sed: Replace part of a line

Question

How can one replace a part of a line with sed?

The line

DBSERVERNAME     xxx

should be replaced to:

DBSERVERNAME           


        

Answer 1

Others have already mentioned the escaping of parentheses, but why do you need a back reference at all, if the first part of the line is constant?

You could simply do

sed -e 's/dbservername.*$/dbservername yyy/g'