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From: frechett@spot.Colorado.EDU (-=Runaway Daemon=-)
Subject: Re: What am I missing from chat2.pl?
Message-ID: <1991May27.215623.20884@colorado.edu>
Sender: news@colorado.edu (The Daily Planet)
Nntp-Posting-Host: spot.colorado.edu
Organization: University of Colorado, Boulder
References: <1991May27.120442.16645@colorado.edu> <1991May27.160539.8127@iWarp.intel.com>
Date: Mon, 27 May 1991 21:56:23 GMT
Lines: 69

In article <1991May27.160539.8127@iWarp.intel.com> merlyn@iWarp.intel.com (Randal L. Schwartz) writes:
>(I'm working on "select" right now, by the way.  Ugh. :-)
Uh oh.. this doesn't sound good.. as I picked up chat2 hoping to be able to 
do what I was trying to do with select.. 
Here's the situation.. I have a client (addapted from the in the man pages)
and I want to be able to poll stdin and the socket both.. Was hoping to 
find something in chat2.pl but if you haven't written a select then I 
suspect that I am am going to have a bit of aproblem..   

It is a simple matter to listen to the socket and parse what I see and 
such.. OR to listen to the users's input but as soon as I start to try to 
deal with both.. it stalls on something.. Here is a code fragment...

S is the socket.. 

sub fhbits {
	local(@fhlist) = split(' ',$_[0]);
	local($bits);
	for (@fhlist) {
		vec($bits,fileno($_),1)=1;
	}
	$bits;
    }
$rin = "";
$rin = &fhbits('stdin S');
# the problem here is that I don't see ANYTHING in $rin  Is it 
# unprintable.. and just what the hell is it anyway.. 
               if ($child = fork) {
                     for (;;) {
# it pauses here fine.. waiting for something to come through.. 
($nfound) = select($rout=$rin, undef,undef,undef);
# but I am totally stuck here... I couldn't see what $rin was and I can't 
# see what $rout is.. so I don't know what filedescriptors are ready.. 
# not only that but when I put in a line like... 
if ($nfound == 1) { read(S,$output,1024); print "$output"; } 
# and then sent it only stuff through the socket.. it still wasn't 
# trapping it.. It just froze stdin of course.. It just displays what is 
# coming throught the socket but the select didn't see it and read didn't see
# it..   What's wrong?
			if ($output =~ /^\/die|^\/quit/) { do dokill(); exit(0);}
[...]
                    }
                    sleep 3;
                    do dokill();
               }
# now on the other hand.. if I just poll the Socket and ignore stdin
# it reads the socket fine.. 
               else {
                    while (<S>) {
			if (/Temperature/ ) { print "Damn damn damn\n$_"; }
# we have a machine with a temperapture reading on some port.. 
                         print;
                    }
               }
exit(0);


I am confused.. and from what I can tell.. select(2) is not easy to 
deal with at all... Everyone I talk to either says.. 
"I don't know what to tell you"  or the classic
"Well it's been a long time and I did it in C but this should work.... "
And it never does.. 

Any help would be appreciated.. 

	ian

-=Runaway Daemon=-