#!/usr/bin/perl
#
# runs every hour. fetches website from env canada that has
# current winnipeg temperature.

use LWP::Simple;
use Time::Local;

#declare trim function
sub trim($);

$datestamp = time;

$url = sprintf "http://www.weatheroffice.gc.ca/city/pages/mb-38_metric_e.html";
$content = get($url);

$pattern = "\&deg;C</dd>";

$t_found= 0;
foreach $line (split /\n/ , $content) {

if ($t_found == 1 && $line =~ m/$pattern/) {
 $line = trim($line);
 $line = substr ($line, 4, index($line, "&")-4);
 $temp = $line;
 system("rrdtool update /home/alex/furnace/climate.rrd $datestamp:$temp:U");
}

if ($line =~ m/Temperature/) {
 $t_found = 1;
} else {
 $t_found = 0;
}

}


#trim subroutine
sub trim($) {
 my $str = shift;
 $str =~ s/^\s+//;
 $str =~ s/\s+$//;
 return $str
}