more forking troubles

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

Trying with my server/client stuff.

Problem:

If I have a connect from a client, a program needs to be executed. each time when there is a connect from a client. But if the program isn't finished executing it needs to wait until it's finished and then start it...

My solution:

SERVER: #!/usr/bin/perl -w

use IO::Socket;
use Net::hostent;

$PORT = 9000;

$server = IO::Socket::INET->new( Proto     => 'tcp',
                                 LocalPort => $PORT,
                                 Listen    => SOMAXCONN,
                                 Reuse     => 1);
die "can't setup server" unless $server;

print "[Server $0 accepting clients]\n";

while ($client = $server->accept()) {
  $client->autoflush(1);
  my $pid = fork();
  if ($pid) {
    #parent
    my $hostinfo = gethostbyaddr($client->peeraddr);
    printf "[Connect from %s]\n", $hostinfo->name || $client->peerhost
+;
    print "Being Handled by child with pid $pid]\n";
    wait();
  } else {
    #child
    print $client "Welcome to $0.\n";
    system('./sleep.pl');
  }
  close $client;
}
[download]

My executing program(just for testing):

#!/usr/bin/perl -w

my $num=1;

foreach(1..5) {
  print "PRINT: $num\n";
  $num++;
  sleep 5;
}
[download]

But there is still a problem here :( when I telnet to the server the telent session keeps hanging after being finished. Si I assume if I write a client it also keeps hanging...

--
My opinions may have changed, but not the fact that I am right

Comment on more forking troubles Select or Download Code

Replies are listed 'Best First'.
Re: more forking troubles by Zaxo (Archbishop) on Dec 12, 2001 at 15:29 UTC
I think you want to call `exit 0;` in the child block when the child has done it's work. Alternatively, this may be a case where `exec("sleep.pl");` is useful. As it is, I think the kids will keep piling up, each wanting to act as a new server on the same connection. After Compline, Zaxo	[reply] [d/l] [select]
Re: more forking troubles by toadi (Chaplain) on Dec 12, 2001 at 15:30 UTC
Think I solved it myself: In the childe part ik put exit(0) after the exec sleep. This seems to solve the problem... UPDATE: Zaxo and me seem to have found the same solution on the same moment :) -- My opinions may have changed, but not the fact that I am right	[reply]