Re: Gtk2::Helper or Glib::IO event watcher problem

[muppet <scott asofyet org>]

On Mar 22, 2005, at 5:45 AM, Vyacheslav Dikonov wrote:

> I need to write a perl script that would act as a frontend to another 
> perl
> script and show its console output in a non-locking "realtime" manner. 
> The
> backend script does a lengthy job and outputs some messages via print
> "message\n"; . I want these messages to be received, parsed and 
> visualised
> by the frontend.
>
> It does sound like a FAQ, but unfortunately the FAQ did not help me.

hmmm.  there appears to be an html problem in the FAQ.

>         my $line = ;

the "<IN>" has been eaten by the browser.

i dropped that into the snippet you posted and it worked fine.  in 
fact, it wouldn't compile without it.


> Is there any other way to implement event based pipe reading with 
> Perl::Gtk2?

you could use Glib::IO->add_watch() directly; Gtk2::Helper is a wrapper 
that makes it behave more like the old Gtk-Perl.

This worked for me:


  #!/usr/bin/perl -w
  use strict;
  use Gtk2 -init;
  my $window = Gtk2::Window->new;
  my $scroll = Gtk2::ScrolledWindow->new;
  my $textview = Gtk2::TextView->new;
  my $buffer = $textview->get_buffer;
  $window->add ($scroll);
  $scroll->add ($textview);
  $window->show_all;
  $window->signal_connect (destroy => sub { Gtk2->main_quit });

  open(IN, q^perl -e '$|++; for($i=0;$i<10;$i++) { $sum+= $i; print 
"Line $i: sum = $sum\n"; sleep 1;}'|^)
       or die "Failed running perl subprocess\n";

  Glib::IO->add_watch ( fileno(IN), ['in', 'hup'], sub {
          my ($fileno, $condition) = @_;
          if ($condition eq 'hup') {
                  warn "done\n";
                  close IN;
                  return 0;  # uninstall
          }
          warn "reading...\n";
          my $line;
          sysread IN, $line, 1024;
          warn "read $line\n";
          $buffer->insert($buffer->get_end_iter, $line);
          return 1;
  });

  Gtk2->main;



--
I don't have a drinking problem,
'cept when i can't get drink.
  -- Tom Waits