Originální popis anglicky: 
getsockname - get socket name
Návod, kniha: Linux Programmer's Manual
#include <sys/socket.h>
 
int getsockname(int s, struct sockaddr *name, socklen_t *namelen);
Getsockname 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.
  - EBADF
 
  - The argument s is not a valid descriptor.
 
  - EFAULT
 
  - The name parameter points to memory not in a valid
      part of the process address space.
 
  - ENOBUFS
 
  - Insufficient resources were available in the system to
      perform the operation.
 
  - ENOTSOCK
 
  - The argument s is a file, not a socket.
 
SVr4, 4.4BSD (the 
getsockname function call appeared in 4.2BSD). SVr4
  documents additional ENOMEM and ENOSR error codes.
The third argument of 
getsockname 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, also used by glibc. See also 
accept(2).
bind(2), 
socket(2)