GETPEERNAME(3P)            POSIX Programmer's Manual           GETPEERNAME(3P)

PROLOG
       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.

NAME
       getpeername -- get the name of the peer socket

SYNOPSIS
       #include <sys/socket.h>

       int getpeername(int socket, struct sockaddr *restrict address,
           socklen_t *restrict address_len);

DESCRIPTION
       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.

RETURN VALUE
       Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
       returned and errno set to indicate the error.

ERRORS
       The getpeername() function shall fail if:

       EBADF  The socket argument is not a valid file descriptor.

       EINVAL The socket has been shut down.

       ENOTCONN
              The socket is not connected or otherwise has not had the peer
              pre-specified.

       ENOTSOCK
              The socket argument does not refer to a socket.

       EOPNOTSUPP
              The operation is not supported for the socket protocol.

       The getpeername() function may fail if:

       ENOBUFS
              Insufficient resources were available in the system to complete
              the call.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       accept(), bind(), getsockname(), socket()

       The Base Definitions volume of POSIX.1-2017, <sys_socket.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       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
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                  2017                      GETPEERNAME(3P)