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 .