#!/usr/bin/perl
use warnings;
use strict;
use Glib;

# Glib provides a few ready-made event  sources, 
#  Glib::Timeout, Glib::Idle, and Glib::IO->add_watch
#  read perldoc Glib::MainLoop

my $main_loop = Glib::MainLoop->new;

my $count = 1;
my $timer  = Glib::Timeout->add (1000, \&timer_callback, undef, 1 );

#my $timer  = Glib::Timeout->add ($interval, $callback, $data=undef, $pri-
#      ority=G_PRIORITY_DEFAULT)

#    * $interval (integer) number of milliseconds
#    * $callback (subroutine)
#    * $data (scalar)
#    * $priority (integer)

#    Run $callback every $interval milliseconds until $callback returns
#    false.  Returns a source id which may be used with
#   "Glib::Source->remove".  Note that a mainloop must be active for
#    the timeout to execute.

sub timer_callback{
     $count++;
     print "$count\n";
    return 1;
}

my $count1 = 1;
my $timer1  = Glib::Timeout->add (100, \&timer1_callback, undef, 1 );

sub timer1_callback{
     $count1++;
     print "\t$count1\n";
     return 1;
}


###  filehandle watch
open (FH, "+> test.log") or warn "$!\n";

Glib::IO->add_watch (fileno 'FH', ['in'], \&watch_callback, 'FH', 1 );

# integer = Glib::IO->add_watch ($fd, $condition, $callback, $data=undef, $priority=G_PRIORITY_DEFAULT)
#           * $fd (Glib::IO) file number, e.g. fileno($filehandle)
#           * $condition (Glib::IOCondition)
#           * $callback (subroutine)
#           * $data (scalar)
#           * $priority (integer)


$main_loop->run;
####################################################################
sub watch_callback {
    my ($fd, $condition, $fh) = @_;
    my @lines = <FH>;
    print @lines;
    #always return TRUE to continue the callback 
    return 1;
}