Update...
This works great in Linux but now I'm trying to get it working in Windows. The problem is that Windows doesn't seem to have the process print to the pipe that's attached to stdout. The only thing I can gather from testing variations is that STDOUT is the same for both "processes" in Windows. If I sleep and let the child run first or don't restore STDOUT, the pipe works as designed. As soon as I restore STDOUT, the pipe is broken even though they are separate processes.
Is there any way of doing this in Windows?
print "before the pipe\n";
open $old_stdout, ">&STDOUT" or die "open: $!";
local(*WH);
pipe $rh, WH;
open STDOUT, ">&WH" or die "open: $!";
STDOUT->blocking(0);
# write something to the pipe
# and have some fork/exec'ed process write to the pipe (via stdout)
if( fork() ) {
open( STDOUT, ">&", $old_stdout ) or die "open: $!";
print STDERR "I'm the parent\n";
sleep 3;
} else {
exec( 'echo fubar' );
exit( 0 );
}
close WH;
my $out = <$rh>;
print "got from pipe: $out"; # $out is empty since fubar printed to
+the screen
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