Of course it is possible with "editor" like tool. Imagine you have 400 000 file names and 5 000 strings you want to look for. Editor needs to make 400 000 x 5 000 string compares to show you result = 2 000 000 000 text compares! It isn't possible be done in one or two seconds.
-- <http://forum.pspad.com/read.php?2,63366,63425> PSPad freeware editor http://www.pspad.com
