Using sed, how do I insert text above the first match found?

Question

I'm using sed to modify a codebase. I'm trying to add an [assembly: .. ] reference and for readability's sake I'd like it to appear as the first [assembly: ] reference.

How might I do this in sed?

Answer 1

Use the insert command of sed to insert something before a match.

% sed "/yourmatch/i'[assembly:..]'" <<< $'hello\nworld\nyourmatch\matches'
hello
world
'[assembly:..]'
yourmatchmatches

For further information, see man sed.