msalerno has asked for the wisdom of the Perl Monks concerning the following question:

I have a service that listens for commands, when a command is received it echo's it back to the client and in a log. It works fine when I telnet from the terminal, but i'm having problems scripting it. It doesn't seem to write to the socket. I can read from the socket, but I can't write to it. Whatever I print to the socket from the script, it should be echoed back to me and logged on the server, but I don't see it in either place. Upon connecting to the server, I receive: 
Trying to aquire lock on log
Connection Established
Lock aquired

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Then I send a string ending in a ; FYI, in the server, $/ = ";"; I've tried just about everything I can think of... Can anyone out there spot the error? Thanks 
#!/usr/bin/perl -w
use strict;
use IO::Socket::INET;

my $text = 'Hello;';

my $host = "10.10.30.130";
my $port = "5678";

my $sock = IO::Socket::INET->new(
   PeerAddr   =>   $host,
   PeerPort   =>   $port,
   Proto      =>   'tcp'
   );

$sock or die "Can't connect to $host:$port\n";

#$sock->autoflush(1);

my $input = "";
my $char = "";
until ($input =~ /Lock aquired\s*$/){
   sysread($sock, $char, 1);
   $input .= $char;
}
print $input;

#$sock->send($text );
#syswrite $sock,$text ;
print $sock $text ;

$sock->shutdown(1);
close $sock;

exit;

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Replies are listed 'Best First'.
Re: Read and write to socket
by BrowserUk (Patriarch) on Oct 16, 2007 at 21:35 UTC
[reply]
      I didn't think it was necessary since the exchange works perfectly when I do it manually using telnet. The server code part is working as expected, it's printing to a socket with the above code that I am asking about.
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Re: Read and write to socket
by zentara (Cardinal) on Oct 17, 2007 at 11:52 UTC
    Try this bi-directional client, it acts like telnet. 
    #!/usr/bin/perl -w
use strict;
use IO::Socket;

my ( $host, $port, $kidpid, $handle, $line );

( $host, $port ) = ('192.168.0.1',1200);

my $name = shift || '';
if($name eq ''){print "What's your name?\n"}
chomp ($name = <>);


# create a tcp connection to the specified host and port
$handle = IO::Socket::INET->new(
    Proto    => "tcp",
    PeerAddr => $host,
    PeerPort => $port
  )
  or die "can't connect to port $port on $host: $!";
$handle->autoflush(1);    # so output gets there right away
print STDERR "[Connected to $host:$port]\n";

# split the program into two processes, identical twins
die "can't fork: $!" unless defined( $kidpid = fork() );

# the if{} block runs only in the parent process
if ($kidpid) {

    # copy the socket to standard output
    while ( defined( $line = <$handle> ) ) {
                      print STDOUT $line;
                      }
    kill( "TERM", $kidpid );    # send SIGTERM to child
}

# the else{} block runs only in the child process
else {

    # copy standard input to the socket
    while ( defined( $line = <STDIN> ) ) {
        print $handle "$name->$line";
    }
}

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    I'm not really a human, but I play one on earth. Cogito ergo sum a bum
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[d/l]
Re: Read and write to socket
by ulfwil (Initiate) on May 11, 2011 at 06:44 UTC
    Hello, Did you ever found the problem in your code regarding this problem?
[reply]

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