[Nottingham] Tweaking the orientation flag in a jpeg

Roger Light roger at atchoo.org
Fri Sep 3 08:31:16 UTC 2010

Hi Camilo,

> If you have to write a program to tweak one byte in a file it might be
> worth looking at mmap(), there are examples online and there are fewer
> things to go wrong than if you try to read the whole file into memory.
> So a well written program using  mmap() might be smaller than one that
> uses traditional file IO.

A good point. I've not needed to use mmap before so it didn't cross my
mind, but it'd certainly be easier and less prone to error than
reading the file in.



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