in reply to open3 buffering in linux vs. os x

You might want to try and set the output pipe filehandle to non-blocking on linux. 
 
use Fcntl;
# set non blocking and unbuffered  
my $flags = fcntl( OUTHANDLE, F_GETFL, 0 );  
cntl( OUTHANDLE, F_SETFL, $flags | O_NONBLOCK ); 

select((select(OUTHANDLE), $|=1)[0]);

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Re^2: open3 buffering in linux vs. os x
by Lexicon (Chaplain) on Jan 08, 2009 at 22:27 UTC
    Thanks! That was exactly what I was looking for. Alas, it didn't work. It blocks until QUIT like before. I suspect ProFit is just being clever, detected that it's not in a terminal, and is running in some kind of script mode.

[reply]
      You might try IO::Pty to fake it out. Here is a simple example, but you might want to google for better ones. 
      #!/usr/bin/perl
use IO::Handle;
use IO::Pty;

sub do_cmd() {
    my $pty = new IO::Pty;
    defined( my $child = fork ) or die "Can't fork: $!";
     if ($child){
          $pty->close_slave(); #needed to close
          return $pty;
    }
    

    POSIX::setsid();
    my $slave = $pty->slave;
    close($pty);
    STDOUT->fdopen( $slave, '>' ) || die $!;
    STDERR->fdopen( \*STDOUT, '>' ) || die $!;
    system("echo This is stdout output from an external program");
    exit 0;
}

my $fh = do_cmd();
while (<$fh>) { print; }

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