How to use pseudo-terminals in Linux with C?

c linux pty
Irresponsible Newb picture Irresponsible Newb · Dec 4, 2011 · Viewed 15.2k times · Source

I'm trying to figure out how to use pseudo-terminal's in linux, essentially I want to create a telnetd clone, something I mentioned in an earlier question.

I understand the concept of master and slave terminal, and I have a basic grasp on how to use syscalls in C.

My question concerns the next step after opening a slave / master file descriptor. How to I launch getty in the slave? Are there any good resources on the net for using the forkpty(), openpty(),or another API?

Some examples in C would help. This was a very similar question, but no one really provided any examples.

Answer

sarnold picture sarnold · Dec 4, 2011

Advanced Programming in the Unix Environment, 2nd Edition has a superb chapter on the pseudo-terminal layer available in Linux. The best part is the source code which contains a pty driver and very clearly demonstrates how to use the pty interfaces. (The pty program it builds is useful in its own right if you want to drive a terminal-only program programmatically but don't wish to use expect(1).)

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