Php/docs/function.dio-seek
dio_seek
(PHP 4 >= 4.2.0, PHP 5 < 5.1.0)
dio_seek — Seeks to pos on fd from whence
Description
dio_seek
( resource $fd
, int $pos
[, int $whence
= SEEK_SET
] ) : int
The function dio_seek() is used to change the file position of the given file descriptor.
Parameters
fd
- The file descriptor returned by dio_open().
pos
- The new position.
whence
- Specifies how the position
pos
should be interpreted:
SEEK_SET
(default) - specifies thatpos
is specified from the beginning of the file.SEEK_CUR
- Specifies thatpos
is a count of characters from the current file position. This count may be positive or negative.SEEK_END
- Specifies thatpos
is a count of characters from the end of the file. A negative count specifies a position within the current extent of the file; a positive count specifies a position past the current end. If you set the position past the current end, and actually write data, you will extend the file with zeros up to that position.
Return Values
Examples
Example #1 Positioning in a file
<?php$fd = dio_open('/dev/ttyS0', O_RDWR);dio_seek($fd, 10, SEEK_SET);// position is now at 10 characters from the start of the filedio_seek($fd, -2, SEEK_CUR);// position is now at 8 characters from the start of the filedio_seek($fd, -5, SEEK_END);// position is now at 5 characters from the end of the filedio_seek($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);?>