This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
The getpeername() function shall retrieve the peer address 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.
The address_len argument points to a socklen_t object which on input
specifies the length of the supplied sockaddr structure, and on
output specifies the length of the stored address. 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 protocol permits connections by unbound clients, and the peer
is not bound, then the value stored in the object pointed to by
address is unspecified.
The getpeername() function shall fail if:
EBADF The socket argument is not a valid file descriptor.
EINVAL The socket has been shut down.
The socket is not connected or otherwise has not had the peer
The socket argument does not refer to a socket.
The operation is not supported for the socket protocol.
The getpeername() function may fail if:
Insufficient resources were available in the system to
complete the call.
The following sections are informative.
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
IEEE/The Open Group 2013 GETPEERNAME(3P)