C language fopen parameters (r +, w +, a +), fopen

C language fopen parameters (r +, w +, a +), fopen

After searching for some materials and experimenting in person, we can conclude that:

R +: When an existing file is opened, the cursor is at the beginning. The file is readable and writable,

When writing data, because the cursor is at the beginning, the original data will be overwritten.

W +: When the opened file already exists, it overwrites the original file.

A +: When an existing file is opened, the cursor is at the end of the file. The file is readable and writable.

When reading data, the cursor will return to the beginning