dio_open Opens a new filename with specified permissions of flags and creation permissions of mode resourcedio_open stringfilename intflags intmode dio_open opens a file and returns a new file descriptor for it, or -1 if any error occurred. If flags is O_CREAT, optional third parameter mode will set the mode of the file (creation permissions). The flags parameter can be one of the following options: O_RDONLY - opens the file for read access O_WRONLY - opens the file for write access O_RDWR - opens the file for both reading and writing The flags parameter can also include any combination of the following flags: O_CREAT - creates the file, if it doesn't already exist O_EXCL - if both, O_CREAT and O_EXCL are set, dio_open fails, if file already exists O_TRUNC - if file exists, and its opened for write access, file will be truncated to zero length. O_APPEND - write operations write data at the end of file O_NONBLOCK - sets non blocking mode