What does it mean that the terminal displays escape character is'^]'after the telnet peer port?

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Begin with topic , Sometimes we want to confirm whether some ports on the opposite end can be connected normally , such as tcp 80、443、21、25、8080 wait , here tcp 80、443 The ports are generally good to verify whether they can be connected normally , Whether it's a mobile phone or a computer , We open the browser and input the colon in English after the URL “:”, After connecting the port number, you can test , For example ：

visit www.baidu.com The port number access example is added later

After the above test demonstration , Actually visit www.baidu.com:443 Will jump to https://www.baidu.com, Here because https The protocol uses well-known tcp The port number is 443, I won't go into details here , Interested in Baidu for a while .

But for example, some mail service ports are not easy to test , You also need to download some software that supports connecting to the peer mail service , It will be very trouble ; And the services used for the port number are different , You also need to download the corresponding client software to test , This will greatly reduce the efficiency of our work , Here we can use a well-known remote terminal protocol , Yes, it is telnet, I won't explain it to you here telnet The principle and method of use , You can go to Baidu , Articles on the Internet 、 There are many tutorials to use ; For some small partners who use the software for the first time , Will feel confused , After entering the command , The terminal displays a lot of things , And there is no formal text to describe whether the connection is successful , As shown below ：

The place where the mosaics are made is ip, Because of the production environment IP, In order to ensure safety, just code , It doesn't affect the view in general , If that doesn't work , I suggest you break the steel bars .

As shown in the example above , front 2 That's ok , Only primary schools have had English classes , It's probably understandable , I don't understand it doesn't matter , Baidu translation , Tencent can translate ; But the third line doesn't work , What the hell is this , What I'm talking about here is not English. I can't understand it , Because it is translated into Chinese , You can't understand , Translate into Chinese ：“ The escape character is “^]”.” yes , Chinese characters can be understood , But do you know what it means ？ The connection is successful ？ The connection is still not successful ？ Who knows , It doesn't talk to people .

Okay , No kidding , Make a noise , Play and play , You have to do the right thing , In you telnet When the opposite end has some specified ports , The terminal displays this prompt , It indicates that you have successfully connected to the opposite port , Then it will remind you , You press... On the keyboard ctrl and ] You can exhale telnet The command line , After entering the command line, you can connect to a site under this port （open）、 Send special characters （telnetsend）、 Print status information （status）, Or close the connection （close）, In or out （quit） Fine .

In fact, in a word, when you telnet A site or ip Add The port number appears Escape character is '^]' It means that you have successfully connected to the opposite port .