Enable Terminal Raw Mode

rawmode.c

// Simple snippets to enable raw mode
// stdin is read as long as any key are pressed
// A simple testing function is included
// Note in raw mode "\n" is not interpreted with "\r" carriage return
// All "\n" shall be replaced with "\r\n" for normal effect

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>

struct termios original;

void disableRAWMode(void) {
  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &original) == -1) {
    perror("error occur in function disableRAWMode");
  }
}

void enableRAWMode(void) {
  struct termios raw;
  if (tcgetattr(STDIN_FILENO, &raw) == -1) {
    // STDIN_FILENO is the standard input
    perror("tcgetattr");
  }
  if (tcgetattr(STDIN_FILENO, &original) == -1) {
    perror("tcgetattr");
  }
  atexit(&disableRAWMode); // From <stdlib.h> Execute the function when the
                           // program exits.

  raw.c_lflag &= ~(ECHO | ICANON | ISIG | IEXTEN);
  raw.c_iflag &= ~(IXON | ICRNL | BRKINT | INPCK | ISTRIP);
  raw.c_oflag &= ~(OPOST);
  raw.c_cflag &= ~(CS8);

  //  raw.c_cc[VMIN] = 0;  // what read() returns after timeout
  //  raw.c_cc[VTIME] = 1; // Timeout after 0.1 s

  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) == -1) {
    perror("tcsetattr");
  }
}

int main() {
  enableRAWMode();
	char a = getchar();
	printf("key code: %i\r\n", a);
  return 0;
}