Unix Questions and Answers – perl – A General Purpose Tool – 1

This set of Unix Multiple Choice Questions & Answers (MCQs) focuses on “perl – A General Purpose Tool – 1”.

1. Which one of the following is the most powerful filter?
a) awk
b) grep
c) sed
d) perl
View Answer

2. A perl program runs in a special interpretive mode.
a) True
b) False
View Answer

3. To test whether perl is in your PATH, use ____
a) perl -e
b) perl -i
c) perl -el
d) perl -ed
View Answer

$ perl -e ‘print(“perl is present”) ;’

4. It is often more convenient to save perl program files with ____ extension.
a) .gp
b) .sh
c) .awk
d) .pl
View Answer

5. ___ function is used for removing the last character from the line.
a) cut
b) chop
c) erase
d) split
View Answer

6. perl variables have no type and no initialization.
a) True
b) False
View Answer

7. When a string is used for numeral computations, perl converts it into ___
a) character
b) floating point number
c) number
d) boolean value
View Answer

8. If a variable is undefined, its value is ____
a) 0
b) 1
c) NULL
d) garbage
View Answer

9. Which of the following are concatenation operators?
a) /
b) .
c) _
d) \\
View Answer

$ perl  -e  '$x="san" ; $y="foundry" ; print($x . $y);'
sanfoundry

10. To repeat a string, perl uses ___ operator.
a) /
b) .
c) x
d) \\
View Answer

$ perl  -e  ‘print “*” x 10 ;’
**********

11. Which function is used by perl for displaying the length of a string?
a) string
b) len
c) split
d) length
View Answer

$x= “Abdullah”;
print length($x);       // prints 8

12. ___ function returns the first occurrence of a character in a string.
a) string
b) index
c) split
d) length
View Answer

$x= “Abdullah”;
print index($x,u);     // prints 3

13. For extracting a substring, ____ function is used.
a) string
b) index
c) substr
d) length
View Answer

$x= “abcdefghijklm”
$y= substr( $x, -3,2);   // extracts two characters from the third position on the right side
print “$y”;             // prints kl

14. substr function is also used to alter an existing string.
a) True
b) False
View Answer

$x= “abcdijklm”
substr($x,4,0)= “efgh” ;    // stuff $x with efgh without replacing any charcaters
print “$x” ;               //$x is now abcdefghijklm

15. Which function is used by perl for reversing a string?
a) rev
b) reverse
c) split
d) substr
View Answer

$x= “abcd” ;
print reverse($x) ;       / prints dcba

16. Which function is used for handling substitutions in perl?
a) tr
b) s
c) str
d) tr and s
View Answer

17. Which escape character is used for identifying a word character?
a) \s
b) \d
c) \w
d) \n
View Answer

\s - a whitespace character
\d - a digit
\w - a word character

18. We can use find command for testing files with perl.
a) True
b) False
View Answer

$x = “abc.txt” ;
print “File $x is readable\n” if -r $x ;

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