inserting text into a specific line

Question

I\'ve got a text file, and using Bash I wish to insert text into into a specific line.

Text to be inserted for example is !comment: http://www.test.com into

Answer 1

you can use awk as well

$ awk 'NR==5{$0="!comment: http://www.test.com\n"$0}1' file
!aaaa
!bbbb
!cccc
!ffffdd
!comment: http://www.test.com
!eeee
!ffff