How do I unbuffer input with the D programming language in linux?

Question

By default you can't get the terminal input in Unix without waiting for the User to press enter. How can I get the input instantly? I am using gdc on debian Linux so I can't use ncurses. Thanks.

"I am using gdc on debian Linux so I can't use ncurses" What makes you think that, exactly? — Ben Voigt, Mar 02 '14 at 18:39
http://stackoverflow.com/questions/1630597/how-to-use-a-c-library-from-d — Ben Voigt, Mar 02 '14 at 22:52
I was wondering the same question... Ncurses are now available on Windows too. — DejanLekic, Mar 03 '14 at 12:51

score 3 · Accepted Answer · answered Mar 02 '14 at 19:05

ncurses is a good solution that should work on almost any linux installation with any compiler...

But if you don't want to use ncurses, there's a few other options:

My terminal.d offers it and works on most terminals, but not as many as ncurses (I'd say I cover 98% of typical setups but there's a LOT of variations out there and i didn't try to be as comprehensive as ncurses): https://github.com/adamdruppe/misc-stuff-including-D-programming-language-web-stuff/blob/master/terminal.d

Look near the bottom of the file for a version(Demo) void main(). RealTimeConsoleInput gives you an event loop with instant input and other info if you want it (mouse, resize, etc.).

You can also just change the terminal mode with the proper tcgetattr and tcsetattr calls and then do everything else normally. You'll want to import core.sys.posix.termios; and import core.sys.posix.unistd; for the functions, then the rest is done the same as in C.

Here's how to do that:

 termios old;
 tcgetattr(1, &old);
 scope(exit) tcsetattr(1, TCSANOW, &old); // put the terminal back to how it was
 auto n = old;
 n.c_lflag &= ~ICANON; // turn off canonical mode
 tcsetattr(1, TCSANOW, &n); // do the change

Then you can use the input instantly.

How do I unbuffer input with the D programming language in linux?

1 Answers1