opens a file
On success a valid file handle is returned, on failure an appropriate error-object is returned.
Possible flag combinations:
r: Open a file for reading only.
r+: Open a file for reading and writing.
w: Create a new or truncate an existing file and open it for writing only.
w+: Create a new or truncate an existing file and open it for reading and writing.
a: Create a new or open an existing file. The current file position is initially at the end of the file. The file is opened for writing only.
a+: Create a new or open an existing file. The current file position is initially at the end of the file. The file is opened for reading and writing.
The optional mode parameter is a string of the form "rwxrwxrwx". The default value is "rw-r--r--".
This function needs I/O-access rights.
| std::close | closes the specified file without returning success status |
| std::read | a low level read function |
| std::write | a low level write function |
| std::fsync | flushes all buffers associated with the file descriptor |