Programming Forums > Script Programming > Perl

nick · Aug 20th, 2005, 3:45 PM

Hi, I'm new to perl (allthough Im pretty good with php and delphi) and have been making some small programs. I just started a program and allready am stuck. I am trying to make a server/client app. All that th server does is accept connections, and on reading data from a client, sends it to every other one. The client should connect to the server, receive data from it, and send data to it, a very very simple chat application in short. I am having problems with the server, to manage the different connections, I am using the select() function, as described here:
http://www.perlfect.com/articles/select.shtml
My code allmost exactly the same as that, and it still deosnt work, for a start I would like it to print the data received from the clien on the screen, what is wrong here (it never prints the data to the screen)?:

(Toggle Plain Text)

#!/usr/bin/perl
#test script

use IO::Socket;
use IO::Select;

if(@ARGV < 1)
{
        printf("Usage:\ntest.pl <port to run on>\n");
        exit();
}

my $sock = IO::Socket::INET->new(
                                Proto=>"tcp",
                                LocalHost=>"Localhost",
                                Listen=>16,
                                Reuse=>1,
                                LocalPort=>$ARGV[0]
                                ) or die("Could not create socket!\n");


my $readSet = new IO::Select();
$readSet->add($sock);

while(1)
{
        my $rhSet = IO::Select->select($readSet, undef, undef, 0);
        foreach $rh(@rhSet)
        {
                if($rh == $sock)
                {
                        $newSocket=$rh->accept();
                        $readSet->add($newSocket);
                } else
                {
                        $buf=<$rh>;
                        if($buf)
                        {
                                printf "$buf";
                        } else
                        {
                                $readSet->remove($rh);
                                close($rh);
                        }
                }
        }
}

I have allready anticipated another problem I will have. As you see, it accepts any new sockets, but what if, I want to send data to all open sockets the server has received? I see no where (array, etc) where the sockets are saved. Any help?

prolog · Aug 22nd, 2005, 4:44 AM

Hi,

you'll have to use the operations IO:

ocket provides for reading and writing. Check the man-page for that. Secondly to get an array of all sockets that are ready to write to call IO:

ocket::can_write. This will return an array of all handles that are writable.

(Toggle Plain Text)

my @writers=$sel->can_write;
foreach my $cur (@writers){
# .....do sth
}

If it's just for learning do it that way. If not consider using POE.

So far ...

Aug 20th, 2005, 3:45 PM	#1
nick Newbie Join Date: Aug 2005 Posts: 1 Rep Power: 0	New to perl: Network programming question Hi, I'm new to perl (allthough Im pretty good with php and delphi) and have been making some small programs. I just started a program and allready am stuck. I am trying to make a server/client app. All that th server does is accept connections, and on reading data from a client, sends it to every other one. The client should connect to the server, receive data from it, and send data to it, a very very simple chat application in short. I am having problems with the server, to manage the different connections, I am using the select() function, as described here: http://www.perlfect.com/articles/select.shtml My code allmost exactly the same as that, and it still deosnt work, for a start I would like it to print the data received from the clien on the screen, what is wrong here (it never prints the data to the screen)?: (Toggle Plain Text) #!/usr/bin/perl #test script use IO::Socket; use IO::Select; if(@ARGV < 1) { printf("Usage:\ntest.pl <port to run on>\n"); exit(); } my $sock = IO::Socket::INET->new( Proto=>"tcp", LocalHost=>"Localhost", Listen=>16, Reuse=>1, LocalPort=>$ARGV[0] ) or die("Could not create socket!\n"); my $readSet = new IO::Select(); $readSet->add($sock); while(1) { my $rhSet = IO::Select->select($readSet, undef, undef, 0); foreach $rh(@rhSet) { if($rh == $sock) { $newSocket=$rh->accept(); $readSet->add($newSocket); } else { $buf=<$rh>; if($buf) { printf "$buf"; } else { $readSet->remove($rh); close($rh); } } } } #!/usr/bin/perl #test script use IO::Socket; use IO::Select; if(@ARGV < 1) { printf("Usage:\ntest.pl <port to run on>\n"); exit(); } my $sock = IO::Socket::INET->new( Proto=>"tcp", LocalHost=>"Localhost", Listen=>16, Reuse=>1, LocalPort=>$ARGV[0] ) or die("Could not create socket!\n"); my $readSet = new IO::Select(); $readSet->add($sock); while(1) { my $rhSet = IO::Select->select($readSet, undef, undef, 0); foreach $rh(@rhSet) { if($rh == $sock) { $newSocket=$rh->accept(); $readSet->add($newSocket); } else { $buf=<$rh>; if($buf) { printf "$buf"; } else { $readSet->remove($rh); close($rh); } } } } I have allready anticipated another problem I will have. As you see, it accepts any new sockets, but what if, I want to send data to all open sockets the server has received? I see no where (array, etc) where the sockets are saved. Any help?

Aug 22nd, 2005, 4:44 AM	#2
prolog Programmer Join Date: Jul 2005 Location: Germany Posts: 69 Rep Power: 4	Hi, you'll have to use the operations IO:ocket provides for reading and writing. Check the man-page for that. Secondly to get an array of all sockets that are ready to write to call IO:ocket::can_write. This will return an array of all handles that are writable. (Toggle Plain Text) my @writers=$sel->can_write; foreach my $cur (@writers){ # .....do sth } my @writers=$sel->can_write; foreach my $cur (@writers){ # .....do sth } If it's just for learning do it that way. If not consider using POE. So far ... __________________ -= C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do succeed, you will blow away your whole leg. =- Bjarne Stroustrup

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Programming Forums > Script Programming > Perl

New to perl: Network programming question