getsockname - get socket name
getsockname(2) returns the current name for the specified socket. The namelen parameter should be initialized to indicate the amount of space pointed to by name. On return it contains the actual size of the name returned (in bytes).
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.
The third argument of getsockname(2) is in reality an `int ' (and this is what BSD 4. and libc4 and libc5 have). Some POSIX confusion resulted in the present socklen_t. The draft standard has not been adopted yet, but glibc2 already follows it and also has socklen_t. See also accept(2).
NickJohnson adds: If getsockname is called on an unbound inet socket, ((struct sockaddr_in *)name)->sin_family will be AF_INET, and ((struct sockaddr_in *)name)->sin_addr.s_addr will be INADDR_ANY.