Regular expression in sed to replace C++ includes

Question

I'm trying to play with sed, to change all;

#include "X"

to:

#include <X>

However I can't seem to find a way to do this! - This is what I've done so far:

sed -i 's/#include ".*"/#include <.*>/g' filename

I think I'm in need of a variable to save the contains of ".*", i'm just unaware of how!

Answer 1

Yes, you do. Regexps use () to save the contents of a match and a \1 to retrieve it. If you use more than one set of (), then the 2nd match is in \2 , and so on.

sed -e 's/#include "\(.*\)"/#include <\1>/g' < filename

will do what you need.