php man page for dio_seek

DIO_SEEK(3)								 1							       DIO_SEEK(3)

dio_seek - Seeks to pos on fd from whence

SYNOPSIS
       int dio_seek (resource  $fd, int  $pos, [int  $whence = SEEK_SET])

DESCRIPTION
	The function dio_seek(3) is used to change the file position of the given file descriptor.

PARAMETERS
	      o $fd
		- The file descriptor returned by dio_open(3).

	      o $pos
		- The new position.

	      o $whence
		- Specifies how the position $pos should be interpreted:

		     o SEEK_SET (default) - specifies that $pos is specified from the beginning of the file.

		     o SEEK_CUR - Specifies that $pos is a count of characters from the current file position. This count may be positive or nega-
		       tive.

		     o SEEK_END - Specifies that $pos is a count of characters from the end of the file. A negative  count  specifies  a  position
		       within  the current extent of the file; a positive count specifies a position past the current end. If you set the position
		       past the current end, and actually write data, you will extend the file with zeros up to that position.

RETURN VALUES
EXAMPLES
       Example #1

	      Positioning in a file

	      <?php

	      $fd = dio_open('/dev/ttyS0', O_RDWR);

	      dio_seek($fd, 10, SEEK_SET);
	      // position is now at 10 characters from the start of the file

	      dio_seek($fd, -2, SEEK_CUR);
	      // position is now at 8 characters from the start of the file

	      dio_seek($fd, -5, SEEK_END);
	      // position is now at 5 characters from the end of the file

	      dio_seek($fd, 10, SEEK_END);
	      // position is now at 10 characters past the end of the file.
	      // The 10 characters between the end of the file and the current
	      // position are filled with zeros.

	      dio_close($fd);
	      ?>

PHP Documentation Group 													       DIO_SEEK(3)