Detect Keyboard Event in C

Question

How can I detect keyboard event in C language without using third party libraries? Should I use signal handling?

Answer 1

There's not a standard way, but these should get you started.

Windows:

getch();

Unix:

Use this code from W. Richard Stevens' Unix Programming book to set your terminal in raw mode, and then use read().

static struct termios   save_termios;
static int              term_saved;

int tty_raw(int fd) {       /* RAW! mode */
    struct termios  buf;

    if (tcgetattr(fd, &save_termios) < 0) /* get the original state */
        return -1;

    buf = save_termios;

    buf.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
                    /* echo off, canonical mode off, extended input
                       processing off, signal chars off */

    buf.c_iflag &= ~(BRKINT | ICRNL | ISTRIP | IXON);
                    /* no SIGINT on BREAK, CR-toNL off, input parity
                       check off, don't strip the 8th bit on input,
                       ouput flow control off */

    buf.c_cflag &= ~(CSIZE | PARENB);
                    /* clear size bits, parity checking off */

    buf.c_cflag |= CS8;
                    /* set 8 bits/char */

    buf.c_oflag &= ~(OPOST);
                    /* output processing off */

    buf.c_cc[VMIN] = 1;  /* 1 byte at a time */
    buf.c_cc[VTIME] = 0; /* no timer on input */

    if (tcsetattr(fd, TCSAFLUSH, &buf) < 0)
        return -1;

    term_saved = 1;

    return 0;
}


int tty_reset(int fd) { /* set it to normal! */
    if (term_saved)
        if (tcsetattr(fd, TCSAFLUSH, &save_termios) < 0)
            return -1;

    return 0;
}