Often I want to do a ctrl+Search on a lot of big files, but am only interested in searching the top of the file. E.g:
- searching through some saved emails (*.eml) I only want to search the headers
- Searching for photos taken with a particular camera, I only want to search the EXIF information.

If I could specify how many bytes I want it to search, then it would all happen a lot quicker.

Possible interface: In ctrl+Search, press 0 to search whole of files (default), 1 to search only first 1KB, 2 to search first 2KB, etc.

Not sure if it would ever be useful to be able to search just the ends of files.