File :: open - Open file
Before opening the file, a valid file path has to be provided for the file (constructor or path()).
Implementation details
File  :: open (  )
The function opens the file referenced in path. When the file could not be opened, the function throws an exception. In order to open a non-existing file, the access mode must be set to Write or Update.
After opening a file with Read or Write access mode, last position is 0. After opening the file with Update, last position is at end of file.