Sets the file position indicator for handle to the beginning of the file stream.
Siker esetén TRUE értékkel tér vissza, ellenkező esetben FALSE értéket ad.
The file pointer must be valid, and must point to a file successfully opened by fopen().
Megjegyzés: If you have opened the file in append ("a") mode, any data you write to the file will always be appended, regardless of the file position.