XXIII. Direct IO Functions


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(),..). The use of the DIO functions should be considered only when direct control of a device is needed. In all other cases, the standard filesystem functions are more than adequate.

Note: This extension is not available on Windows platforms.


No external libraries are needed to build this extension.


To get these functions to work, you have to configure PHP with --enable-dio.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

One resource type is defined by this extension: a file descriptor returned by dio_open().

Predefined Constants

This extension has no constants defined.

Table of Contents
dio_close -- Closes the file descriptor given by fd
dio_fcntl -- Performs a c library fcntl on fd
dio_open --  Opens a new filename with specified permissions of flags and creation permissions of mode
dio_read --  Reads n bytes from fd and returns them, if n is not specified, reads 1k block
dio_seek -- Seeks to pos on fd from whence
dio_stat --  Gets stat information about the file descriptor fd
dio_tcsetattr --  Sets terminal attributes and baud rate for a serial port
dio_truncate --  Truncates file descriptor fd to offset bytes
dio_write --  Writes data to fd with optional truncation at length