SplFileObject::seek()

(PHP 5 >= 5.1.0, PHP 7)

Seek to specified line

说明

publicSplFileObject::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_posis negative.

范例

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

• SplFileObject::current() Retrieve current line of file
• SplFileObject::key() Get line number
• SplFileObject::next() Read next line
• SplFileObject::rewind() Rewind the file to the first line
• SplFileObject::valid() Not at EOF

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;