negative numbers in case of different errors--and 0 on success.
- the variable `sha1` in the function signature of `get_sha1()` is `unsigned
negative numbers in case of different errors--and 0 on success.
- the variable `sha1` in the function signature of `get_sha1()` is `unsigned
is the binary representation, as opposed to the ASCII representation in
hex characters, which is passed as `char *`.
is the binary representation, as opposed to the ASCII representation in
hex characters, which is passed as `char *`.