Comparing app binaries on iOS using bash or C

Question

My iPhone is jail broken with full terminal support. I need something (that isn't cmp or diff ) to compare app binaries. Both those commands give me weird results, they basically say that both binaries are completely different, when I can see and know that only one byte has been changed.

Answer 1

If it's possible to build it for the iPhone, you could try bsdiff , it's a diff-like utility that is specifically designed to handle binary data. The tools you mention are meant for textual input when it comes to finding differences.

Failing that, you could try generating a brutally bloated textual representation, with a single byte per line (and no line number or offset!), and then text- diff ing that. It should pick up the single changed byte, but depending on the sizes of the files it might be very slow and/or unwieldy.