#include <unistd.h>#include <sys/types.h>#include <sys/wait.h>#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <math.h>int main(void){	pid_t child;	/* 創建子進程 */	if((child=fork())==-1)	{		printf("Fork Error : %s\n", strerror(errno));		exit(1);	}	else 		if(child==0) // 子進程		{			printf("I am the child: %d\n", getpid());			exit(0);		}		else        //父進程		{			printf("I am the father:%d\n",getpid());			return 0;		}}