#!/usr/bin/perl -w -t
#!/usr/local/bin/perl -w -t

#this is the script that is loaded first

#load support for strict variables
use strict;

#load support for printing to the screen - testing only
use CGI;
use CGI::Carp qw(fatalsToBrowser);
my $q = CGI->new;
print $q->header;
print "<p>start: $$<p>";


#load support for sockets
use IO::Socket;

#load posix support for named pipes
use POSIX qw(mkfifo);

#load support for finding the path to the process folder
use FindBin();
use File::Basename();
use File::Spec::Functions;

#load posix support for trapping signals
use POSIX();
#determine the current script path and name
my $script = File::Basename::basename($0);
my $SELF = catfile $FindBin::Bin, $script;
#create a new signal set
my $sigset = POSIX::SigSet->new();
#create the action you want performed on terminate signals
my $termAction = POSIX::SigAction->new('sigTERM_handler',
    $sigset,
&POSIX::SA_NODEFER);
#attach the signal to the action you want performed
POSIX::sigaction(&POSIX::SIGTERM, $termAction);

#start of the sub to run when the terminate signal arrives
sub sigTERM_handler {
    #store the signal sent by the system
    my $HTPad_signalCaught = shift;
    
    #run the handler for all exit signals
    &HTPad_exitSignalHandler("Terminate", $HTPad_signalCaught);
} #end of the sub to run when the terminate signal arrives

#start of the handler for all exit signals
sub HTPad_exitSignalHandler {
    #reinstate the passed variables
    my $HTPad_exitType = shift;
    my $HTPad_signalCaught = shift;
    
    unless (exec($SELF, @ARGV))
    { Die "Could not restart the script after a $HTPad_signalCaught si
+gnal was received: $!"; }
} #end of the handler for all exit signals

#turn on auto flush
$|=1;

#load required files
require './HTPadProcess_subs.pl';

#ignore child signals in order to do automatic child reaping
$SIG{CHLD} = 'IGNORE';

#enter the web server
&HTPad_webSserver();

#start of the web server
sub HTPad_webSserver {
    my %HTPad = ();
    my ($HTPad_server , $HTPad_client);
    
    #define the in out port
    $HTPad{port} = 5814;
    
    #define the server pipe names
    $HTPad{serverReadPipeName} = '.serverReadPipe.txt';
    $HTPad{serverWritePipeName} = '.serverWritePipe.txt';
    
    #open the TCP connection
    $HTPad_server = IO::Socket::INET->new(
        LocalPort => $HTPad{port},
        Type      => SOCK_STREAM,
        Reuse     => 1,
    Listen    => SOMAXCONN)
        or die "There is no tcp server on port $HTPad{port}: $!\n";
    
    #start of the parent server accepting clients
    while ($HTPad_client = $HTPad_server->accept()) {
        
        #auto flush the client
        $HTPad_client->autoflush(1);
        
        #start of forking a write child for the client
        unless ($HTPad{clientWritePID} = fork()) {
            #write child
            
            #turn off the posix sigterm handler
            $SIG{TERM} = 'DEFAULT';
            #turn off the posix sigint handler
            $SIG{INT} = 'DEFAULT';
            #turn off the posix sighup handler
            $SIG{HUP} = 'DEFAULT';
            #turn off the posix sigpipe handler
            $SIG{PIPE} = 'DEFAULT';
            
            #the read childcloses the unused server handle
            close ($HTPad_server);
            
            #get the pipe name from the parent server
            $HTPad{pipeName} = &HTPad_readFromPipe($HTPad{serverWriteP
+ipeName});
            
            #start of continuously wait for data from the read child
            while (1) {
                
                #get data from the read child
                $HTPad{ringData} = &HTPad_readFromPipe($HTPad{pipeName
+});
                
                #add test text
                #$HTPad{ringData} = $HTPad{ringData};
                
                #start of process test data
                if ($HTPad{ringData} =~ m/are you there/i) {
                    #send the data to the client
                    print $HTPad_client "The web server confirms your 
+write test:" . $HTPad{ringData} . "\015\12";
                    #end of process test data
                    
                    #start of process normal web server data
                    } else {
                    #send the data to the client
                    print $HTPad_client "This is the server and you wr
+ote: " . $HTPad{ringData} . "\015\12";
                } #end of process normal web server data
            } #end of continuously wait for data from the read child
            
            #close the write child connection
            close($HTPad_client);
            #exit the write child to keep it from accepting new client
+s
            exit(1);
        } #end of forking a write child for the client
        
        #start of checking the success of the forked write child
        if ($HTPad{clientWritePID} > 0) {
            #start of forking a read child for the client
            unless ($HTPad{clientReadPID} = fork()) {
                #read child
                
                #turn off the posix sigterm handler
                $SIG{TERM} = 'DEFAULT';
                #turn off the posix sigint handler
                $SIG{INT} = 'DEFAULT';
                #turn off the posix sighup handler
                $SIG{HUP} = 'DEFAULT';
                #turn off the posix sigpipe handler
                $SIG{PIPE} = 'DEFAULT';
                
                #the read childcloses the unused server handle
                close ($HTPad_server);
                
                #get the pipe name from the parent server
                $HTPad{pipeName} = &HTPad_readFromPipe($HTPad{serverRe
+adPipeName});
                
                #start of listen for data untill client connection clo
+ses
                while (defined ($HTPad{ringData} = <$HTPad_client>)) {
                    
                    #start of send the new data to the write child
                    if ($HTPad{ringData} ne '') {
                        
                        #add test data to the data
                        $HTPad{ringData} = $HTPad{pipeName} . " " . $H
+TPad{ringData};
                        
                        #send the data to the write child
                        &HTPad_writeToPipe($HTPad{pipeName}, $HTPad{ri
+ngData});
                    } #end of send the new data to the write child
                } #end of listen for data untill client connection clo
+ses
                
                #send sig term to write child when client closes conne
+ction
                kill ("TERM", $HTPad{clientWritePID});
                #close the read child connection
                close($HTPad_client);
                #exit the read child to keep it from accepting new cli
+ents
                exit(1);
            } #end of forking a read child for the client
        } #end of checking the success of the forked write child
        
        #start of checking the success of the forked write and read ch
+ild
        if ($HTPad{clientWritePID} > 0 and $HTPad{clientReadPID} > 0) 
+{
            #parent server
            
            #the server closes the unused read child handle
            close ($HTPad_client );
            
            #define the new clients pipe name
            $HTPad{pipeNameFromServer} = '.puppy_' . $HTPad{clientRead
+PID} . '.txt';
            #send the pipe name to the read child
            &HTPad_writeToPipe($HTPad{serverReadPipeName}, $HTPad{pipe
+NameFromServer});
            #send the pipe name to the write child
            &HTPad_writeToPipe($HTPad{serverWritePipeName}, $HTPad{pip
+eNameFromServer});
            
            #close the TCP connection after x connections - only when 
+not waiting for more clients.
            if (++$HTPad{clientCount} >= 2)
            { close($HTPad_server); }
        } #end of checking the success of the forked write and read ch
+ild
        
        #initialize the read and write pids
        $HTPad{clientWritePID} = 0;
        $HTPad{clientReadPID} = 0;
    } #end of the parent server accepting clients
    
    #close the parent server
    close($HTPad_server);
} #end of the web server

__END__
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