php教程

SplFileObject::seek

(PHP 5 >= 5.1.0, PHP 7)

SplFileObject::seekSeek to specified line

说明

public SplFileObject::seek ( int $line_pos ) : void

Seek to specified line in the file.

参数

line_pos

The zero-based line number to seek to.

返回值

没有返回值。

错误/异常

Throws a LogicException if the line_pos is negative.

范例

Example #1 SplFileObject::seek() example

This example outputs the third line of the script which is found at position 2.

<?php
$file 
= new SplFileObject(__FILE__);
$file->seek(2);
echo 
$file->current();
?>

以上例程的输出类似于:

$file->seek(2);

参见

User Contributed Notes

ahmad_maqsood at waku-2 dot com 21-Sep-2017 09:19
A sleek way of counting the number of lines in a file can be like below

$file = new \SplFileObject('file.extension', 'r');
$file->seek(PHP_INT_MAX);

echo $file->key() + 1;

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