OS X - Keypress in an if statement - c++

Question

I am quite new to C++ programming and using Mac as a computer.
I've been searching around the internet for a while now but I can't still find a good solution for my problem.
I am making a project with the Keyboard Arrows, but I don't know how to make the Keypress function in an if statement.
So the solution I am searching for is:
if (up arrow is pressed) {
std::cout << it worked! << std::endl;
}
Information:
LLVM Compiler, Xcodes command line tool, Unix, OS X-Sierra
Thank you for the help.

Answer 1

Well I couldn't get the code in the other answer to work, not sure what's different since I'm also running Sierra. But I converted it to using tcsetattr. The point of that call is to put the terminal in raw mode, such that it sends key presses directly. If you don't do that it won't send anything until you press enter.
#include <stdio.h>
#include <termios.h>
#include <unistd.h>
static struct termios savemodes;
static int havemodes = 0;
int tty_break(void)
{
struct termios modmodes;
if (tcgetattr(STDIN_FILENO, &savemodes) < 0)
return -1;
havemodes = 1;
modmodes = savemodes;
cfmakeraw(&modmodes);
return tcsetattr(STDIN_FILENO, TCSANOW, &modmodes);
}
int tty_getchar(void)
{
return getchar();
}
int tty_fix(void)
{
if(!havemodes)
return 0;
return tcsetattr(STDIN_FILENO, TCSANOW, &savemodes);
}
int
main(int argc, char *argv[])
{
int i;
if(tty_break() != 0)
return 1;
for(i = 0; i < 10; i++)
printf(" = %d\n", tty_getchar());
tty_fix();
return 0;
}

Answer 2

I have put the code which I linked to in the comments together into a single program so you can see how it works.
#include <stdio.h>
#include <sgtty.h>
static struct sgttyb savemodes;
static int havemodes = 0;
int tty_break()
{
struct sgttyb modmodes;
if(ioctl(fileno(stdin), TIOCGETP, &savemodes) < 0)
return -1;
havemodes = 1;
modmodes = savemodes;
modmodes.sg_flags |= CBREAK;
return ioctl(fileno(stdin), TIOCSETN, &modmodes);
}
int tty_getchar()
{
return getchar();
}
int tty_fix()
{
if(!havemodes)
return 0;
return ioctl(fileno(stdin), TIOCSETN, &savemodes);
}
main()
{
int i;
if(tty_break() != 0)
return 1;
for(i = 0; i < 10; i++)
printf(" = %d\n", tty_getchar());
tty_fix();
return 0;
}
You can compile it simply with:
clang main.c -o main
and run it with:
./main
You will see that the ↑ (Up Arrow) key causes the following codes:
27 (Escape)
91
65
Note the code is not mine - it is entirely extracted from the C-FAQ I mentioned above.