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Right choice is (a) True

To elaborate: Using zip and unzip command we can compress, archive, uncompress FILES. So these two COMMANDS can PERFORM all the functions which are PERFORMED by gzip, gunzip and TAR.

The correct option is (a) -V

Explanation: We can view the COMPRESSED archive using the -v option. The OUTPUT list will show both compressed and uncompressed size of each file in the archive ALONG with the PERCENTAGE of compression achieved.

Correct CHOICE is (a) True

For EXPLANATION I WOULD SAY: If we invoke the following command,

Right option is (c) unzip

For explanation: unzip command is used for RESTORING FILES which are compressed USING zip command. To unzip a file, SIMPLY type the filename as an ARGUMENT with unzip command.

Correct answer is (a) True

For EXPLANATION I would SAY: Just like other UNIX commands, zip command can also perform recursive COMPRESSION. In recursive compression, it will compress all the subdirectories and files that will be ENCOUNTERED while tracing the tree STRUCTURE.

The correct option is (a) True

For explanation I would say: For using ZIP COMMAND, the FIRST argument should be a COMPRESSED filename, the REMAINING arguments are interpreted as files and directories to be compressed.

The correct OPTION is (d) zip

To elaborate: zip command combines the work of both GZIP and tar i.e. it can COMPRESS and archive files together. The compression ratio using zip is lower as COMPARED to bzip2 or gzip.

The correct OPTION is (d) -r

The EXPLANATION: We can append files to an archive which is CREATED already using -r option with TAR.

Correct choice is (b) TAR -cvffile01file02abc.tar

To EXPLAIN I WOULD say: To create an archive -c option is used, -v is used to display the progress while tar works while -f is used to specify the name of the archive. All these OPTIONS can be combined together as (-cvf).

Correct answer is (a) tar -tvfabc.tar

To explain I would say: -t OPTION is used with tar for viewing the contents of the ARCHIVE in a table manner. It does not extract files rather it simply shows their ATTRIBUTES in a suitable form CONTAINING file permissions, file size and file name.

Right option is (d) tar

The explanation is: For archiving files to the disk we use tar. It can be USED to archive a group of files or an entire DIRECTORY structure. tar program provides a handful of UTILITIES like creating, maintaining, modifying and extracting files that are in tar format. Tar STANDS for ‘tape ARCHIVAL’.

Correct option is (a) True

Best EXPLANATION: MULTIPLE files can be UNZIPPED using gunzip command by providing multiple FILENAMES as arguments to the command.

The correct option is (b) BZIP2 and bunzip2

Best EXPLANATION: For many years, gzip remained as the most favorite compression utility but now we have a better ONE CALLED bzip2 (bzip2 and bunzip2). bzip2 is slower than gzip and it creates files with .bz2 extension.

The CORRECT OPTION is (b) False

To ELABORATE: gzip can ALSO be used to uncompress files, all we have to do is to use -d option with gzip command.

Right answer is (d) -r

To explain: Like many other UNIX commands, we can PERFORM recursive compression. Through this process, we can compress all files in the DIRECTORY. To perform this operation, -r option is USED with gzip COMMAND.

Right option is (B) .gz

The explanation: gzip adds an extension to the filename after compressing it and REMOVES the original FILE. For example, if we COMPRESS a file named file01.txt using gzip then the new filename will be file01.txt.gz.

The correct answer is (b) GZIP

To explain I WOULD SAY: To conserve DISK space we need to compress a file. gzip is a very POPULAR program used with one or more filenames for compression.

The correct option is (d) z

To explain I would SAY: more pager offers a set of INTERNAL COMMANDS which are used for viewing PAGES differently. For scrolling one page at a time, use ‘F’ or the space bar. Similarly for scrolling backward press ‘b’ and for quitting the pager use ‘q’.

The correct choice is (C) more, pg

The explanation is: The man command displays its output one page at a time. This is possible because it sends its output to a pager PROGRAM. more pager is extensively used in UNIX system and it has replaced the ORIGINAL pager of UNIX i.e. pg. The task of a pager program is to simply display pages on the terminal. It can also be used to display the CONTENTS of a file.

Right option is (a) True

Best EXPLANATION: To print a specific title on the first page, we use the -t option FOLLOWED by the STRING which we WANT to print as a title. For EXAMPLE,

The correct option is (a) file

For explanation: UNIX provides the file command for determining the type of file i.e. WHETHER it is a text file, SCRIPT file, ARCHIVE file or any other type of file.

Right option is (d) -n

The explanation: If we want to PRINT multiple COPIES of a FILE, we can USE the -n option FOLLOWED by an integer i.e. the number of copies that we want to print. For example to print 5 copies of file abd.txt use the following command,

Right CHOICE is (B) -d

Explanation: lp command prints the file as a default printer has been already SPECIFIED by the system administrator. In case if there is more than one printer in the system we have to use the -d option with the printer name to print the file. For example, if there is another printer NAMED laser_001 then,

Correct OPTION is (c) -c

For explanation: -c option when used with WC COMMAND display only the number of characters in the specified file.

The correct OPTION is (d) -w

The explanation: -w option when USED with WC command display only the number of WORDS in the SPECIFIED file.

Correct OPTION is (d) wc

The explanation: UNIX PROVIDES a universal word counting program that ALLOWS us to count the NUMBER of words, lines and characters in a file. It takes a filename as an argument as produces a 4 column output.

The correct choice is (c) cmp

To elaborate: All the three commands comm, DIFF and cmp are used for comparing files but if we are interested in knowing WHETHER two files are identical or not we can USE comm command without any option. It will SIMPLY return the prompt without DISPLAYING any output if both the files are identical.

The correct answer is (b) False

Easy explanation: wc command can take MULTIPLE FILENAMES as arguments. If multiple filenames are specified with wc command then it will produce a separate line of OUTPUT for each file ALONG with an additional line as a TOTAL count for all files specified. For example,

The correct answer is (a) True

To explain: comm command only compares those FILES that are already sorted. If the files are not sorted it will THROW an ERROR MESSAGE displaying “file not in sorted ORDER”.

The correct choice is (b) Returns PROMPT

The best explanation: When two files are IDENTICAL, diff command does not produce any output. It simply returns the SHELL prompt $. However, we can USE the -s option to display an informative message on the terminal if the files are identical.

Correct option is (b) diff

Explanation: diff COMMAND is used for comparing FILES and DISPLAYING the DIFFERENCES between them.

diff command uses certain SYMBOLS and instructions to indicate the changes that are required to make two files identical. For example,

a– for appending

c– for changing

d– for deleting

Correct option is (a) -n

The explanation: We can limit the number of bytes to be compared by the cmp COMMAND by using -n option with it. For EXAMPLE, if we want to compare at most 50 bytes then the command will be written as:

Correct option is (c) comm

For explanation: comm COMMAND is used for comparing two sorted files line by line. When there is no option specified with comm command it PRODUCES three column output. For example, if we WANT to compare two files namely file01 and file02 then the first column will contain those entries which are unique to file01 whereas the SECOND column will contain those entries which are unique to file02. The third column will contain the ACTUAL information i.e. those entries which are common to both fil01 and file02.

Right CHOICE is (d) using -i option

To elaborate: We can skip the number of initial bytes to be compared from both the FILES such that the CMP command will not consider that number of bytes while comparing both files. For this FACILITY, we use -i option followed by the number of bytes to be skipped. For example, to skip the first 10 bytes use the FOLLOWING command,

The correct answer is (d) -l

To explain: cmp command by default only displays the first mismatch that OCCURS in both files. For a detailed LIST of all the mismatches, we use the -l option. It prints byte POSITION and the byte VALUE for all differing bytes.

The CORRECT answer is (a) 0

For explanation I WOULD SAY: The exit status of cmp COMMAND is 0 if both the files are identical and 1 if both the files are different. The exit status is 2 if the program encounters a problem.

The correct choice is (a) True

To explain: When -f OPTION is USED with mv command then, the system will not display any diagnostic messages on to the terminal. It will simply replace the EXISTING FILE without any warning.