How to calculate sha1sum of a file in c++?

Question

I tried system calls, but since it`s not the best solution I thought there should be some other way of calculating checksums.

Is there any library or function that enables calculating file's checksums in c++ with various algorithms?

Answer 1

Obviously, there will be lots of them. Crypto++ was the first one I found after a quick search, looks decent enough. Latest release dated mid-March 2009, so it seems "alive".