#!/usr/bin/perl
use CGI;
use JSON; 
use strict;

my $logtext;
my $logfile = 'c:/temp/web/update.log'; # somewhere writeable
my $q = new CGI;
my $action = $q->param('action');

if ($action =~ /update/){
  # do stuff to update database
  sleep 1;
  open OUT,'>', $logfile or die "$!";
  print OUT "Result of $action on\n".scalar(localtime)."\n";
  print OUT "Line $_ message\n" for (1..rand(10));
  close OUT;
  
  my $json = encode_json( { msg => "$action done" } );
  
  # response
  print $q->header( -type => 'application/json' ),$json;
  exit;
} 

if ($action eq "result"){
  # get results of last update
  if (-e $logfile){
    open IN,'<', $logfile or die "$!";
    $logtext = do {local $/;<IN>};
    close IN;
  }

  print $q->header( {-pragma =>'no-cache',
           -cache_control => "no-store,no-cache,must-revalidate"} ),
  $q->start_html,
  $q->pre($logtext),$q->end_html;
  exit;
}