I'm going over your code for clues that may help me. In the meantime, here is the code I am working on. Server.pl works fine as is, but if I try to put the code inside a while loop (I have tried both inside the socket open/close calls and outside) it quits working.

edit: I changed my server.pl a bit based on what I saw in your example. This does not work. The while loop goes through the first iteration fine, and hangs up the second time through with a (error|warning) message of "Use of uninitialized value in substitution (s///) at /clocal/mptsgrp/user/mptsuser/scripts/guipartner.pl line 24, <GEN1> line 2."
The print statements I included for debug show that $incoming matched /.+/ even after it was set to "" on the first iteration, but it did fail the $command[0] eq "check" test. The killer, though, is that the while loop stopped there. "Hi" was never printed a third time. :-( 
#!/usr/bin/perl
use strict;
use warnings;
use IO::Socket;
my $incoming;
my $check;
my @check;
my @command;
my $new_sock;

my $sock = new IO::Socket::INET (
                LocalPort => '8888',
                Proto => 'tcp',
                Listen => 1,
                Reuse => 1,
                );
die "Could not create socket: $!\n" unless $sock;
$new_sock = $sock->accept();
while ($incoming = <$new_sock>){
    print "hi";
        if ($incoming =~ m/.+/){
        print $incoming;
        @command = split / /,$incoming;
        $command[1] =~ s/\W+//g;
        $incoming = "";
        if ($command[0] eq "check"){
                $check = @check = `ps -ef |grep $command[1]`;
                print "$check\n@check\n";
                if ($check >= 12) {
                        print $new_sock "up";
                } else {
                        print $new_sock "down";
                }
        }else{
                print"did not work\n";
        }
    }
}
close $sock;

[download]


Likewise, the client works, so long as I don't duplicate the code to send a second request to the server.
#!/usr/bin/perl
use strict;
use warnings;
use IO::Socket;
use Fcntl;

my $input;
my $sock;
my $cs2;
my $mqpcx;
my $mpts;
my $EOL = "\015\012";
my $BLANK = $EOL x 2;
my $command;

open OUT, "> testpage.html" or die "unable to write testpage";
### OUT is temporary until I get cgi working.
open FILE1, "< 1.html" or die;
while (<FILE1>){print OUT}
close FILE1;
$sock = new IO::Socket::INET (
        PeerAddr => '53.230.116.97',
        PeerPort => '8888',
        Proto => 'tcp',
        );
if ($sock){
    print "Connection established\n";
    $command = "check cs2" . $BLANK;
    print $sock $command;
    while ($cs2 = <$sock>){
        last if ($cs2 =~ m/.+/);
    }
    if ($cs2 eq "up") {
        print OUT "<img src=\"./cs2up.gif\">\n";
        $mpts++;
        print"so far, so good\n";
    } elsif ($cs2 eq "down") {
        print OUT "<img src=\"./cs2down.gif\">\n";
    } else {
        print "error getting data from other box";
    }
}else{
    print OUT "<img src=\"./cs2down.gif\">\n";
    print "no connection to other box";
}

close($sock);
close OUT;
print "goodbye\n";

[download]

--
Believe nothing, no matter where you read it, or who said it - even if I have said it - unless it agrees with your own reason and your own common sense.
(Buddha)

In reply to Re^3: two-way socket works once only? by wolfger
in thread two-way socket works once only? by wolfger

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