[LON-CAPA-cvs] cvs: modules /gerd/scantron scantronserver.pl

[www]

www		Sun May 23 20:11:48 2004 EDT

  Added files:                 
    /modules/gerd/scantron	scantronserver.pl 
  Log:
  Device server automatically connects to server.
  Server takes control of scanner, reads data.
  
  

Index: modules/gerd/scantron/scantronserver.pl
+++ modules/gerd/scantron/scantronserver.pl
use strict;
use POSIX qw(:sys_wait_h);
use IO::Socket;
my $server_port=5664;
my $server=IO::Socket::INET->new(LocalPort => $server_port,
                                 Type      => SOCK_STREAM,
                                 Proto     => 'tcp',
                                 Reuse     => 1,
                                 Listen    => 10);
sub REAPER {
    1 until (-1 == waitpid(-1, WNOHANG));
    $SIG{CHLD} = \&REAPER;                 # unless $] >= 5.002
}

$SIG{CHLD} = \&REAPER;
my $pid;

while (my $client = $server->accept()) {
    next if $pid = fork;                    # parent
    die "fork: $!" unless defined $pid;     # failure
    # otherwise child
    my $caller = getpeername($client);
    my ($port,$iaddr);
    if (defined($caller) && length($caller) > 0) {
	($port,$iaddr)=unpack_sockaddr_in($caller);
    } else {
	exit;
    }
    my $hostname;
    my $clientip;
    if (defined($iaddr)) {
	$clientip=inet_ntoa($iaddr);
	$hostname=gethostbyaddr($iaddr,AF_INET);
    }
    print "\n$$: Connected $hostname $clientip\n";
    print $client "0\n";
    while (my $garbage=<$client>) {
	if ($garbage=~/\w/) { last; }
    }
    print "Communicating\n";
# Put into escrow mode
    print $client "e\n";
    while (my $line=<$client>) {
	&analyse($client,$line);
    }
    print "\n$$: Disconnect $hostname $clientip\n";
    exit;                                   # child leaves
}

#
# Analyse any data that comes from the scanner
#
sub analyse {
    my ($client,$data)=@_;
    print "\nData: $data";
    print $client "3\n";
}