Classical

Unix - Filters and Commands

66:  

 Which of the following programs are not interactive?

A.

passwd

B.

date

C.

grep

D.

Both (b) & (c)

 
 

Option: D

Explanation :


67:  

 lex can be used for

A.

Text processing

B.

Code enciphering

C.

Compiler construction

D.

All of these

 
 

Option: D

Explanation :


68:  

The number of errors in the following shell script
echo How are you?
read $answer
is

A.

0

B.

1

C.

2

D.

3

 
 

Option: C

Explanation :

Two mistakes. First is the ? . It is a meta character. So. when the shell encounters ? , it will try for a match, with the files in the current directory. made up of just one character. Use ? , to suppress the special meaning of ? . $answer means the value of the variable answer. Since you are reading the value of the variable answer, it should he read answer.


69:  

The read in the previous question is a

A.

Library function

B.

System call

C.

Shell command

D.

None of the above

 
 

Option: C

Explanation :


70:  

If lex .1 is a lex code then

A.

The command lex lex .1 invokes lex to act on lex .1

B.

The command lex lex.1 writes its output to the file lex.yy.c

C.

lex.yy.c has the definition of the function yylex

D.

All of these

 
 

Option: D

Explanation :




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