Question

How many files are used for representing different standard streams?

(a) 1

(b) 2

(c) 4

(d) 3

This question was addressed to me in an internship interview.

I would like to ask this question from Redirection and Pipes in division The Shell of Unix

Answer 1

Correct answer is (d) 3

To explain I would say: The shell associates three files with the terminal –two for display and one for the keyboard. These special files are actually streams of characters which many commands see as input and output. Each stream is associated with a default device –which is terminal. These three files are:

•    Standard Input

•    Standard output

•    Standard error