Slashdot Headline Grabber for *nix

[czyrda]

Category:

Web Stuff/GUI

Description:

Gets the Slashdot headlines every 30 minutes.

#!/usr/bin/perl -w
use strict;
use Tk;
use Socket;
use IO::Handle;
use HTML::Entities; 
my (%stories, @bs, @binds, $mw, $value, $scale, 
    $scaled, $frame, $timer, $pid, $prog);
$prog = q(use Socket;
      $inet = inet_aton "www.slashdot.org";
      $proto = getprotobyname "tcp";
      socket(S, PF_INET, SOCK_STREAM, $proto) || exit;
      if(connect(S, pack "SnA4x8", 2, 80, $inet)) {
          select S;
          $| = 1;
          print "GET /slashdot.rdf HTTP/1.0\n\n";
          select STDOUT;
          $| = 1;
          while (<S>) {
          $title = $1 if /\<title\>(.*)\<\/title\>/;
          $url = $1 if /\<link\>(.*)\<\/link\>/;
          if (/<\/item>/) {
              print length($title),":",$title,$url,"\n";
          }
          }
          close S;
          close STDOUT;
      });
@binds = ('<Enter>', '<Motion>', '<Leave>', '<1>', '<B1-Motion>', 
      '<B1-Leave>', '<B1-Enter>', '<ButtonRelease-1>', '<2>',
      '<B2-Motion>', '<B2-Leave>', '<B2-Enter>', '<ButtonRelease-2>');
$scaled = 1;
$mw = MainWindow->new;
$mw->resizable(0, 0);
$mw->configure(-title => 'Slashdot Headline Grabber');
$mw->repeat(1800000, \&Get);
$frame = $mw->Frame(-relief => 'ridge', -borderwidth => 2);
@bs = ($frame->Button(-text => 'Get',
              -activebackground => '#43ce80',
              -command => \&Get),
       $frame->Button(-text => 'Clear',
              -activebackground => '#43ce80',
              -command => \&Cancel), 
       $frame->Button(-text => 'Exit',
              -activebackground => '#43ce80',
              -command => \&Leave)
       );
$scale = $mw->
    Scale(-showvalue => 0,
      -relief => 'flat',
      -sliderrelief => 'flat',
      -background => '#43ce80',
      -borderwidth => 0,
      -troughcolor => 'white',
      -orient => 'horizontal',
      );
map($mw->bind("Tk::Scale", $_, ""), @binds);
$frame->pack(-anchor => 'n', -expand => 1, -fill => 'x'); 
map($_->pack(-side => 'left', -expand => 1, -fill => 'x'), @bs);
$scale->pack(-anchor => 'nw', -expand => 0);
MainLoop;
sub Scale () {
    $_ = $scale->get();
    if ($_ <= 0) {$scaled= 1}
    if ($_ >= 100) {$scaled = -1}
    $scale->set($_ + $scaled);
}
sub Get () {
    &Cancel;
    $timer = $mw->repeat(9, \&Scale); 
    $pid = open (A, "perl -e '$prog'|");
    $mw->fileevent(\*A, 'readable', [\&Insertt]);
}
sub Cancel () {
    &Abort;
    &Clear;
}
sub Abort () {
    if ($pid) {
    kill 9, $pid;
    close A;
    $mw->fileevent(\*A, 'readable', '');
    $pid = 0;
    $timer->cancel();
    $scale->set(0);
    $timer = 0;
    }
}
sub Browser ($) {
    if (-l "$ENV{'HOME'}/.netscape/lock") {
    system(qq/netscape -remote 'openURL($_[0], new-window)' &/);
    } else {
    system(qq/netscape $_[0] &/);
    }
}
sub Clear () {
    map($_->[1]->destroy, values %stories);
    %stories = ();
}
sub Leave () {
    &Abort;
    exit;
}
sub Insertt () {
    my ($button, $title, $url);
    $_ = A->getline;
    if (defined $_) {
    chop;
    if(!/^(\d+):/ || 
       !$1 ||
       !/$1:(.{$1})(.+)/
       ) {return}
    ($title, $url) = ($1, $2);
    decode_entities($title);
    $button = $mw->Radiobutton(-anchor => 'w',
                   -indicator => 0,
                   -relief => 'groove',
                   -activebackground => '#43ce80',
                   -text => $title, 
                   -value => $title,
                   -variable => \$value,
                   -command => sub {           
                       $stories{$value}[1] -> flash();
                       Browser($stories{$value}[0]);
                       $stories{$value}[1] -> deselect();
                   })
        ->pack(-fill => 'both', -expand => 1);
    $stories{$title} = [$url, $button];
    } else {&Abort}
}

[merlyn]

Much simpler to grab the RSS RDF file instead. And it can be parsed by XML::RSS rather directly. I have a WebTechniques column that fetches RSS files on a regular basis, sending you just the updated headlines.

-- Randal L. Schwartz, Perl hacker

[maksl]

indeed it's much simpler to grab the rss rdf file with LWP::Simple && parse with XML::RSS :)
code example:


#!/usr/bin/perl -w

use strict;
use XML::RSS;
use LWP::Simple;
my $news = ( 'slashdot' => ['Slashdot',
                          'http://slashdot.org/slashdot.rdf']
# add some more rss news sites ..
            );

foreach my $news ( keys %news) {
        $rsspage=get $news{$news}[1];
        print "$news{$news}[0]:\n";
        $rss = new XML::RSS;
        $rss->parse($rsspage);
        foreach my $item (@{$rss->{'items'}}) {
                print "\t$item->{'title'}\n";
                print "\t$item->{'link'}\n\n";
        }
}

just add the timer for your convinience :)

[httptech]

You have to realize that my original code was not written for simplicity by using modules; it was designed to make the smallest possible .exe file when compiled. So I did away with LWP::Simple and used Socket because it saved 200K. I don't know how many extra kilobytes would have been used by the XML:RSS module, but I'm betting it's a lot more than are used by 3 or 4 lines worth of regexs.

[httptech]

Who compiles to ".exe" files?

If you want to share your cool new GUI Perl app with other Windoze users it doesn't seem likely that they will want to install Perl on their system just to run your app.

[merlyn]

Who compiles to ".exe" files? All that does is slow them down.

-- Randal L. Schwartz, Perl hacker

[cleen]

Very cool, and with the use of Socket; too!