kitty keyboard protocol demo

kkp.c

#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

struct termios orig_termios;

void reset_terminal() {
  printf("\033[<u\033[?25h"); // 退出 KKP 并显示光标
  tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios);
  fflush(stdout);
}

void set_terminal() {
  tcgetattr(STDIN_FILENO, &orig_termios);
  atexit(reset_terminal);

  struct termios raw = orig_termios;
  raw.c_lflag &= ~(ECHO | ICANON | ISIG);
  tcsetattr(STDIN_FILENO, TCSANOW, &raw);

  printf("\033[?25l\033[>11u"); // 隐藏光标开启 KKP
  fflush(stdout);
}

const char *get_mods(int m) {
  static char buf[32];
  m -= 1; // modifier = mask + 1
  snprintf(buf, sizeof(buf), "%s%s%s%s", (m & 1) ? "Shift " : "",
           (m & 2) ? "Alt " : "", (m & 4) ? "Ctrl " : "",
           (m & 8) ? "Super " : "");
  return buf;
}

int main() {
  set_terminal();
  printf("Kitty Keyboard Protocol Demo. Press 'q' or 'ESC' to exit.\r\n");

  while (1) {
    unsigned char buf[64];
    int n = read(STDIN_FILENO, buf, sizeof(buf) - 1);
    if (n <= 0)
      continue;
    buf[n] = '\0';

    if (buf[0] == 27 && n > 1 && buf[1] == '[') {
      int code = 0, mods = 1, event = 1;
      char cmd = buf[n - 1];

      const char *evtname[] = {"", "PRESS", "REPEAT", "RELEASE"};
      if (cmd == 'u' || (cmd >= 'A' && cmd <= 'Z')) {
        if (sscanf((char *)buf + 2, "%d;%d:%d", &code, &mods, &event) < 3)
          if (sscanf((char *)buf + 2, "%d;%d", &code, &mods) < 2)
            sscanf((char *)buf + 2, "%d", &code);

        if (cmd == 'u') {
          printf("[%7s] Key: %-10d | Mods: %s\n",
                 evtname[event > 3 ? 0 : event], code, get_mods(mods));
          if (code == 'q' || code == 27)
            break;
        } else if (cmd >= 'A' && cmd <= 'Z') {
          const char *arrow[] = {"UP", "DOWN", "RIGHT", "LEFT"};
          printf("[%7s] Key: %-10s | Mods: %s\n",
                 evtname[event > 3 ? 0 : event], arrow[cmd - 'A'],
                 get_mods(mods));
        }
      } else {
        printf("Other CSI: %s\r\n", buf + 1);
      }
    } else if (buf[0] == 27 && n == 1) {
      printf("Legacy ESC pressed.\r\n");
      break;
    } else {
      printf("Legacy Char: %c (%d)\r\n", buf[0] >= 32 ? buf[0] : '.', buf[0]);
      if (buf[0] == 'q')
        break;
    }
  }
  return 0;
}