I have a problem. I'm trying to make a simple server where several clients can connect & send me stuff, and it should send everything received by the clients to STDOUT. The problem is that accept() is blocking the I/O, even though I made socket FH non-blocking. How can I either make accept() non-blocking or use a different function to accomplish the same thing without blocking? Here's the code: 
#!/usr/bin/perl

my @sock;
my $numsocks = 0;
my @message;

print "Waiting for client to connect...\n";
use Socket;
socket(FH, PF_INET, SOCK_STREAM, getprotobyname('tcp')) || die $!;
setsockopt(FH, SOL_SOCKET, SO_REUSEADDR, pack("l", 1));
my $sin = sockaddr_in(20000, INADDR_ANY);
bind(FH, $sin) || die $!;
listen(FH, SOMAXCONN);
my $read = '';
vec($read, fileno(FH), 1) = 1;
select(FH);
$| = 1;
select(STDOUT);

while (1) {
    #this is where it blocks
    if ($cn = accept($sock[$numsocks], FH)) {
            my($port,$iaddr) = sockaddr_in($cn);
            my $name = gethostbyaddr($iaddr,AF_INET);
            print "Connection from $name (", inet_ntoa($iaddr), ") on 
+port $port\n";
        vec($read, fileno($sock[$numsocks]), 1) = 1;
        $numsocks++;
        select($sock[$numsocks-1]);
        $| = 1;
        select(STDOUT);
        $| = 1;
    }
    #uh.. i probably messed up somewhere below.. please excuse its slo
+ppiness : )
    $read = '';
    for($i=0; $i<$numsocks; $i++) {
        vec($read, fileno($sock[$i]), 1) = 1;
    }
    select($readx=$read,undef,undef,undef);
    for($i=0; $i<$numsocks; $i++) {
        print "Checking socket $i...\n";
        if (vec($readx, fileno($sock[$i]), 1)) {
            sysread $sock[$i], $a, 10;
            print "$a";
            #my @lines = split(/\n/, $a);
            #if (@lines > 0) {
            #    $lines[0] = $message[$i] . $lines[0];
            #    $message[$i] = "";
            #}
            #$message[$i] .= pop(@lines);
            #foreach $ii (@lines) {
            #    print "$lines[$ii]\n";
            #}
            print "Read socket $i..\n";
        }
    }
}
exit;

[download]

Edit 2001-03-16 by tye to change title (was "Zip")

In reply to accept() on non-blocking socket still hangs by Zip

Title:
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, details, 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, summary, 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.