use IO::Socket::UNIX;

$SIG{INT} = sub { unlink "/tmp/sock" };

$srv = IO::Socket::UNIX->new(Local=>"/tmp/sock", Listen=>1);
while ($sock = $srv->accept) {
  $sock->blocking(0);
  for(1..999){
    $sock->syswrite(sprintf "%03d %s\n", $_, "=" x ($_/10));
  }
  $sock->close;
}

##</code><code>##

use IO::Socket::UNIX;
use IO::Select;

$SIG{INT} = sub { unlink "/tmp/sock" };

$srv = IO::Socket::UNIX->new(Local=>"/tmp/sock", Listen=>1);
while ($sock = $srv->accept) {
  $sock->blocking(0);
  $sel = IO::Select->new;
  $sel->add($sock);
  for(1..999){
    do { @ready = $sel->can_write(1) } until @ready;
    $ready[0]->print(sprintf "%03d %s\n", $_, "=" x ($_/10));
  }
  $sock->close;
}