Domain Socket

[David S. Herron]

In article <1991Jan27.023818.4112 at cs.mcgill.ca> tinyguy at cs.mcgill.ca (Yeo-Hoon BAE) writes:
>This may not apply to the A3000UX, but what exactly is the
>'Domain socket'? I think it's only supported by Berkerley Unix.
>Thanks.

Sockets are "endpoints for communication" .. that is, they provide
a communications channel between two ports, the ports can be connected
to different processes, the same process, or to two processes on
two different systems.  The specifics depend on what kind of sockets
they are and the options you set on the socket when you open & connect it.

Unix Domain Sockets are the way BSD implemented pipes, but are more useful
than "just pipes".  There is also a "named" form of these, that is a
file system object which is one endpoint of a Unix Domain Socket, and
can be opened & read & written "just like a pipe".  It is somewhat
similar to USG's (System V) "named pipes".

Since I haven't (yet) bothered to look at any system Vr4 manuals I
can't say this for sure...

SysVr4 is supposed to have all the BSD features in there.  This should
include the Unix Domain Sockets, though they may be implemented as
a front end to named pipes.

Unix domain sockets, like pipes, only provide communication within a
single system.  If you want communication beyond a single system you
must use another addressing family.  (Unix domain sockets are just
one of the addressing families -- AF_UNIX).

In System V the preferred interface to this idea is "Transport Layer
Interface" (TLI).  It provides similar capabilities, with some interesting
differences and different terminology.


	David


-- 
<- David Herron, an MMDF & WIN/MHS guy, <david at twg.com>
<- Formerly: David Herron -- NonResident E-Mail Hack <david at ms.uky.edu>
<-
<-	MS-DOS ... The ultimate computer virus.