SplFileObject::seek()
(PHP 5 >= 5.1.0, PHP 7)
Seek 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_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;