PHP supports the direct io functions as described in the Posix
Standard (Section 6) for performing I/O functions at a lower
level than the C-Language stream I/O functions (fopen, fread,..).
No external libraries are needed to build this extension.
To get these functions to work, you have to configure PHP with
This extension has no configuration directives defined in php.ini.
One resource type is defined by this extension:
a file descriptor returnded by dio_open().
This extension has no constants defined.