Originally Posted by
tabstop
Sorry I missed the vector thing at first, see the edit.
Anyway, the size (be it 32MB, 100MB, or whatever) is not relevant, because you're not going to process the whole file at a time; if you ever even try to put the whole bloody file in memory, you're just being silly. It looks like you have one (four-byte) hex number per line? Read in the number (you should be able to use the %x format specifier; make sure the target is a four-byte unsigned), process, write it out. Lather, rinse, repeat until you're out of hex. No reason to deal with more than one line at a time.