IO::Select will not work for non-socket filehandles under Win32; that includes STD(IN|OUT).

A relevant quote from "Network Programming with Perl", by Lincoln D. Stein:

Win32 Issues

Another problem arises when using multiplexed applications on Microsoft Windows platforms. When I originally developed the scripts in these chapters, I tested them on Windows98 using ActiveState Perl, and everything seemed to work fine. Later, however, I discovered that the gab5.pl script (Figure 12.1) was consuming a large amount of CPU time, even when it was apparently doing nothing but waiting for keyboard input.

When I tracked down this problem, I learned that the Win32 port of Perl does not support select() on non-socket filehandles, including STDIN and STDOUT. So client-side scripts that multiplex across STDIN do not wait for the filehandle to be ready, but just loop.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

use threads;
use threads::shared;

$| ++;

my $line = "";
share($line);

sub read_stdin {
    while (<STDIN>) {
        lock($line);
        $line = $_;
        print "child read in: $_\n";
    }
}

threads->create(\&read_stdin);
while (1) {
    if ($line ne "") {
        lock($line);
        print "parent process $line\n";
        $line = "";
    } else {
        print "do something else\n";
        sleep(1);#this nothing but to slow down the prints
    }
}
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Dis you test your code?! I made some tests for Thread too, but all the process stop when reading STDIN!!! :-/

Test Thread:

  use threads;
  use threads::shared;

  my ($BUFFER) : shared ;
  
  $thra = threads->new(\&read_stdin);
  $thrb = threads->new(\&send_sock);


  print "By!\n" ;
  
##############
# READ_STDIN #
##############

sub read_stdin {
  1 while( read( \*STDIN , $BUFFER, 1 , length($BUFFER) ) ) ;
}

#############
# SEND_SOCK #
#############

sub send_sock {

  my ($buf_lng) ;
  
  for(;;) {
    if ( length($BUFFER) > $buf_lng ) {
      my $buf = substr($BUFFER , $buf_lng-1 ) ;
      print "<$buf>\n" ;
    }
    $buf_lng = length($BUFFER) ;
  
    print ".\n" ;
    sleep(1) ;
  }
}
[download]

But thanks for the reply!

Graciliano M. P.
"The creativity is the expression of the liberty".

Of course, I tested my code before I post it. Before you question whether I tested my code, you better try my code out first. Everyone should only speak base on facts, not guesses.

Your threaded code does not work, does not imply all threaded code do not work.

But I will be happy to look into your code, and see why it is stuck. I will do this now.

Still looking at your code... First your code exited right after I started it. Reason? simple, because after it created two child threads, your main thread just print "bye" and exit. How did you test your code? I will add joins before bye.

...

Okay, tested your code. It died on you? Sorry it worked for me, after added:

threads::join($thra);
threads::join($thrb);
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Couple of things about your code:
1. You use $BUFFER without check whether it is undef, that causes lots of warning, when you do length($BUFFER) etc.
2. You better lock your shared variables before update them, although in your context, this not that serious a problem

Term::ReadKey allows a non-blocking read from the terminal, though not STDIN if it's re-directed.

$SIG{'CHLD'}='IGNORE';
$pid=fork;
if(!$pid´){
     (read stuff);
}
(stdin stuff);
[download]

sorry for that '´' in my reply