insert text in the middle of a file

Shell Programming and Scripting
1

I want to insert a text into the middle of a file

2

Assume the middle of the file is line 3, this adds a line just after line 2, that becomes the new line 3, old line 3 becomes 4, and so on:

sed '/2/a\
text to insert'  oldfile > newfile
3

Thanks, but i dont want to use sed or awk

4

Is this a homework question? If not, what is the real world problem?

Regards