RT-Thread-【7天入门RTOS网络编程】Wendell Day1-2 文件系统相关作业☆☆RT-Thread问答社区

【7天入门RTOS网络编程】Wendell Day1-2 文件系统相关作业☆☆

发布于 2018-10-20 22:44:59 浏览：1809 订阅该版

* 本帖最后由 san兄弟 于 2018-10-24 12:55 编辑 *

学习了【7天入门RTOS网络编程】的课程，感觉课程讲解很详细，包括常见的问题及解决方法都整理的很详细，学习了第一至三节，实用Env工具配置的方法组织项目文件实在是太方便了，解决了常规的自己手动构建文件工程的繁琐，点赞！现在将DAY1-2的作业提交在此，虽然有些晚了，但是确实经过了仔细的思考。
作业1：获取并运行文件系统相关示例程序。前三节都按照教程一步步学习了，其中也遇到了一些问题，都按照群文件给出的方法一一解决了，将学习过程中的部分截图贴出来吧。![1.jpg](/uploads/201810/20/223000c066156h6q5w1n5n.jpg)
![2.jpg](/uploads/201810/20/223001grepjg4jzeweewrg.jpg)
![3.jpg](/uploads/201810/20/223001dz887n8enype0w11.jpg)
![4.jpg](/uploads/201810/20/223001dgk2su63klhuuxt8.jpg)
![5.jpg](/uploads/201810/20/223001yvez1m696fzmcp65.jpg)
作业2：文本数据替换，1.txt 里面有文本信息 123456789，将 123 替换为 abc。```#include <rtthread.h>
#include <dfs_posix.h> /* 当需要使用文件操作时，需要包含这个头文件 */

static void replace_sample(void) /*homework day1-2,question 2*/
{
 int ret,seek_flag=0;
 int fd, size;
 DIR *dirp;
 char *p_str;
 struct dirent *dp;
 char s[] = "123456789 ", buffer[80];

rt_kprintf("homework day1-2,question 2 ");
 /* 创建目录*/
 ret = mkdir("/homework1_2", 0x777);
 if (ret < 0)
 {
 /* 创建目录失败*/
 rt_kprintf("dir /homework1_2 error! ");
 }
 else
 {
 /* 创建目录成功*/
 rt_kprintf("mkdir /homework1_2 ok! ");
 }

/* 打开/homework1_2 目录*/
 dirp = opendir("/homework1_2");
 if (dirp == RT_NULL)
 {
 rt_kprintf("open directory /homework1_2 error! ");
 }
 else
 {
 rt_kprintf("open directory /homework1_2 OK! ");
 /* 读取目录*/
 while ((dp = readdir(dirp)) != RT_NULL)
 {
 rt_kprintf("found %s ", dp->d_name);
 if(strcmp(dp->d_name, "1.txt") == 0)
 {
 seek_flag =1;
 break;
 }
 }
 if(seek_flag==0)
 { 
 rt_kprintf("current directory do not have 1.txt ");
 fd = open("/homework1_2/1.txt", O_WRONLY | O_CREAT);
 if (fd >= 0)
 {
 rt_kprintf("fd = %d ", fd);
 rt_kprintf("creat 1.txt OK ");
 write(fd, s, sizeof(s)); 
 }
 else 
 {
 rt_kprintf("creat 1.txt error ");
 }
 close(fd);
 }
 
 fd = open("/homework1_2/1.txt", O_RDWR);
 if (fd >= 0)
 {
 size = read(fd, buffer, sizeof(buffer));
 if(size >= 0)
 {
 rt_kprintf("read file 1.txt : %s ", buffer);
 p_str = strstr(buffer, "123");
 if (NULL == p_str)
 {
 rt_kprintf("do not find string 123. ");
 }
 else
 {
 rt_kprintf("replace 123 with abc. ");
 strncpy(p_str, "abc", 3);
 rt_kprintf("changed buffer : %s ", buffer);
 /*当前文件偏移量归零*/
 lseek(fd,0,SEEK_SET);
 /*写入长度size与读取长度相同，直接写入sizeof（buffer）后面会带有乱码*/
 write(fd, buffer, size);
 }
 }
 else 
 {
 rt_kprintf("read 1.txt error ");
 } 
 }
 close(fd);
 /*检查是否替换成功*/
 rt_kprintf("check file 1.txt ");
 fd = open("/homework1_2/1.txt", O_RDONLY);
 if (fd >= 0)
 {
 size = read(fd, buffer, sizeof(buffer));
 rt_kprintf("read file 1.txt : %s ", buffer);
 }
 else 
 {
 rt_kprintf("check 1.txt error ");
 }
 close(fd);
 }
 /* 关闭目录 */
 closedir(dirp);
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(replace_sample, replace sample);```

运行结果：         第一次运行结果截图：生成1.txt，写入内容，并替换指定字符串。![6.jpg](/uploads/201810/20/223817aqz4b68u46gglze2.jpg)
       第二次运行结果截图：打开1.txt，报错，找不到指定字符串，因为第一次执行已经替换。![7.jpg](/uploads/201810/20/223817hih17gslzoss7lo0.jpg)
执行之后，打开sd.bin中的homework1_2/1.txt，显示如下：![8.jpg](/uploads/201810/20/224055i1jznpwzqqk11nls.jpg)

作业3：文件匹配: 有一系列文件如：1.txt, 12.txt, 123.txt,从中找出1.txt,并将文件内容输出出来。其实作业2中已经包含了作业3的内容，作业3代码如下：```static void find_txt_sample(void) /*homework day1-2,question 2*/
{
 int seek_flag=0;
 DIR *dirp;
 struct dirent *dp;
 int fd, size;
 char buffer[80];
 rt_kprintf("homework day1-2,question 3 ");
 /* 打开/homework1_2 目录*/
 dirp = opendir("/homework1_2");
 if (dirp == RT_NULL)
 {
 rt_kprintf("open directory /homework1_2 error! ");
 }
 else
 {
 rt_kprintf("open directory /homework1_2 OK! ");
 /* 读取目录*/
 while ((dp = readdir(dirp)) != RT_NULL)
 {
 rt_kprintf("found %s ", dp->d_name);
 if(strcmp(dp->d_name, "1.txt") == 0)
 {
 seek_flag =1;
 break;
 }
 }
 if(seek_flag==0)
 { 
 rt_kprintf("current directory do not have 1.txt ");
 fd = open("/homework1_2/1.txt", O_WRONLY | O_CREAT);
 if (fd >= 0)
 {
 rt_kprintf("creat 1.txt OK "); 
 }
 else 
 {
 rt_kprintf("creat 1.txt error ");
 }
 close(fd);
 }
 else 
 {
 fd = open("/homework1_2/1.txt", O_RDWR);
 if (fd >= 0)
 {
 size = read(fd, buffer, sizeof(buffer));
 if(size >= 0)
 {
 rt_kprintf("read file 1.txt : %s ", buffer);
 }
 }
 else 
 {
 rt_kprintf("read 1.txt error ");
 } 
 close(fd);
 }
 }
 /* 关闭目录 */
 closedir(dirp);
}
/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(find_txt_sample, find txt sample);```运行结果：![10.jpg](/uploads/201810/20/224353eut1eshs75vinmst.jpg)
程序源码：![homework1_2.c](/uploads/201810/20/224444yubyznere3v3v1kz.attach)