Unbuffered I/O in ANSI C

Question

For the sake of education, and programming practice, I\'d like to write a simple library that can handle raw keyboard input, and output to the terminal in \'real time\'.

Answer 1

Sticking with Standard C as much as possible is a good idea, but you are not going to get very far with your adopted task using just Standard C. The mechanisms to obtain characters from the terminal one at a time are inherently platform specific. For POSIX systems (MacOS X), look at the header. Older systems use a vast variety of headers and system calls to achieve similar effects. You'll have to decide whether you are going to do any special character handling, remembering that things like 'line kill' can appear at the end of the line and zap all the characters entered so far.

For Windows, you'll need to delve into the WIN32 API - there is going to be essentially no commonality in the code between Unix and Windows, at least where you put the 'terminal' into character-by-character mode. Once you've got a mechanism to read single characters, you can manage common code - probably.

Also, you'll need to worry about the differences between characters and the keys pressed. For example, to enter 'ï' on MacOS X, you type option-u and i. That's three key presses.