#include <unistd.h>#include <sys/types.h>int main(int argc,char *argv[]){	pid_t child;	printf("getpid=%d\n",getpid());	printf("group id=%d\n",getpgrp());	child=fork();	if(child==0)	{		printf("child group id=%d\n",getpgid(getpid()));		setpgid(0,0);		printf("new group id=%d\n",getpgrp());		exit(0);	}	return 0;}