[SOLVED] Perl

z99 · 05-03-2012, 02:51 AM

hi everyone,i write a simple script with chatbot::eliza module and it reads and write with socket,the problem is instead of delivering the chatbot to the client,it runs on the server side,it seems the object accept is not working as i get can't accept,it used to work with perl version 5.12,but not with 5.14.2 [after i update it]:
any help would be appreciated.

Quote:

[majid@localhost Perl]$ perl chatbot2.pl
Server Ready .........
Connection Accepted
Eliza: Hello, I am a computer program.
you: quit
Eliza: Goodbye. It was nice talking to you.
Cant Accept

Quote:

[majid@localhost Perl]$ telnet 127.0.0.1 2009
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Connection closed by foreign host.

and the code:

Quote:

use strict;
use IO::Socket;
use Chatbot::Eliza;
use POSIX 'WNOHANG';

$SIG{CHLD}=\&sig;
sub sig
{
while(waitpid(-1,WNOHANG)>0) {}
};

my $sver=IO::Socket::INET->new(LocalPort=>'2009',Listen=>20,Proto=>'tcp',Reuse=>1) or die 'Cant create Socket';
print "Server Ready .........\n";

my $clnt;
while(1)
{
$clnt=$sver->accept or die 'Cant Accept'."\n";
print 'Connection Accepetd'."\n";
defined (my $child=fork()) or die 'cant fork';
if ($child==0)
{
$sver->close;
interact($clnt);
exit 0; #when $child has done with sub simply exit
}
$clnt->close; #if its not child it is parent,we just close our copy of the connected socket and go back to the top of the loop to accept() another
#connection. While we are waiting for a new connection, the child is taking care of the old one.
}

sub interact #note:we read and write through the connected socket
{
my $s=shift;
my $bot=Chatbot::Eliza->new;
$bot->command_interface();
STDIN->fdopen($s,"<") or die 'stdin';
STDOUT->fdopen($s,">") or die 'stdout';
STDERR->fdopen($s,">") or die 'stderr';
$|=1; # $| the same is $s->autoflush(1);
}

pan64 · 05-03-2012, 03:14 AM

I'm a bit confused about it.
In your quote you wrote:
Connection accepted. It means it works. And also you can see the answer of Eliza.
The message Cant Accept means the socket has been closed and therefore $sver->accept fails.

You told it worked with perl 5.12, but did not work with 5.14.2. I assume it is somehow related to the Reuse=>1. Reuse is deprecated in 5.14.1 (use ReuseAddr instead is written), maybe this is the problem).

z99 · 05-03-2012, 03:26 AM

thanks for the answer,the right output is for the 2 quotes to be exchanged i mean,

when i run

Quote:

perl chatbot2.pl

.it should return

Quote:

Connection Accepted
Connection Accepted

for each Connection Accepted , there is a client

and when i run

Quote:

telnet 127.0.0.1 2009

, it should Deliver Eliza to the client,:

Quote:

[majid@localhost Perl]$ telnet 127.0.0.1 2009
Connection Accepted
Eliza: Hello, I am a computer program.
you: quit
Eliza: Goodbye. It was nice talking to you.

ReuseAddr=>1 doesn't work.
i don't know why but die 'cant accept', will show cant accept like its not working properly.
and also i try to install google-chrome and it tried to install and update some perl modules,can it be because of them?

pan64 · 05-03-2012, 03:31 AM

I cannot find 5.14.2 at http://perldoc.perl.org. Maybe you can use 5.14.1 just for testing. I see something changed in the socket implementation, but currently unsure if it is a bug or changed behavior or ???

z99 · 05-03-2012, 03:37 AM

download perl 5.14.2

Quote:

[majid@localhost Perl]$ perl -v

This is perl 5, version 14, subversion 2 (v5.14.2) built for i386-linux-thread-multi

Copyright 1987-2011, Larry Wall

Perl may be copied only under the terms of either the Artistic License or the
GNU General Public License, which may be found in the Perl 5 source kit.

Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl". If you have access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.

so if roll back to the old version,would it change the behavior of the updated modules too,i mean consider i switch to the old version but not the modules,what then! [if i'm not wrong]

z99 · 05-04-2012, 04:47 AM

Solved,it has nothing to do with the new version,this one works:

Quote:

use strict;
use IO::Socket;
use Chatbot::Eliza;
use POSIX 'WNOHANG';

$SIG{CHLD}=\&sig;
sub sig
{
while(waitpid(-1,WNOHANG)>0) {}
};

my $sver=IO::Socket::INET->new(LocalPort=>'12000',Listen=>20,Proto=>'tcp',Reuse=>1) or die 'Cant create Socket';
print "Server Ready .........\n";

my $clnt;
while(1)
{
next unless $clnt=$sver->accept;
print 'Connection Accepetd'."\n";
my $child=fork();
if ($child==0) # or if ($child),indicating,we are dealing with child
{
$sver->close;
interact($clnt);
exit 0; #when $child has done with sub simply exit
}
$clnt->close; #if its not child it is parent,we just close our copy of the connected socket and go back to the top of the loop to accept() another
#connection. While we are waiting for a new connection, the child is taking care of the old one.
}

sub interact #note:we read and write through the connected socket
{
my $s=shift;
STDIN->fdopen($s,"<") or die 'stdin';
STDOUT->fdopen($s,">") or die 'stdout';
STDERR->fdopen($s,">") or die 'stderr';
$|=1;
my $bot=Chatbot::Eliza->new;
$bot->command_interface();
}