The getsockname() function shall retrieve the locally-bound name of the
specified socket, store this address in the sockaddr structure pointed
to by the address argument, and store the length of this address in the
object pointed to by the address_len argument.
If the actual length of the address is greater than the length of the supplied
sockaddr structure, the stored address shall be truncated.
If the socket has not been bound to a local name, the value stored in the object
pointed to by address is unspecified.
Upon successful completion, 0 shall be returned, the address argument
shall point to the address of the socket, and the address_len argument
shall point to the length of the address. Otherwise, -1 shall be returned and
errno set to indicate the error.
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html