示例:

[root@localhost ~]# telnet 192.168.33.1 80
Trying 192.168.33.1...
Connected to 192.168.33.1.
Escape character is '^]'.
helo
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>501 Not Implemented</title>
</head><body>
<h1>Not Implemented</h1>
<p>helo to /index.html not supported.<br />
</p>
<hr>
<address>Apache/2.4.9 (Win32) PHP/5.5.12 Server at demo1.com Port 80</address>
</body></html>
Connection closed by foreign host.

用法: 

telnet [-4] [-6] [-8] [-E] [-L] [-S tos] [-a] [-c] [-d] [-e char] [-l user]

[-n tracefile] [-b hostalias ] [-r] 

 [host-name [port]]