我创建了一个Perl脚本，它在我的服务器上打开一个新的套接字。当我用telnet连接到套接字并写（和接收）一些东西时，连接关闭。

#!/usr/bin/perl
use strict;
use warnings;
use IO::Socket;
use IO::Socket::INET;
$| = 1;
my $sock = IO::Socket::INET->new(Listen    => 5,
                                 LocalAddr => 'localhost',
                                 LocalPort => 9000,
                                 Reuse => 1,
                                 Proto     => 'tcp');
die "Socket not created $!\n" unless $sock;
print "Server waiting for connections\n";
while(1)
{
    # waiting for a new client connection
    my $client_socket = $sock->accept();

    # get information about a newly connected client
    my $client_address = $client_socket->peerhost();
    my $client_port = $client_socket->peerport();
    print "Connection from $client_address:$client_port\n";

    # read up to 1024 characters from the connected client
    my $data = "";
    $client_socket->recv($data, 1024);
    chomp($data);
    print "Data: $data\n";

    # write response data to the connected client
    my $dataok = "OK";
    $client_socket->send("$dataok\n");
    $client_socket->send("$data\n");
    if($data == 500){
        close($sock);
        exit(); 
    }
    elsif($data eq "Close\r") {
        close($sock);
        exit();
    }
}

字符串
我的telnet会话：

telnet localhost 9000
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
e //(Sent)
e //(Received)
Connection closed by foreign host.

型
为什么我的脚本关闭了连接？提前感谢