Get char from stdin without pressing enter.

getch.c

#include <stdio.h>
#include <termios.h>

int getch(void) {
  int ch;
  struct termios oldt;
  struct termios newt;
  
  tcgetattr(STDIN_FILENO, &oldt); /*store old settings */
  newt = oldt; /* copy old settings to new settings */
  newt.c_lflag &= ~(ICANON | ECHO); /* make one change to old settings in new settings */
  
  tcsetattr(STDIN_FILENO, TCSANOW, &newt); /*apply the new settings immediatly */
  
  ch = getchar(); /* standard getchar call */
  
  tcsetattr(STDIN_FILENO, TCSANOW, &oldt); /*reapply the old settings */
  
  return ch; /*return received char */
}

int main() {
  while (1) {
    int ch = getch();
    printf("Get char: %d\n", ch);
  }

  return 0;
}

// Tested on Ubuntu 14.04
// Refer to: http://www.cplusplus.com/forum/unices/18395/