Question

To replace the string ‘director’ in the first five lines of file emp.lst with ‘manager’ we can use _____

(a) sed  ‘s/director/manager/’ emp.lst

(b) sed ‘1-5s/director/manager/’ emp.lst

(c) sed ‘1,5s/director/manager/’ emp.lst

(d) sed ‘15s

This question was addressed to me in an internship interview.

I need to ask this question from sed command in portion Filters using Regular Expressions of Unix

Answer 1

Right answer is (c) sed ‘1,5s/director/manager/’ emp.lst

For explanation I would say: Performing substitution using sed is not only limited to a single character; it can be any string. Above command will replace the string ‘director’ with ‘manager’ in the first five lines of file emp.lst.