debian linux c++ how to make key stroke brake infinit loop - c++

Question

I want a infinit loop to break when I press "q" key on my keyboard.
Problems I did'nt realize: standard getchar waits for the user to make an
input and press enter, which halt the execution of the loop there.
I got around the "enter" problem, but the loop still halts and waits for the input.
here is my code:
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <termios.h>
int getch(void); // Declare of new function
int main (void) { char x;
do
{
if (x = getch())
printf ("Got It! \n!);
else
{
delay(2000);
printf ("Not yet\n!);
}
}while x != 'q');
return 0;
}
int getch(void)
{
int ch;
struct termios oldt;
struct termios newt;
tcgetattr(STDIN_FILENO, &oldt);
newt = oldt;
newt.c_lflag &= ~(ICANON | ECHO);
tcsetattr(STDIN_FILENO, TCSANOW, &newt);
ch = getchar();
tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
return ch;
}

Answer 1

You could read them from the device:
#define INPUT_QUEUE "/dev/input/event0"
#define EVENT_LEN 16
void readEventLine(FILE * in, char * data) { //read input key stream
int i;
for(i = 0; i <= 15; i++) { //each key press will trigger 16 characters of data, describing the event
data[i] = (char) fgetc(in);
}
}
int readKeyPress() {
FILE * input;
char data[EVENT_LEN];
input = fopen(INPUT_QUEUE, "r+");
readEventLine(input, data);
}
Just call something like this instead of your getch.
Adapted from http://www.cplusplus.com/forum/unices/8206/

Answer 2

I had to do following to make it work correctly, thanks for input!!
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
int getch(void); // Declare of new function
int main (void)
{
char x;
do
{
x = getch();
if (x != EOF)
{
printf ("\r%s\n", "Got something:");
printf ("it's %c!",x); // %c - for character %d - for ascii number
}else
{
delay(2000);
printf ("Not yet\n!);
}
}while x != 'q');
return 0;
}
int getch(void)
{
int ch;
struct termios oldt;
struct termios newt;
long oldf;
long newf;
tcgetattr(STDIN_FILENO, &oldt); /* Store old settings */
newt = oldt;
newt.c_lflag &= ~(ICANON | ECHO); /* Make one change to old settings in new settings */
tcsetattr(STDIN_FILENO, TCSANOW, &newt); /* Apply the changes immediatly */
oldf = fcntl(STDIN_FILENO, F_GETFL, 0);
newf = oldf | O_NONBLOCK;
fcntl(STDIN_FILENO, F_SETFL, newf);
ch = getchar();
fcntl(STDIN_FILENO, F_SETFL, oldf);
tcsetattr(STDIN_FILENO, TCSANOW, &oldt); /* Reapply the old settings */
return ch;
}