Kenichi Ishigaki


PAR::WebStart - Perl implementation of Java's WebStart


  my $file = 'hello.pnlp';
  my $ws = PAR::WebStart->new(file => $file);
  $ws->fetch_pars() or die $ws->{ERROR};

  my $tmpdir = $ws->{tmpdir};
  chdir($tmpdir) or die qq{Cannot chdir to "$tmpdir": $!});

  my @args = @{$ws->run_command()};
  die qq{Failed to get WebStart args: $ws->{ERROR}}) unless (@args);
  system(@args) == 0 or die qq{Execution of system(@args) failed: $?};


This a Perl version of Java's WebStart technology; see for details.

PAR-WebStart is a helper application associated with a browser. When a user clicks on a link that points to a PNLP [PAR Network Launch Protocol] launch file (a special XML file), it causes the browser to launch PAR-WebStart, which then automatically downloads, caches, and runs the specified PAR-based application.


PAR::WebStart::PNLP, for details of the PNLP file. Some utilities used here are described at PAR::WebStart::Util. Making a suitable par archive for use here is described in make_par. perlws describes how to associate PNLP files with the appropriate application to use.


Copyright, 2005, by Randy Kobes <>. This software is distributed under the same terms as Perl itself. See


Kenichi Ishigaki <>