rd.c

linux unix 入门代码上,是关于初级入门的,经典代码

#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>

struct stu_r {
	int id;
	char name[64];
	int chinese;
	int english;
	int math;
};

int
main()
{
	struct stu_r stu[10];
	int i,ret;
	int fd;

	fd=open("/tmp/score",O_RDONLY);
	if (fd==-1) {
		perror("open()");
		exit(1);
	}

	ret=read(fd,stu,sizeof(struct stu_r)*10);
	if (ret<sizeof(struct stu_r)*10) {
		fprintf(stderr,"Only %d bytes loaded.\n",ret);
	} else {
		fprintf(stderr,"Loaded.\n");
	}

	close(fd);

	for (i=0;i<ret/sizeof(struct stu_r);i++) {
		printf("Student: Name=%s(%d)\n",stu[i].name,stu[i].id);
		printf("\tmath=%d\n\n",stu[i].math);
	}

	exit(0);
}