to the use of at and BATCH is restricted and controlled by the files at.allow and at.deny. If at.allow is present, only those users which are listed in this FILE can use at and batch. If this file is not present then the SYSTEM checks at.deny for users who are blocked from using these commands. If NEITHER file is present, only the administrator can invoke at and batch.

Right option is (C) DATE

For EXPLANATION I would say: date command is USED by users for displaying the system date. Same command is used by the system administrator to change/set the system date. The argument is an eight-character string of the form MMDDhhmm. For example,

Right answer is (d) WALL

Explanation: The wall COMMAND can be used by the administrator to address all users SIMULTANEOUSLY. For EXAMPLE,

Right CHOICE is (c) ctrl-d

To EXPLAIN I would SAY: The administrator can CREATE a simulated environment USING su – for any user. This mode runs a separate sub-shell and is terminated using ctrl-d or exit.

The correct CHOICE is (b) su –

The best explanation: The administrator can create a simulated environment using su – for any USER. This COMMAND CREATES the user’s environment without taking the login-password route. For example,

The correct option is (b) su

For explanation: Any user can acquire the STATUS of superuser by using the su COMMAND. The only condition that needs to be FULFILLED here is, he/she must be aware of the ROOT password. For EXAMPLE,

The correct option is (a) True

Explanation: Since we know that the SUPERUSER has to CONSTANTLY navigate through the file system, it MAY happen that he/she unintentionally EXECUTE the SCRIPTS or programs written by other users. That’s why the PATH for a superuser doesn’t include the current directory.

Correct option is (C) #

The best I can explain: The PROMPT of the root user is # whereas the prompt for NORMAL USERS or non-privileged users is % or $.

The correct option is (d) MASTER and super user

Explanation: The system administrator has ACCESS to huge powers. This entrusted PERSON is ALSO known as the root user or superuser.

Right choice is (a) root

Best EXPLANATION: UNIX provides a special login NAME for system administrator i.e. root. This account doesn’t need to be created SEPARATELY but comes with EVERY system. The password for the root user is set at the time of installation.

Right answer is (d) -s

Explanation: test can ALSO be used for performing VARIOUS file tests like checking whether the file is a regular file, or is it readable, WRITABLE or executable. To CHECK whether the file exists and has the size greater than zero, we have to use -s option with test. For EXAMPLE,

Correct answer is (a) True

For explanation: shift statement is USED for shifting the positional parameters to its IMMEDIATE lower ones. Every time we use shift, the LEFTMOST variable GETS lost; s it should be saved in a variable before using shift.

Correct option is (c) COMPARE two files

The explanation: TEST works in THREE ways:

•compare two numbers

•compare two strings

•check a FILE’s attributes

The correct answer is (c) $0 was USED in the script

For EXPLANATION I WOULD say: A shell script will stop running when we change its name if we’d used the POSITIONAL PARAMETER $0 in it as $0 contains the name of the script file.

Right choice is (d) x10$

Easiest explanation: Since x CONTAINS the value 10, and $ symbol is USED with any variable for DISPLAYING its value. So $x will display 10. Hence the OUTPUT will be x10$.