inline int ftruncate()

in src/mman.h [213:239]

• 26 lines of code
• 6 McCabe index (conditional complexity)

inline int ftruncate(const int fd, const int64_t size) {
    if (fd < 0) {
        errno = EBADF;
        return -1;
    }

    HANDLE h = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
    LARGE_INTEGER li_start, li_size;
    li_start.QuadPart = static_cast<int64_t>(0);
    li_size.QuadPart = size;
    if (SetFilePointerEx(h, li_start, NULL, FILE_CURRENT) == ~0 ||
        SetFilePointerEx(h, li_size, NULL, FILE_BEGIN) == ~0 ||
        !SetEndOfFile(h)) {
        unsigned long error = GetLastError();
        fprintf(stderr, "I/O error while truncating: %lu\n", error);
        switch (error) {
            case ERROR_INVALID_HANDLE:
                errno = EBADF;
                break;
            default:
                errno = EIO;
                break;
        }
        return -1;
    }        
    return 0;
}