man2/getpeername.2

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  32 .\"     @(#)getpeername.2       6.5 (Berkeley) 3/10/91
  33 .\"
  34 .\" Modified Sat Jul 24 16:37:50 1993 by Rik Faith <faith@cs.unc.edu>
  35 .\" Modified Thu Jul 30 14:37:50 1993 by Martin Schulze <joey@debian.org>
  36 .\" Modified Sun Mar 28 21:26:46 1999 by Andries Brouwer <aeb@cwi.nl>
  37 .\" Modified 17 Jul 2002, Michael Kerrisk <mtk-manpages@gmx.net>
  38 .\"     Added 'socket' to NAME, so that "man -k socket" will show this page.
  39 .\"
  40 .TH GETPEERNAME 2 1993-07-30 "BSD Man Page" "Linux Programmer's Manual"
  41 .SH NAME
  42 getpeername \- get name of connected peer socket
  43 .SH SYNOPSIS
  44 .B #include <sys/socket.h>
  45 .sp
  46 .BI "int getpeername(int " s ", struct sockaddr *" name ", socklen_t *" namelen );
  47 .SH DESCRIPTION
  48 .BR getpeername ()
  49 returns the name of the peer connected to socket
  50 .IR s .
  51 The
  52 .I namelen
  53 parameter should be initialized to indicate the amount of space pointed to
  54 by
  55 .IR name .
  56 On return it contains the actual size of the name returned (in bytes).  The
  57 name is truncated if the buffer provided is too small.
  58 .SH "RETURN VALUE"
  59 On success, zero is returned.  On error, \-1 is returned, and
  60 .I errno
  61 is set appropriately.
  62 .SH ERRORS
  63 .TP
  64 .B EBADF
  65 The argument
  66 .I s
  67 is not a valid descriptor.
  68 .TP
  69 .B EFAULT
  70 The
  71 .I name
  72 parameter points to memory not in a valid part of the
  73 process address space.
  74 .TP
  75 .B EINVAL
  76 .I namelen
  77 is invalid (e.g., is negative).
  78 .TP
  79 .B ENOBUFS
  80 Insufficient resources were available in the system
  81 to perform the operation.
  82 .TP
  83 .B ENOTCONN
  84 The socket is not connected.
  85 .TP
  86 .B ENOTSOCK
  87 The argument
  88 .I s
  89 is a file, not a socket.
  90 .SH "CONFORMING TO"
  91 SVr4, 4.4BSD (the
  92 .BR getpeername ()
  93 function call first appeared in 4.2BSD), POSIX.1-2001.
  94 .SH NOTE
  95 The third argument of
  96 .BR getpeername ()
  97 is in reality an
  98 .I int *
  99 (and this is what 4.x BSD and libc4 and libc5 have).
 100 Some POSIX confusion resulted in the present
 101 .IR socklen_t ,
 102 also used by glibc.
 103 See also
 104 .BR accept (2).
 105 .SH "SEE ALSO"
 106 .BR accept (2),
 107 .BR bind (2),
 108 .BR getsockname (2)