#!/usr/bin/perl -T --
use strict;
use warnings;
use CGI qw(:standard);

print header, start_html('Upload example');

print_form() unless param;
print_results() if param;
print end_html;

sub print_form {
  print
    h2('What file do you have for me?'),
    start_multipart_form(),
    filefield(-name => 'upload', -size=>60),
    submit(-label => 'Do it!'),
    end_form;
}

sub print_results {
  my $output_file = '../whatever';
  my $file = upload('upload');
  print h2('Bummer!...') and return
    unless $file and open my $out, ">$output_file";
  {
    my $data;
    print $out $data while read $file, $data, 1024;
  }
  close $out or
    print h2('Not all is well...') and return;
  print h1('Success!');
}