在没有 X11 的情况下获取 Linux 中 Keycode 的 Keymap 等效字符

如何解决在没有 X11 的情况下获取 Linux 中 Keycode 的 Keymap 等效字符

我正在编写一个控制台程序，它在纯文本控制台上运行。我需要同时接收按键和按键释放事件。但我还需要支持非英语语言的键盘布局。我在以下代码中接收键代码以及按下和释放的事件，但我需要根据当前的键盘映射将该键代码转换为其相应的 utf-8 字符。我该怎么办？

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <getopt.h>
#include <signal.h>
#include <fcntl.h>
#include <termios.h>
#include <locale.h>
#include <linux/kd.h>
#include <linux/keyboard.h>
#include <sys/ioctl.h>


int fd;
int oldkbmode;

struct termios old;

#define _(a) (a)

static int
is_a_console(int fd) 
{
    char arg;
    arg = 0;
    return (ioctl(fd,KDGKBTYPE,&arg) == 0
        && ((arg == KB_101) || (arg == KB_84)));
}

static int
open_a_console(const char *fnam) 
{
    int fd;
    /*
     * For ioctl purposes we only need some fd and permissions
     * do not matter. But setfont:activatemap() does a write.
     */
    fd = open(fnam,O_RDWR);
    if (fd < 0 && errno == EACCES)
        fd = open(fnam,O_WRONLY);
    if (fd < 0 && errno == EACCES)
        fd = open(fnam,O_RDONLY);
    if (fd < 0)
        return -1;
    if (!is_a_console(fd)) {
        close(fd);
        return -1;
    }
    return fd;
}

int 
getfd(const char *fnam) 
{
    int fd;
    if (fnam) {
        fd = open_a_console(fnam);
        if (fd >= 0)
            return fd;
        fprintf(stderr,_("Couldnt open %s\n"),fnam);
        exit(1);
    }
    fd = open_a_console("/dev/tty");
    if (fd >= 0)
        return fd;
    fd = open_a_console("/dev/tty0");
    if (fd >= 0)
        return fd;
    fd = open_a_console("/dev/vc/0");
    if (fd >= 0)
        return fd;
    fd = open_a_console("/dev/console");
    if (fd >= 0)
        return fd;
    for (fd = 0; fd < 3; fd++)
        if (is_a_console(fd))
            return fd;
    fprintf(stderr,_("Couldnt get a file descriptor referring to the console\n"));
    exit(1);        /* total failure */
}

static void
get_mode(void) 
{
        char *m;
    if (ioctl(fd,KDGKBMODE,&oldkbmode)) {
        perror("KDGKBMODE");
        exit(1);
    }
    switch(oldkbmode) {
      case K_RAW:
        m = "RAW"; break;
      case K_XLATE:
        m = "XLATE"; break;
      case K_MEDIUMRAW:
        m = "MEDIUMRAW"; break;
      case K_UNICODE:
        m = "UNICODE"; break;
      default:
        m = _("?UNKNOWN?"); break;
    }
    printf(_("kb mode was %s\n"),m);
    if (oldkbmode != K_XLATE) {
        printf(_("[ if you are trying this under X,it might not work\n"
             "since the X server is also reading /dev/console ]\n"));
    }
    printf("\n");
}

static void
clean_up(void) 
{
    if (ioctl(fd,KDSKBMODE,oldkbmode)) {
        perror("KDSKBMODE");
        exit(1);
    }
    if (tcsetattr(fd,&old) == -1)
        perror("tcsetattr");
    close(fd);
}

static void
die(int x) 
{
    printf(_("caught signal %d,cleaning up...\n"),x);
    clean_up();
    exit(1);
}

static void
watch_dog(int x) 
{
    clean_up();
    exit(0);
}


int
main (int argc,char *argv[]) 
{
    const char *short_opts = "haskV";
    const struct option long_opts[] = {
        { "scancodes",no_argument,NULL,'s' },{ "keycodes",'k' },{ NULL,0 }
    };

    int c;
    int show_keycodes = 1;
    struct termios new;
    unsigned char buf[16];
    int i,n;

    setlocale(LC_ALL,"");

    while ((c = getopt_long(argc,argv,short_opts,long_opts,NULL)) != -1) {
        switch (c) {
            case 's':
                show_keycodes = 0;
                break;
            case 'k':
                show_keycodes = 1;
                break;

            case 'h':
            case '?':
                usage();
        }
    }
    if (optind < argc)
        usage();

    fd = getfd(NULL);
    signal(SIGALRM,watch_dog);

    signal(SIGHUP,die);
    signal(SIGINT,die);
    signal(SIGQUIT,die);
    signal(SIGILL,die);
    signal(SIGTRAP,die);
    signal(SIGABRT,die);
    signal(SIGIOT,die);
    signal(SIGFPE,die);
    signal(SIGKILL,die);
    signal(SIGUSR1,die);
    signal(SIGSEGV,die);
    signal(SIGUSR2,die);
    signal(SIGPIPE,die);
    signal(SIGTERM,die);
#ifdef SIGSTKFLT
    signal(SIGSTKFLT,die);
#endif
    signal(SIGCHLD,die);
    signal(SIGCONT,die);
    signal(SIGSTOP,die);
    signal(SIGTSTP,die);
    signal(SIGTTIN,die);
    signal(SIGTTOU,die);

    get_mode();
    if (tcgetattr(fd,&old) == -1)
        perror("tcgetattr");
    if (tcgetattr(fd,&new) == -1)
        perror("tcgetattr");
    new.c_lflag &= ~ (ICANON | ECHO | ISIG);
    new.c_iflag = 0;
    new.c_cc[VMIN] = sizeof(buf);
    new.c_cc[VTIME] = 1;    /* 0.1 sec intercharacter timeout */
    if (tcsetattr(fd,TCSAFLUSH,&new) == -1)
        perror("tcsetattr");
    if (ioctl(fd,show_keycodes ? K_MEDIUMRAW : K_RAW)) {
        perror("KDSKBMODE");
        exit(1);
    }
    printf(_("press any key (program terminates 10s after last keypress)...\n"));
    while (1) {
        alarm(10);
        n = read(fd,buf,sizeof(buf));
        for (i = 0; i < n; i++) {
            if (!show_keycodes)
                printf("0x%02x ",buf[i]);
            else
                printf(_("keycode %3d %s\n"),buf[i] & 0x7f,buf[i] & 0x80 ? _("release")
                                      : _("press"));
        }
        if (!show_keycodes)
            printf("\n");
    }
    clean_up();
    exit(0);
} 

另外，这需要root访问权限，有没有没有X11的更好的方法来做到这一点？我想在所有键上都获得按下和释放事件，包括修饰符。谢谢。