Direct IO
PHP Manual


(PHP 4 >= 4.2.0, PHP 5 <= 5.0.5)

dio_open — Opens a new filename with specified permissions of flags and creation permissions of mode


resource dio_open ( string $filename , int $flags [, int $mode ] )

dio_open() opens a file and returns a new file descriptor for it.



The opened file.


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 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.


If flags is O_CREAT, mode will set the mode of the file (creation permissions).

  • 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.

Return Values

A file descriptor or FALSE on error.


Example#1 Opening a file descriptor


dio_open('/dev/ttyS0'O_RDWR O_NOCTTY O_NONBLOCK);


See Also

Direct IO
PHP Manual