This is because we keep opening the same file, located in the same directory, adding the two strings as files, and closing again.

这是因为一直在打开同一个目录中的同一个文件，添加两个字符串作为文件，并再次关闭。

youdao

Remember from the section on opening and closing that we need two parameters (file path name and access mode to the device) to open a device on Linux.

从有关设备打开和关闭的讲解可知，我们需要两个参数(文件路径名和设备访问模式)来打开Linux设备。

youdao

It is needed for the file opening, closing, reading, and writing functions (fopen , fclose , fgets , getc , and so on), for the printf family of functions, and for the setvbuf function.

文件的打开、关闭、读和写函数(fopen 、fclose 、fgets 、getc等等)、printf函数系列和setvbuf函数都需要它。

youdao