getpeername - get name of connected peer
int getpeername(int s, struct sockaddr *name, int *namelen
Getpeername returns the name of the peer connected to socket
s. The namelen parameter should be initialized to indicate
the amount of space pointed to by name. On return it con-
tains the actual size of the name returned (in bytes). The
name is truncated if the buffer provided is too small.
On success, zero is returned. On error, -1 is returned, and
errno is set appropriately.
EBADF The argument s is not a valid descriptor.
The argument s is a file, not a socket.
The socket is not connected.
ENOBUFS Insufficient resources were available in the system
to perform the operation.
EFAULT The name parameter points to memory not in a valid
part of the process address space.
SVr4, 4.4BSD (the getpeername function call first appeared
accept(2), bind(2), getsockname(2)