作业

使用write和read完成文件的拷贝。

将1.txt文件内容拷贝到2.txt中

#include <myhead.h>
int main(int argc, const char *argv[])
{
	if(argc != 3)
	{
		printf("外部传参错误\n");
		return -1;
	}
	int fd1;
	fd1 = open(argv[1],O_RDONLY);
	if(fd1 == -1)
	{
		perror("open");
		return -1;
	}
	int fd2;
	fd2 = open(argv[2],O_WRONLY | O_CREAT | O_TRUNC,0664);
	if(fd2 == -1)
	{
		perror("open");
		return -1;
	}

	char buff[5];
    while((read(fd1,buff,sizeof(buff)))!=0)
    {
        write(fd2,buff,sizeof(buff));
    }
	printf("拷贝成功\n");

	close(fd1);
	close(fd2);
	return 0;
}

运行结果：

知识梳理