/****************** * fifo_w_test_2.c* ******************/#include <sys/types.h>#include <sys/stat.h>#include <errno.h>#include <fcntl.h>#define FIFO_SERVER "/tmp/fifoserver"main(int argc,char** argv){	char r_buf[4096*2];	int  fd;	int  r_size;	int  ret_size;	r_size=atoi(argv[1]);	printf("requred real read bytes %d\n",r_size);	memset(r_buf,0,sizeof(r_buf));	fd=open(FIFO_SERVER,O_RDONLY|O_NONBLOCK,0);	//fd=open(FIFO_SERVER,O_RDONLY,0);	//在此處可以把讀程序編譯成兩個不同版本：阻塞版本及非阻塞版本	if(fd==-1)	{		printf("open %s for read error\n");		exit();		}	while(1)	{				memset(r_buf,0,sizeof(r_buf));		ret_size=read(fd,r_buf,r_size);		if(ret_size==-1)			if(errno==EAGAIN)				printf("no data avlaible\n");		printf("real read bytes %d\n",ret_size);		sleep(1);	}		pause();	unlink(FIFO_SERVER);}