#!/usr/bin/perl -w
#
# fetch a metar, taf or short taf from http://weather.noaa.gov
#
# This is designed to be used in a IFRAME and returns HTML.
# It will only query the website once every 30 minutes, the rest
# of the time it will cache the result in an 'easily guessable'
# place in /tmp (consider that as a warning).
#
# Call it from a web page like this:-
#
# <iframe src="cgi-bin/fetch_weather.pl?icao=EGSH&metar=1"
# name="METAR for EGSH" frameborder="1" width="90%" height="50">
# [Your user agent does not support frames or is currently configured
# not to display frames. However, you may visit
# <A href="cgi-bin/fetch_weather.pl?icao=EGSH&metar=1">METAR for EGSH</A>]
# </iframe>
#
# You can set as many of these as you like:-
# metar=1 for a metar (default, if no options)
# staf=1 for a short form (usually more uptodate) TAF
# taf=1 for a full 18 hour TAF
# break=1 insert a "<br /><br />" between each result
#
# $Id: cgi_weather.pl,v 1.1.2.1 2003/02/02 00:39:52 minima Exp $
#
# Copyright (c) 2003 Dirk Koopman G1TLH
#
use strict;
use CGI;
use Geo::TAF;
use LWP::UserAgent;
my $q = new CGI;
my $site_code = uc $q->param('icao');
my @sort;
push @sort, 'taf' if $q->param('taf');
push @sort, 'staf' if $q->param('staf');
push @sort, 'metar' if $q->param('metar') || @sort == 0;
my $dobrk = $q->param('break');
error("No ICAO (valid) site code ($site_code) specified") unless $site_code && $site_code =~ /^[A-Z]{4}$/;
my $base = "/tmp";
my ($sort, $fn, $started);
while ($sort = shift @sort) {
$fn = "$base/${sort}_$site_code";
my ($mt, $size) = (stat $fn)[9,7];
$mt ||= 0;
$size ||= 0;
my $brk = "<br /></br />" unless @sort;
if ($mt + 30*60 < time || $size == 0) {
fetch_icao($brk);
} else {
my $s = retrieve();
send_metar($s, $brk);
}
}
sub retrieve
{
open IN, "$fn" or die "cannot open $fn $!\n";
my $s = <IN>;
close IN;
return $s;
}
sub fetch_icao
{
my $brk = shift || "";
my $ua = new LWP::UserAgent;
my $req = new HTTP::Request GET =>
"http://weather.noaa.gov/cgi-bin/mget$sort.pl?cccc=$site_code";
my $response = $ua->request($req);
if (!$response->is_success) {
error("METAR Fetch $site_code Error", $response->error_as_HTML);
} else {
# Yep, get the data and find the METAR.
my $m = new Geo::TAF;
my $data;
$data = $response->as_string; # grap response
$data =~ s/\n//go; # remove newlines
$data =~ m/($site_code\s\d+Z.*?)</go; # find the METAR string
my $metar = $1; # keep it
# Sanity check
if (length($metar)<10) {
error("METAR ($metar) is too short");
}
# pass the data to the METAR module.
if ($sort =~ /taf/) {
$m->taf($metar);
} else {
$m->metar($metar);
}
my $s = $m->as_string;
send_metar($s, $brk);
store($s);
}
}
finish();
sub start
{
return if $started;
print $q->header(-type=>'text/html', -expires=>'+60m');
print $q->start_html(-title=>"Weather for $site_code", -style=>{'src'=>'/style.css'},);
$started = 1;
}
sub finish
{
print $q->end_html;
}
sub store
{
my $s = shift;
open OUT, ">$fn" or die "cannot open $fn $!\n";
print OUT $s;
close OUT;
}
sub send_metar
{
my $s = shift;
my $brk = shift || "";
start();
print "<div class=frame>$s</div>$brk";
}
sub error
{
my $err = shift;
my $more = shift;
print $q->header(-type=>'text/html', -expires=>'+60m');
print $q->start_html($err);
print $q->h3($err);
print $more if $more;
print $q->end_html;
warn($err);
exit(0);
}