#! perl -slw
use strict;
use IPC::Open2;

$|++;

my $pid = open2 \*READ, \*WRITE, 'perl -wne "$|++; chomp; print"';

my $read = '';
for ( 1 .. 1e4 ) {
    Win32::Sleep( 10 );
    printf "\r$_\tGot'$read'\t";
    print WRITE 'some command';
}
__END__
c:\test>junk
Name "main::READ" used only once: possible typo at c:\test\junk.pl line 7.
83      Got''   Terminating on signal SIGINT(2)

##</code><code>##

#! perl -slw
use strict;
use IPC::Open2;

$|++;

my $pid = open2 \*READ, \*WRITE, 'perl -wne "$|++; chomp; print 1"';

my $read = '';
for ( 1 .. 1e4 ) {
    Win32::Sleep( 10 );
    printf "\r$_\tGot'$read'\t";
    print WRITE 'some command';
}
__END__
c:\test>junk
Name "main::READ" used only once: possible typo at c:\test\junk.pl line 7.
553     Got''   Terminating on signal SIGINT(2)

##</code><code>##

#! perl -slw
use strict;
use IPC::Open2;

$|++;

my $pid = open2 \*READ, \*WRITE, 'perl -wne "$|++; chomp; print 1"';

my $read = '';
for ( 1 .. 1e6 ) {
#    Win32::Sleep( 10 );
    printf "\r$_\tGot'$read'\t";
    print WRITE 'some command';
    sysread( READ, $read, 1024 );
}
__END__
c:\test>junk
1000000 Got'1'