ssize_t send (int, const void *, size_t, int);
ssize_t recv (int, void *, size_t, int);
ssize_t sendto (int, const void *, size_t, int, const struct sockaddr *, socklen_t);
ssize_t send (int, const void *, size_t, int);
ssize_t recv (int, void *, size_t, int);
ssize_t sendto (int, const void *, size_t, int, const struct sockaddr *, socklen_t);