fseeko/ftello not available in MSVC (used by fuzzy.c)

[memcorrupt]

MSVC does not have fseeko/ftello, causing compilation of the unmodified fuzzy.c file to fail on VS2022 (17.9.34728.123).

Relevant log entries (irrelevant paths stripped):

.\ssdeep\fuzzy.c(572,10): warning C4013: 'ftello' undefined; assuming extern returning int
.\ssdeep\fuzzy.c(575,7): warning C4013: 'fseeko' undefined; assuming extern returning int
fuzzy.obj : error LNK2001: unresolved external symbol fseeko
fuzzy.obj : error LNK2001: unresolved external symbol ftello
fatal error LNK1120: 2 unresolved externals

[a4lg]

Sorry for kept you waiting. Working on it...

[a4lg]

Okay, you are directly compiling fuzzy.c from MSVC, right? Then it makes sense.

fuzzy.c depends on POSIX fseeko / ftello functions but they are not directly supported by MSVC / VC++ CRT / Windows CRT. The only reason why the Windows binary DLL version compiles is because it depends on the MinGW CRT (that implements fseeko and ftello using background Windows CRT functions).

Compiling fuzzy.c without GNU Autotools harness is not officially supported but we're going to partially support it (note: it only applies to fuzzy.c and not entire ssdeep). Your issue will be fixed in this process.