SplFileObject::fseek
(PHP 5 >= 5.1.0, PHP 7)
SplFileObject::fseek — Seek to a position
说明
public SplFileObject::fseek
( int
$offset
[, int $whence = SEEK_SET
] ) : int
Seek to a position in the file measured in bytes
from the beginning of the file, obtained by adding
offset to the position specified by
whence.
参数
-
offset -
The offset. A negative value can be used to move backwards through the file which is useful when SEEK_END is used as the
whencevalue. -
whence -
whencevalues are:SEEK_SET- Set position equal tooffsetbytes.SEEK_CUR- Set position to current location plusoffset.SEEK_END- Set position to end-of-file plusoffset.
If
whenceis not specified, it is assumed to beSEEK_SET.
返回值
Returns 0 if the seek was successful, -1 otherwise. Note that seeking past EOF is not considered an error.
范例
Example #1 SplFileObject::fseek() example
<?php
$file = new SplFileObject("somefile.txt");
// Read first line
$data = $file->fgets();
// Move back to the beginning of the file
// Same as $file->rewind();
$file->fseek(0);
?>