int main(){
    initscr();
    clear();
    move(10,20);
    addstr("hello word");
    move(LINES - 1,0);
    getch();
    endwin();
}

int main(){
    int i ;
    initscr();  // 初始化
    clear() ;  // 清屏
    for( i = 0;i < LINES;++i){
        move(i,i+1);
        if (i %2 == 1)
            standout();  // 反色
        addstr("hello word");
        if (i % 2 == 1)
            standend();  // 恢复
    }
    refresh();  // 让屏幕按照你的意图显示  立即刷新缓存的意思
    getchar();  // 等待用户输入
    endwin();   // 恢复终端状态
}

void wakeup(int);
int main(){
    printf("about to sleep for 4 seconds\n");
    signal(SIGALRM,wakeup);  // 信号处理的三种模式 还记得吗
    alarm(4);                // 当时间到了以后，内核发送SIGALRM到该进程
    pause(); // 挂起，等待信号。 不仅仅是SIGALRM时钟信号，别的信号也可以唤醒，或者死亡
    printf(" has end");
}

void wakeup(int signum){
    printf(("Alarm received from kernel\n"));
}

int main(){
    void countdown(int);

    // SIGALRM 真实时间
    signal(SIGALRM,countdown);
    if (set_ticker(500) == -1 ){
        perror("set_ticker");
    } else{
        while (1){
            pause();
        }
    }
    return 0;
}

int set_ticker(int n_msecs){
    struct itimerval new_timeset;
    long n_sec,n_usecs;

    n_sec = n_msecs / 1000 ;
    n_usecs = ( n_msecs % 1000 ) * 1000L ;

    /**
     * 设置初始时间和间隔时间
     * 每个时间都是由两个值组成   秒 与 毫秒
     */
     // 间隔时间
    new_timeset.it_interval.tv_sec  = n_sec;        /* set reload  */
    new_timeset.it_interval.tv_usec = n_usecs;      /* new ticker value */
    // 初始时间
    new_timeset.it_value.tv_sec     = n_sec  ;      /* store this   */
    new_timeset.it_value.tv_usec    = n_usecs ;     /* and this     */

    return setitimer(ITIMER_REAL, &new_timeset, NULL);

}

void countdown(int signum){
    static int num = 10;
    printf("%d ..",num --);
    fflush(stdout);
    if(num < 0){
        printf("DONE ! \n");
        exit(0);
    }
}

#define INPUTLEN 100
int main(){
    void inthandler(int);
    void quithandler(int);
    char input[INPUTLEN];
    int nchars;

    signal(SIGINT,inthandler);
    signal(SIGQUIT,quithandler);

    do{
        printf("\nType a massage\n");
        nchars = read(0,input,(INPUTLEN - 1));
        if (nchars == -1){
            perror(" read returned an error");
        } else{
            input[nchars] = '\0';
            printf("You typed: %s",input);
        }
    } while (strncmp(input,"quie",4) != 0);
    return 0;
}

void inthandler(int s){
    printf(" Received signal %d .. witing\n",s);
    sleep(2);;
    printf("leaving inthandler \n");
}

void quithandler(int s){
    printf(" Received signal %d .. witing\n",s);
    sleep(2);;
    printf("leaving inthandler \n");
}

#define INPUTLEN 100
int main(){
    struct sigaction newhandler;
    sigset_t blocked;
    void inthandler();
    char x[INPUTLEN];

    newhandler.sa_handler = inthandler;     // 老模式
    newhandler.sa_flags = SA_RESETHAND;   // 函数调用时重置
    
    // 阻塞设置 这个在下章中详解
    sigemptyset(&blocked);
    sigaddset(&blocked,SIGQUIT);
    newhandler.sa_mask = blocked;

    if (sigaction(SIGINT,&newhandler,NULL) == -1){
        perror("sigaction");
    } else{
        while (1){
            fgets(x,INPUTLEN,stdin);
            printf("input:%s",x);
        }
    }

    return 0;
}

void inthandler(int s){
    printf("Callen with signal %d \n",s);
    sleep(s);
    printf("done handing signal %d \n",s);
}

int main() {
    sigset_t sigs, prevsigs;
    sigemptyset(&sigs);   // 设为空
    sigaddset(&sigs, SIGINT);    // ctr-v信号加入其中
    sigaddset(&sigs, SIGQUIT);   // ctrl-\信号加入其中
    sigprocmask(SIG_BLOCK, &sigs, &prevsigs);    //将信号列表的中的信号设为阻塞状态
    sigprocmask(SIG__SET, *prevsigs, NULL);  //  恢复为之前状态
}