On Jul 18, 6:49 pm, [EMAIL PROTECTED] (Monty) wrote:
> In studying network programming (and I'm just beginning at it), I see
> where listen() is called to set up a socket that waits for incoming
> connection requests. The next step appears to be a call to accept()
> where the request is granted and the connection made on a new socket,
> as in this code snippet:
>
> listen(SOCK,SOMAXCONN);
>
> while(1) {
> next unless my $remote_addr = accept(SESSION,SOCK);
> ...additional code here
>
> }
>
> Disregarding any limitations of this code, do I understand that
> accept() spawns another socket with the file handle of SESSION?
Yes that is correct.
> I presume this allows SOCK to go back to listen()ing, and since
> SESSION is already in use, another connection might not be possible
> until SESSION is closed...am I getting ahead of mysefl?
Right there are two things here. The first is the Unix-like socket
library listen(), socket() etc...
You seem to have got that bit OK. But now you can forget it - it's
useful to know but almost nobody ever uses it directly.
The limit of only supporting a single client is a limitation of doing
everything in a single process with blocking IO operations. (The fact
that SESSION is a global variable doesn't help).
If you want multiple concurrent clients you need either to fork() off
a child for each client (within "additional code here") or re-write
the whole thing with a more complex event loop with select().
There are numerous modules on CPAN (and even in standard Perl) to
provide warm fuzzy wrappers around all this low level socket stuff
IO::Socket and even to do the event loops for you.
Even if you are going to use the low-level functions I'd recommend
ditching the Perl4-style global handles.
listen( $SOCK,SOMAXCONN);
while(1) {
next unless my $remote_addr = accept(my $SESSION,SOCK);
...additional code here
}
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