#!/usr/bin/perl

# Simple client for testing 
# https://www.perlmonks.org/?node_id=11151665

use strict;
use warnings;
$!=1;
use IO::Socket;

my $socket = IO::Socket::INET -> new 
          (PeerAddr  => 'localhost',
           PeerPort  => 8081,
           Proto     => 'tcp',
           Type      => SOCK_STREAM)
      or
die "Cannot open socket!";  

print "$socket";

my $cmd = <<'END_MESSAGE';
GET /DATA_String/{300 continuous characters of sensor data}HTTP/1.1
Some host line
Some Connection line
Some user-agent line, next line is blank

END_MESSAGE

$SIG{PIPE} = 'handler';
$SIG{INT}  = 'handler';
$SIG{QUIT} = 'handler';
$SIG{ALRM} = 'handler';

server_request($cmd);  #single request

close $socket;     #hang up
exit();


sub server_request
{
    my $cmd = shift;
    print "sending CMD to server\n";
    alarm(2);
    print $socket "$cmd";
    $socket->flush();
    alarm(0);
    

    print "client debug: back from server: \n";
    while (alarm(2),my $sResponse = <$socket>)
    { 
       alarm(0);
       print "from Server: $sResponse";
    }
    alarm(0);
}

sub handler
{
   my ($signo) = shift;
   if ($signo eq "INT" or $signo eq "QUIT")
   {
       print $socket "QUIT\n";
       close ($socket);
       exit (1);
   }
   elsif ($signo eq "ALRM")
   {
       print "server too slow - request timed out!\n";
       exit (2);
   }
   else  #SIGPIPE (probably!)
   {
       print "Server died with signal $signo\n";
       exit (3);
   }
}