#!/usr/bin/env perl
# weather_watch.pl
use strict;
use Getopt::Long;
use JSON::XS;
use LWP::Simple;
use Sys::Syslog;

my $app = bless { 
    city => 'London,uk',
};

GetOptions(
    $app,
    'city=s',
);

$app->init;
$app->run;

sub init {
    my ($app) = @_;

    openlog($0, 'pid', 'user');
    syslog("info", "Starting up");
    $SIG{TERM} = sub {
        $app->{should_stop} = 1;
    };
}

sub run {
    my ($app) = @_;

    my $url = "http://api.openweathermap.org/data/2.5/weather?q=$app->{city}";
    until ( $app->{should_stop} ) {
        if ( my $json = get($url) ) {
            my $data = decode_json($json);
            syslog("info", "Temperature is $data->{main}{temp}");
            syslog("info", "Wind speed is $data->{wind}{speed}");
        }
        sleep 5;        
    }
    syslog("info", "Shutting down");
    closelog();
}

##</code><code>##

#!/usr/bin/perl
# weathermon
use warnings;
use strict;
use Daemon::Control;
use Getopt::Long;

GetOptions(
    \ my %OPT,
    'city=s',
);
 
exit Daemon::Control->new(
    name        => "Weather watch daemon",
    path        => '/home/arun/test/weathermon',
 
    program     => '/home/arun/test/weather_watch.pl',
    program_args => [ '--city', $OPT{city} ],
 
    pid_file    => '/tmp/weathermon.pid',
)->run;

##</code><code>##

% ./weathermon status                   
Weather watch daemon                                      [Not Running]
% ./weathermon start 
Weather watch daemon                                          [Started]
% ./weathermon status
Weather watch daemon                                          [Running]
% ./weathermon stop  
Weather watch daemon                                          [Stopped]
% ./weathermon start -c Miami,us        
Weather watch daemon                                          [Started]
% ./weathermon restart          
Weather watch daemon                                          [Stopped]
Weather watch daemon                                          [Started]
%