setgid_sample.c

创建守护进程

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>

int main(int argc,char *argv[])
{
	pid_t child;
	child=fork();
	if(child==0)
	{
		printf("old group id=%d\n",getpgrp());
		setpgid(0,atoi(argv[1]));
		printf("new group id=%d\n",getpgrp());
		exit(0);
	}
	return 0;
}