See the manpage here for C.
See here for Python.
The recv() call is (normally) only used on a connected socket.
C
From the manpage
#include <sys/socket.h>
ssize_t recv(int sockfd, void *buf, size_t len, int flags);
ssize_t recvfrom(int sockfd, void *restrict buf, size_t len, int flags,
struct sockaddr *restrict src_addr,
socklen_t *restrict addrlen);
ssize_t recvmsg(int sockfd, struct msghdr *msg, int flags);The return value is:
- the number of bytes received, if positive;
- zero for when a socket has performed an orderly shutdown
- -1 on error.
Python
Basically the same as C, except
import socket
s = socket.socket(...)
number_of_bytes = s.recv(size_of_buffer)