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.\" @(#)unix.4 6.3 (Berkeley) 3/28/91
.Fd #include <sys/types.h>
protocol family is a collection of protocols
that provides local (on-machine) interprocess
communication through the normal
filesystem pathnames for addressing.
addresses are variable-length filesystem pathnames of
.Bd -literal -offset indent
causes a socket file to be created in the filesystem.
removed when the socket is closed\(em\c
must be used to remove the file.
protocol family does not support broadcast addressing or any form
matching on incoming messages.
All addresses are absolute- or relative-pathnames
Normal filesystem access-control mechanisms are also
applied when referencing pathnames; e.g., the destination
protocol family is comprised of simple
transport protocols that support the
sockets also support the communication of
file descriptors through the use of the
Any valid descriptor may be sent in a message.
The file descriptor(s) to be passed are described using a
that is defined in the include file
The type of the message is
and the data portion of the messages is an array of integers
representing the file descriptors to be passed.
The number of descriptors being passed is defined
by the length field of the message;
the length field is the sum of the size of the header
plus the size of the array of file descriptors.
The received descriptor is a
of the sender's descriptor, as if it were created with a call to
Per-process descriptor flags, set with
Descriptors that are awaiting delivery, or that are
purposely not received, are automatically closed by the system
when the destination socket is closed.
.%T "An Introductory 4.3 BSD Interprocess Communication Tutorial"
.%T "An Advanced 4.3 BSD Interprocess Communication Tutorial"
is a registered trademark, so in the future this communications domain
will be known as the ``local'' domain,