setitimer 定时器

#include <unistd.h>
#include <time.h>
#include <string.h>
#include <math.h>
#include <stdio.h>
#include <curses.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/wait.h>

WINDOW *wtime,*wnumb;
void showtime(int s){
 time_t tt;
 struct tm *t;
 if(s == SIGALRM){
  tt = time(0);
  t = localtime(&tt);
  mvwprintw(wtime,1,1,"%02d:%02d:%02d",t->tm_hour,t->tm_min,t->tm_sec);
  refresh();
  wrefresh(wnumb);
  wrefresh(wtime);
 }
}


int main(){
 struct itimerval val;
 initscr();
 curs_set(0);  //close cursor
 signal(SIGALRM,showtime);
 bzero(&val,sizeof(struct itimerval));
 val.it_value.tv_sec = 0;
 val.it_value.tv_usec = 1;
 val.it_interval.tv_sec = 1;
 wnumb=derwin(stdscr,3,11,(LINES-3)/2,(COLS-11)/2);
 wtime=derwin(stdscr,3,10,0,COLS-10);
 box(wnumb,0,0);
 box(wtime,0,0);
 setitimer(ITIMER_REAL,&val,0);
 refresh();
 wrefresh(wnumb);
 wrefresh(wtime);
 while(1){
  int sum = 0,i;
  for(i = 0;i < 7;i++)
   sum = sum*10 + random()%10;
  mvwprintw(wnumb,1,2,"%07d",sum);
  refresh();
  wrefresh(wnumb);
  wrefresh(wtime);
  usleep(1000000);
 }
 endwin();
 return 1;
}

#include <unistd.h>
#include <time.h>
#include <string.h>
#include <math.h>
#include <stdio.h>
#include <curses.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/wait.h>

WINDOW *wnumb;

int isstop = 0;
void handle(int s){
 if(s == SIGUSR1){
  if(isstop==0)
   isstop = 1;
  else
   isstop = 0;
 }
}
int main(){

 initscr();
 curs_set(0);  //close cursor
 wnumb=derwin(stdscr,3,11,(LINES-3)/2,(COLS-11)/2);
 keypad(wnumb,TRUE);
 keypad(stdscr,TRUE);
 noecho();

 box(wnumb,0,0);
 refresh();
 wrefresh(wnumb);
 if(fork()){
  signal(SIGUSR1,handle);
  while(1){
   if(isstop==1)
   pause();
   int sum = 0,i;
   for(i = 0;i < 7;i++)
    sum = sum*10 + random()%10;
   mvwprintw(wnumb,1,2,"%07d",sum);
   refresh();
   wrefresh(wnumb);
   usleep(1000);
  }
 }else{
  while(1){
   int ch = getch();
   kill(getppid(),SIGUSR1);
  }

 }
 
 endwin();
 return 1;
}