update testFileSystem

APP_Framework/Applications/main.c

@@ -17,6 +17,31 @@
 
 extern int FrameworkInit();
 extern void ApplicationOtaTaskInit(void);
+
+void TestFileSystem (){
+    int ret = 0;
+    char w_buf[] = "hello world!";
+    char r_buf[20];
+
+    int fd_t = open("/hello.txt", O_RDWR | O_CREAT); 
+    if(fd_t >0){
+        ret = write(fd_t, w_buf, strlen(w_buf));
+        if(ret < 0){
+        printf("fd = %d write hello world failed.\n",fd_t); 
+        return NULL;
+        }
+        close(fd_t);
+
+        fd_t = open("/hello.txt", O_RDONLY);
+        ret = read(fd_t, r_buf, 20);
+        if(ret > 0)
+        printf("read len %d, r_buf %s\n",ret,r_buf); 
+        close(fd_t);
+    }
+}
+PRIV_SHELL_CMD_FUNCTION(TestFileSystem, a filesystem test sample using sd 
+    card, PRIV_SHELL_CMD_MAIN_ATTR);
+
 int main(void)
 {
 	printf("Hello, world! \n");