//-----------------------------------------------------------------
// list_68.c
//    DOS(conio.h)上でのkbhit()を再現
//-----------------------------------------------------------------
#include <stdio.h>
#include <unistd.h>
#include <termios.h>
#include <sys/time.h>
//-----------------------------------------------------------------
void init_keyboard();
void close_keyboard();
int kbhit();
int readch();
//-----------------------------------------------------------------
static struct termios init_tio;

int main()
{
    int ch,count=0;
    init_keyboard();
    while(ch != 'q') {
        if(kbhit()) {
            ch = readkey();
            printf("you hit %X : %c\n",ch,ch);
        }
        count++;
    }
    close_keyboard();
    
    printf("final count = %d\n",count);
    return 0;
}
//-----------------------------------------------------------------
// 初期入力状態の取得
//-----------------------------------------------------------------
void init_keyboard()
{            
    tcgetattr(0,&init_tio);
}
void close_keyboard()
{            
    tcsetattr(0,TCSANOW,&init_tio);
}
//-----------------------------------------------------------------
// kbhit
//-----------------------------------------------------------------
int kbhit()
{
    struct termios tio;
    struct timeval tv;
    fd_set rfds;
    // set up terminal
    memcpy(&tio,&init_tio,sizeof(struct termios));
    tio.c_lflag &= ~(ICANON);
    tcsetattr(0,TCSANOW,&tio);
    // do not wait
    FD_ZERO(&rfds);
    FD_SET(0,&rfds);
    tv.tv_usec = 0;
    tv.tv_sec  = 0;
    select(1,&rfds,NULL,NULL,&tv);
    // back to initial terminal mode
    tcsetattr(0,TCSANOW,&init_tio);
    return (FD_ISSET(0,&rfds)?1:0);
}
//-----------------------------------------------------------------
// キー入力
//-----------------------------------------------------------------
int readkey()
{
    int ch;
    struct termios tio;
    // set up terminal
    memcpy(&tio,&init_tio,sizeof(struct termios));
    tio.c_lflag &= ~(ICANON | ECHO);
    tcsetattr(STDIN_FILENO,TCSANOW,&tio);
    // input key
    read(0,&ch,1);
    // back to initial terminal mode
    tcsetattr(0,TCSANOW,&init_tio);
    return ch;
}