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Correct choice is (a) .

The best I can EXPLAIN: To change PERMISSIONS for hidden files, use the (.) SYMBOL with chmod command.

The CORRECT option is (a) True

Best explanation: UNIX provides a special privilege for the system ADMINISTRATOR to change both the owner and group using CHOWN command only. The syntax REQUIRES two arguments to be separated by a (:). For example,

The correct choice is (a) -R

For explanation: Like chmod, chown and CHGRP use the -R OPTION to perform their operations in a recursive manner.

Right CHOICE is (c) chgrp

The BEST I can EXPLAIN: A user can CHANGE the group owner of a file but only to that group to which he belongs. A user can belong to more than one group and the one shown in /etc/psswd is the user’s MAIN group.

The correct ANSWER is (a) Yes

The explanation is: The file having permission set as 000 is useless i.e. it is not readable, writable or executable. But we can delete the file USING directory PERMISSIONS. If the directory has write permission, we can easily add or remove a file from it.

The correct option is (b) No

The best EXPLANATION: Since we have only read permissions for the DIRECTORY and the directory permissions do not ALLOW us to add or REMOVE a file from it we cannot delete a file no matter what is the permission set of that file.

The correct choice is (a) True

The explanation: The EXPRESSION used by chmod in an absolute manner is a string of three octal numbers (BASE 8).A set of 3 bits represent a single octal DIGIT.

->Read permission –4 (100 in octal)

->Write permission –2(010 in octal)

->Execute permission –1(001 in octal)

For each category, we add up these numbers. For example, if we have to set read and write permission then an octal number will be 110 (4+2).

The correct option is (b) chmodgo-w file01

For explanation I WOULD SAY: To remove a certain permission from a category of users we use (-) symbol. So above COMMAND will remove write permission from GROUP and others.

The correct CHOICE is (a) a

For explanation I would say: UNIX offers a SHORTHAND SYMBOL ‘a’ (all) that acts as a synonym for the ‘ugo’ string which represents all the categories of users.

Correct answer is (c) +

To ELABORATE: To ASSIGN and REMOVE permissions from a file, (+) and (-) symbols are used RESPECTIVELY.

‘+’ symbol will assign a permission

‘-‘ symbol will remove a permission

Correct choice is (a) ‘u’ and ‘g’

To explain I WOULD say: Each character SPECIFIES a particular category of users as FOLLOWS:

‘u’ STANDS for a USER,

‘g’ for ‘group’

‘o’ for ‘others’.

The correct option is (d) 3

For explanation: chmod command TAKES an EXPRESSION as its arguments which comprises of some LETTERS and SYMBOLS. The expression comprises three components:-

->User category (user, group, others)

->The operation to be performed (assign or remove a permission)

->Type of permission (read, write, EXECUTE).

Correct OPTION is (B) 2

Explanation: chmod command can be USED in two manners i.e. relative (changes are specified to the CURRENT PERMISSIONS) and absolute (final permissions are specified).

Right OPTION is (a) True

The explanation: We can change permissions of MULTIPLE FILES by USING chmod command once. To change permissions of multiple files simultaneously just use the chmod command with multiple filenames as arguments.

The correct option is (b) No

To explain I would say: The FILE owner cannot edit the file because the owner’s permission overrides the group’s permission. In other words, the PRIORITY of owner’s permission is GREATER than group’s permission.

Correct answer is (a) chmod

Best EXPLANATION: The chmod (change mode) command is used to change the PERMISSIONS of files. This command can only be RUN by the owner of the FILE or by the super USER.

Correct OPTION is (b) rwxrwxrwx

The BEST I can explain: The DEFAULT PERMISSION set for an ordinary file is rwxrwxrwx i.e. it is READABLE, writable, executable by owner, group members and others.

Right answer is (d) permission to search or navigate through the directory

Best EXPLANATION: Executing a directory does not make any sense, execute permission simply means that a USER can “pass through” the directory while searching for subdirectories. When we USE pathname with any command we should have execute permission for each of the directories involved in the COMPLETE pathname. For example,

Correct choice is (b) False

To explain I WOULD say: The term ‘WRITE-protected’ has a LIMITED meaning in the UNIX file system. A file which is write protected cannot be written, but it can be REMOVED if the DIRECTORY has to write permission.

Correct OPTION is (d) we can ADD or remove FILES to it

The explanation is: The write permission of a DIRECTORY does not imply that we can write to the directory. Only kernel is allowed to do that. It simply means that we can create or remove files from the directory.

The CORRECT ANSWER is (a) True

Explanation: Since the second and THIRD group of permissions of a FILE are r–and — respectively. So the file is only readable and that too, only by the MEMBERS of the group to which the file belongs.

The CORRECT choice is (a) group of users who can access the file

The best I can explain: When the system ADMINISTRATOR creates a user account, he assigns the user two parameters; UID (user ID) and GID (group ID). Group id denotes the group to which the user belongs.

In SIMPLE WORDS, group ownership defines the group to which the file is accessible.

Correct answer is (a) True

Explanation: In most cases, the user which creates the file is REGARDED as owner of the file. The owner of the file can create, DELETE or edit the file or he can change the permissions ASSOCIATED with it.

Correct CHOICE is (d) –

Explanation: ( – ) is used to indicate the ABSENCE of a single or set of permissions of a file. For example, if a file has all the three permissions for owner but is only READABLE by group members and others, then the set of permissions WOULD be,

The correct OPTION is (a) r,w,x

For EXPLANATION: A file can have THREE types of permissions; read, WRITE and EXECUTE which is represented by characters r, w and x respectively.

The correct option is (B) –

For explanation: When LS COMMAND is used with -l option its displays attributes of a file in the multi-columnar FORM. The first column defines the file types and permissions associated with a file. If the permissions are preceded by a (-), then it is an ordinary file OTHERWISE it is a directory.

Correct option is (c) 3

To explain: In UNIX system, a file can have three TYPES of PERMISSIONS -read, write and execute. Read permission means that the file is readable. Write permission means that the file can be EDITED while executing permission (for a DIRECTORY) means that we can “pass through” the directory file for searching subdirectories.

The correct choice is (C) 2048

Explanation: SINE files are written to the disk in terms of BLOCK SIZE, the size consumed by the file vary from the original size of the file. Suppose, if a file size is 800 bytes but the block size on the system is 1024 bytes, then that file will consume 1024 bytes on diskspace i.e. 1 block.

Correct answer is (B) False

Easy explanation: Directory attributes are of major concern as compared to FILE attributes when PERFORMING any operation on file system because files are a part of directory or we can say that files are stored under the directory in the directory TREE. So if directory attributes does not ALLOW us to perform a particular operation on the directory than that operation can never be performed on the file which is stored inside that directory.

Correct choice is (d) -d

For explanation: LS command when combined with -d OPTION DISPLAYS the attributes of a directory RATHER than its contents.

The correct CHOICE is (a) True

Explanation: Soft linked FILES are PROVIDED with a separate inode number each of which points to the original FILE location.

Correct OPTION is (a) True

Easy explanation: Hard linked FILES are provided with the same INODE number as the ORIGINAL file so they refer to the same physical LOCATION of the file.

Correct answer is (b) 2

For explanation I would say: There are basically two types of links; HARD LINK and soft links.

Right option is (d) word count of file

To elaborate: When -l option is used with ls command it simply displays seven attributes of a file which are file type and permissions, LINKS, OWNERSHIP, group ownership, file SIZE, last MODIFICATION time, filename.

The CORRECT option is (C) ls

The EXPLANATION is: ls command is used for listing the attributes of a file or directory. ls command when used with -L displays all the seven attributes of a file.

Right ANSWER is (a) True

Best explanation: An attribute DEFINES the PROPERTY of an object. In UNIX, every file has a set of ATTRIBUTES which defines the specification of the file.