IO进程线程DAY5

 

 僵尸

#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, const char *argv[])
{
	pid_t cpid=fork();
	if(cpid>0)
	{
		while(1)
		{
			printf("this is parent\n");
			sleep(1);
		}
	}
	else if(0==cpid)
	{
		exit(0);
	}
	else
	{
		perror("fork");
		return -1;
	}
	return 0;
}

孤儿

#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, const char *argv[])
{
	pid_t cpid=fork();
	if(0==cpid)
	{
		while(1)
		{
			printf("this is child %d %d\n",getppid(),getpid());
			sleep(1);
		}
	}
	else if(cpid>0)
	{
		exit(0);
	}
	else
	{
		perror("fork");
		return -1;
	}
	return 0;
}

守护

#include 
#include 
#include 
#include 
#include 
#include 
int main(int argc, const char *argv[])
{
	if(fork()==0)
	{
		setsid();
		chdir("/");
		umask(0);
		for(int i=0;i