(PHP 4 >= 4.2.0)
dio_open -- Opens a new filename with specified permissions of flags and creation permissions of modedio_open() opens a file and returns a new file descriptor for it, or FALSE if any error occurred. If flags is O_CREAT, the 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.
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 the file already exists.
O_TRUNC - if the file exists, and its opened for write access, the file will be truncated to zero length.
O_APPEND - write operations write data at the end of the file.
O_NONBLOCK - sets non blocking mode.