Things get complicated fast, if you want a bidirectional client that connects to multiple servers simultaneously. See Simple bi-directional forking commandline client for a single connect client. You could do probably it with select, but it will involve a complex while loop check like this:

# very crude pseudocode
my $select = IO::Select->new($server1);
$select->add($server2);
$select->add(/*STDIN);  #for sending
# etc etc

my @ready;

while(@ready = $select->can_read) {
   my $socket;
   for $socket (@ready) {
       # see if you can read a socket
        .....
        .....
    }

#see if $select handle is STDIN, if so, send it to all in @ready
}

# do socket close error checking here
[download]

First of all thanks for your reply. I will look through links your provided. POE is good idea but the modules is very huge enough to sit in memory constrains applications devices.So i planned to write of my own server and client that suits for my application. Pblm with select is that its behavior is different for platform like Windows and Linux. One example is, STDIN won't work in Windows with select. This has been explained in Network Programming with Perl by Lincoln D. Stein many years back. Over these years any solution has been found for that or i don't know(If there pls provide link for the same). I want to design a platform independent server and client. Provide me if any other way of multitasking.without forks or thread(both has drawback as memory usage. Any other go for memory constrain applications.(or only option is select??).

One example is, STDIN won't work in Windows with select

So don't insist that everything is selectable. Use select on the sockets which is portable, and use a thread for STDIN. There is only 1 STDIN, so the cost is minimal.

Your main dispatch loop then becomes something like:

my $Qstdin = new Thread::Queue;
async {
    $Qstdin->enqueue( $_ ) while defined( $_ = <STDIN> );
}->detach;

...

while( 1 ) {
    if( my @readers = $selector->can_read( 0.1 ) ) {
        ## See what they have to say
    }
    elsif( my @writers = $selector->can_write( 0.1 ) {
        ## Tell'em what they need to know
    }
    elsif( my @exceptors = $selector->has_exception( 0.1 ) {
        ## Deal with their tantrums
    }
    else {
        while( $Qstdin->pending ) {
            my $kbinput = $Qstdin->dequeue;
            ## do whatever
        } 
    }
}
[download]

That should be portable to any OS supporting threads:

• It uses one thread, so memory use is minimal.
• It requires no user locking or syncing. Simple code.
• Doesn't require you to do nasty things like using RAW mode.

  That means that all the facilties provided by the local shell, like:

  • Line buffering.
  • Line editing.
  • History.
  • Macro expansion.
  • Redirection.
  • etc.

  are available without any extra effort, code or complications on your behalf.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."