父子进程

父子进程

#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
int main(void)
{
	int i=0,j=0,k=0,n=0;;
	pid_t pid[5];
	pid_t pid_d[5];
	pid_t pid_d_cpy[5];
	pid_t pid_cpy[5];
	pid_t pi;
	int *status;
	printf("pid=%d ppid=%d\n",getpid(),getppid());
_go:
	pid[j]=fork();
	if(pid[j]==0)
	{
			printf("i=%d pid=%d ppid=%d\n",i,getpid(),getppid());
_DOT:
			pid_d[k]=fork();
			if(pid_d[k]==0)
			{
					printf("i=%d pid=%d ppid=%d\n",i,getpid(),getppid());
					sleep(1);
			}
			else if(pid_d[k]>0)
			{
					k++;
					if(k<5)
					{
							goto _DOT;
					}
					for(n=0;n<k;n++)
					{
						if(pid_d[n]>pid_d[n+1])
						{
							pi=pid_d[n];
							pid_d[n]=pid_d[n+1];
							pid_d[n+1]=pi;
						}
					}
					waitpid(pid_d[0],status , 0);
					waitpid(pid_d[1],status , 0);
					waitpid(pid_d[2],status , 0);
					waitpid(pid_d[3],status , 0);
					waitpid(pid_d[4],status , 0);
			}
	}
	else if(pid[j]>0)
	{
			i++;
			j++;
			if(i<5)
			{
					goto _go;
			}
			for(n=0;n<i;n++)
			{
				if(pid[n]>pid[n+1])
				{
					pi=pid[n];
					pid[n]=pid[n+1];
					pid[n+1]=pi;
				}
			}
			waitpid(pid[0],status , 0);
			waitpid(pid[1],status , 0);
			waitpid(pid[2],status , 0);
			waitpid(pid[3],status , 0);
			waitpid(pid[4],status , 0);
	}
	printf("pid=%d will exit\n",getpid());
	return 0;
}