1 /* 2 C non-blocking keyboard input 3 http://stackoverflow.com/questions/448944/c-non-blocking-keyboard-input 4 */ 5 6 #include <stdlib.h> 7 #include <string.h> 8 #include <sys/select.h> 9 #include <termios.h> 10 #include <unistd.h> 11 #include "getch.h" 12 13 struct termios orig_termios; 14 15 void reset_terminal_mode() 16 { 17 tcsetattr(0, TCSANOW, &orig_termios); 18 } 19 20 void set_conio_terminal_mode() 21 { 22 struct termios new_termios; 23 24 /* take two copies - one for now, one for later */ 25 tcgetattr(0, &orig_termios); 26 memcpy(&new_termios, &orig_termios, sizeof(new_termios)); 27 28 /* register cleanup handler, and set the new terminal mode */ 29 atexit(reset_terminal_mode); 30 cfmakeraw(&new_termios); 31 new_termios.c_oflag |= OPOST; 32 tcsetattr(0, TCSANOW, &new_termios); 33 } 34 35 int kbhit() 36 { 37 struct timeval tv = { 0L, 0L }; 38 fd_set fds; 39 FD_ZERO(&fds); // not in original posting to stackoverflow 40 FD_SET(0, &fds); 41 return select(1, &fds, NULL, NULL, &tv); 42 } 43 44 int getch() 45 { 46 int r; 47 unsigned char c; 48 if ((r = read(0, &c, sizeof(c))) < 0) { 49 return r; 50 } else { 51 return c; 52 } 53 } 54 55 #if 0 56 int main(int argc, char *argv[]) 57 { 58 set_conio_terminal_mode(); 59 60 while (!kbhit()) { 61 /* do some work */ 62 } 63 (void)getch(); /* consume the character */ 64 } 65 #endif 66
