# RETURNS: ( $stdout, $stderr )  Both are refs to an array of lines.
sub OSexecute {
    my @execute = @_;

    local $, = ' ';  # for print "...@execute..."

    my $debug = 0;
    #$debug = 1;
    print("OSexecute(@execute)\n") if ($debug);

    # Here is the actual execution.
    my $pid = eval { open3($din, $dout, $derr, @execute) };
    die "OSexecute(@execute): $@" if ($@);

    # Wait for process to complete.
    waitpid($pid, 0);

    # Gather the results
    my @stdout = <$dout>;
    my @stderr = <$derr>;

    # We should check the return code of the child.
    # Gotta trap SIGPIPE for that.

    return ( \@stdout, \@stderr );
}

##</code><code>##

{
   my $file_name;

   foreach $file_name ('c:\\tinyfile.txt', 'c:\\biggfile.txt') {
      my ($stdout, $stderr);

      print("$file_name\n", ("=" x length($file_name))."\n", "\n");
      ($stdout, $stderr)
         = OSexecute('cmd.exe', '/c', 'type', "\"$file_name\"");
      print("stdout\n", "------\n", @$stdout);
      print("Nothing was sent to STDOUT.\n") unless (@$stdout);
      print("\n");
      print("stderr\n", "------\n", @$stderr);
      print("Nothing was sent to STDERR.\n") unless (@$stderr);
      print("\n", "\n");
   }
}

##</code><code>##

c:\tinyfile.txt
===============

stdout
------
foo
bar
bla

stderr
------
Nothing was sent to STDERR.


c:\biggfile.txt
===============
*** HANGS ***

##</code><code>##

# RETURNS: ( $stdout, $stderr )  Both are refs to an array of lines.
sub OSexecute {
    my @execute = @_;

    my @stdout;
    my @stderr;

    local $, = ' ';  # for print "...@execute..."

    my $debug = 0;
    #$debug = 1;
    print("OSexecute(@execute)\n") if ($debug);

    # Here is the actual execution.
    my $pid = eval { open3($din, $dout, $derr, @execute) };
    die "OSexecute(@execute): $@" if ($@);

    my $select = IO::Select->new();
    $select->add($dout);
    $select->add($derr);

    my @ready;
    my $fh;

    # Gather the results
    while (@ready = $select->can_read()) {
       foreach $fh (@ready) {
          push(@stdout, <$fh>) if ($fh == $dout);
          push(@stderr, <$fh>) if ($fh == $derr);
       }
    }

    # Wait for process to complete and reap it.
    waitpid($pid, 0);

    # We should check the return code of the child.
    # Gotta trap SIGPIPE for that.

    return ( \@stdout, \@stderr );
}