un.h

<sys/un.h>(P)							<sys/un.h>(P)



NAME
       sys/un.h - definitions for UNIX domain sockets

SYNOPSIS
       #include <sys/un.h>

DESCRIPTION
       The  <sys/un.h>	header	shall  define  the sockaddr_un structure that
       includes at least the following members:


	      sa_family_t  sun_family  Address family.
	      char	   sun_path[]  Socket pathname.

       The sockaddr_un structure is used to store addresses for	 UNIX  domain
       sockets.	 Values	 of this type shall be cast by applications to struct
       sockaddr for use with socket functions.

       The sa_family_t type shall be defined as described in <sys/socket.h> .

       The following sections are informative.

APPLICATION USAGE
       The  size  of sun_path has intentionally been left undefined.  This is
       because different implementations use different	sizes.	For  example,
       4.3 BSD uses a size of 108, and 4.4 BSD uses a size of 104. Since most
       implementations originate from BSD versions, the size is typically  in
       the range 92 to 108.

       Applications  should  not  assume  a particular length for sun_path or
       assume that it can hold {_POSIX_PATH_MAX} characters (255).

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       <sys/socket.h> , the System Interfaces volume of IEEE Std 1003.1-2001,
       bind(), socket(), socketpair()

COPYRIGHT
       Portions	 of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information  Technol-
       ogy  --	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 .



POSIX				     2003			<sys/un.h>(P)