use IO::Socket;
use POSIX qw/BUFSIZ/;

# Create an IO::Select object, and ask it to look at $sock.
my $s = IO::Select->new();
$s->add($sock);

# Continue to read on $sock until things are quiet for
# at least one second.

my $message;
while ($s->can_read(1)) {
    my $buffer;
    my $bytes_read = sysread($sock,$buffer,BUFSIZ);
    unless ($bytes_read) {
        # Socket just closed, clean it up...
    }
    $message .= $buffer;
}