Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
Hi, Here is just some general advice. I would suggest you add some code which detects errors as they occur, and prints out some sort of message so you can locate where your script is actually failing. See Simple threaded chat server and if you want, see Gtk2 server and client GUI's with root messaging for an example of a Gtk2/Glib event-loop socket script which can detect different error conditions. You can check for different socket conditions, like 'in', 'nohup', 'error' and if there is any data. The key test is if there is an 'in' condition, but no data to be read, you have to assume the connection has failed somewhere, and this close the socket and remove it from your select array.

In your code, try sprinkling warnings after socket operations, or print a debug message at critical points to see where your code fails when it crashes. Just as a longshot, that sometimes works, try putting $SIG{CHLD} = 'IGNORE' in your script.

If you are going to stick with a select() while loop, it sometimes is useful to test for $socket->can_write at an appropriate place to give an indication that the socket is still alive.

#!/usr/bin/perl use warnings; use strict; use IO::Socket; use IO::Select; my @sockets; my $machine_addr = 'localhost'; my $main_sock = new IO::Socket::INET(LocalAddr=>$machine_addr, LocalPort=>1200, Proto=>'tcp', Listen=>3, Reuse=>1, ); die "Could not connect: $!" unless $main_sock; print "Starting Server\n"; my $readable_handles = new IO::Select(); $readable_handles->add($main_sock); while (1) { # my ($new_readable) = IO::Select->select($readable_handles, undef, u +ndef, 0 ); # causes 100% cpu usage my ($new_readable) = IO::Select->select($readable_handles, undef, un +def, undef ); foreach my $sock (@$new_readable) { if ($sock == $main_sock) { my $new_sock = $sock->accept(); $readable_handles->add($new_sock); } else { my $count = sysread $sock, my $buf, 1024; print "$count\n"; if ($buf) { print "$buf\n"; my @sockets = $readable_handles->can_write(1); print "@sockets\n"; #print $sock "You sent $buf\n"; foreach my $sck(@sockets){print $sck "$buf\n";} } else { $readable_handles->remove($sock); close($sock); } } } } print "Terminating Server\n"; close $main_sock; getc();
Here is a basic forking client that works really well for testing connections, the fork separates the send from the receive.
#!/usr/bin/perl -w use strict; use IO::Socket; my ( $host, $port, $kidpid, $handle, $line ); #unless ( @ARGV == 2 ) { die "usage: $0 host port" } ( $host, $port ) = @ARGV || ('localhost',8989); # 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 $line; } }
It can get confusing, I hope the above helps you out.

I'm not really a human, but I play one on earth. ..... an animated JAPH

In reply to Re: Client-Server app by zentara
in thread Client-Server app by radu

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others cooling their heels in the Monastery: (6)
    As of 2020-10-23 22:35 GMT
    Find Nodes?
      Voting Booth?
      My favourite web site is:

      Results (241 votes). Check out past polls.