It is equivalent to `f_open'(f, path, `OPEN_READONLY', `0').
The `f_open' semantics loosely follows the semantics of UNIX
The bits argument specify the open mode and is the bitwise OR of some file open bits.
At least one of the `OPEN_READONLY' and `OPEN_WRITEONLY' better be
specified. The two definitions may have funny values since they are (or may
be) redefinitions of
O_WRONLY. Due to their funny
values failing to specify one of them will have undefined results.
If the file is to be created it will be created with the permissions
permissions (in same way as the
open(2) function, the permissions
argument is passed unchanged as the third argument to the
If f is already opened `f_open' closes it before attempting open it for path operations.