NetNews Usenet Archive 1992 #30/NN_1992_30.iso/spool/comp/unix/programm/5695

Text File | 1992-12-14 | 1.6 KB | 41 lines

Newsgroups: comp.unix.programmer
Path: sparky!uunet!arakis.fdn.org!gamb.fdn.org!fizz!ben
From: [e-mail] (Benoit Grange)
Subject: Re: Determining the state of a process on another host
Message-ID: <[e-mail]>
Sender: [e-mail] (Benoit Grange)
References: <[e-mail]>
Date: Mon, 14 Dec 1992 18:07:23 GMT
Lines: 30

In article <[e-mail]> [e-mail] (Barry
Margolin) writes:
> In article <[e-mail]> [e-mail] (Mads Westermann)
writes:
> >I'm currently writing a client-server application that uses BSD
> >sockets to communicate. At certain stages in the processing I
> >want to be able to determine whether the client process is
> >running/alive.
>
> If you're using a stream socket, you can try to write something to it.
> When the client process died, the remote system should have closed the
> connection.  If you try to write to a closed connection you should get
an
> error (EPIPE, I think).

If you are watching via a select() the status of your stream socket, the
select() call will report something to read or some exeptional event as
soon as the other side of the socket is closed.

The 'are you there ?' method suggsted by [e-mail] is also a
good method if the remote process is not busy in a long calculation.

Datagramm sockets should report 'port is unreachable' if no program is
listening on the remote port you requested, but I never seen it working.

--
----
Benoit Grange - PARIS - FRANCE

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