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
whence
value. -
whence
-
whence
values are:SEEK_SET
- Set position equal tooffset
bytes.SEEK_CUR
- Set position to current location plusoffset
.SEEK_END
- Set position to end-of-file plusoffset
.
If
whence
is 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);
?>