Linux implementation of <conio.h>

This project implements the Windows-specific functions _getch() and _kbhit() from conio.h. These functions are used to read characters from stdin, without the user having to press enter, with the option to do it in a non-blocking way, which can be used to detect keypresses without having to "pause" the application while waiting for input.

Cross platform

Despite being an implementation of a Windows API for Linux, this project also works for Windows. The only function which is "implemented" for Windows (ie. adds onto the already existing functionality) is:

int getch_noblock(); 

which is a non-blocking version of _getch(), which returns EOF if no character can be read from stdin.

Usage

• Add the linux_conio.h and linux_conio.cpp files to your project
• Include the linux_conio.h header file in your project
• Call enable_conio_mode() every time before the library is used (if conio mode is currently disabled)
• Use _getch(), _kbhit() and/or getch_noblock() as you would normally
• Call disable_conio_mode() when your program is closing to restore the console settings.

Compiling

This project compiles on any modern C++ compiler for either Linux or Windows. In this example I will use gcc To compile the project and run the test cases, run:

g++ test.cpp linux_conio.cpp -o conio.out
./conio.out

Limitations

This is not a full implementation of conio.h, it only implements _getch() and _kbhit(), which are the most important functions from conio.h, and also the hardest to implement on Linux.

To achieve this functionality on Linux, the application changes the terminal settings, which has some caveats:

• enable_conio_mode() needs to be called before any functionality is used
• disable_conio_mode() needs to be called if you want to take normal input with std::cin
• disable_conio_mode needs to be called when the program exits, else the console will glitch.
• When a terminating signal which can not be handled (eg. SIGKILL or SIGSTOP) is sent, conio mode does not get automatically disabled and will glitch the console. (SIGINT, SIGTERM, SIGQUIT and SIGTSTP is properly handled and cleaned up though)

Future work

• Implement more functions from conio.h (Not very important)