How can I read only one character at a time?
Answer / chaitanya
This question is usually asked by people who are testing their server with telnet, and want it to process their keystrokes one character at a time. The correct technique is to use a psuedo terminal (pty). More on that in a minute.
You can have your server send a sequence of control characters: 0xff 0xfb 0x01 0xff 0xfb 0x03 0xff 0xfd 0x0f3, which translates to IAC WILL ECHO IAC WILL SUPPRESS-GO-AHEAD IAC DO SUPPRESS-GO-AHEAD. For more information on what this means, check out std8, std28 and std29. Roger also gave the following tips:
o This code will suppress echo, so you'll have to send the characters the user types back to the client if you want the user to see them.
o Carriage returns will be followed by a null character, so you'll have to expect them.
o If you get a 0xff, it will be followed by two more characters. These are telnet escapes.
Use of a pty would also be the correct way to execute a child process and pass the i/o to a socket.
Is This Answer Correct ? | 0 Yes | 0 No |
When will my application receive SIGPIPE?
How do I get the port number for a given service?
How do I properly close a socket?
Is there any advantage to handling the signal, rather than just ignoring it and checking for the EPIPE error? Are there any useful parameters passed to the signal catching function?
How to find other end of unix socket connection?
Why do we need socket programming?
What is a socket file?
What is socket address?
Can multiple clients connect to same socket?
What is sae socket?
What is with the second parameter in bind()?
What exactly does SO_KEEPALIVE do?