php – 使用fseek逐行读取一个文件

我的file.txt

#file.txt
Line 1
Line 2
Line 3
Line 4
Line 5

和代码：

<?php

$fp = fopen('file.txt','r');

$pos = -2; // Skip final new line character (Set to -1 if not present)

$lines = array();
$currentLine = '';

while (-1 !== fseek($fp,$pos,SEEK_END)) {
    $char = fgetc($fp);
    if (PHP_EOL == $char) {
            $lines[] = $currentLine;
            $currentLine = '';
    } else {
            $currentLine = $char . $currentLine;
    }
    $pos--;
}

$lines[] = $currentLine; // Grab final line

var_dump($lines);

输出：

array(5) {
   [0]=>
   string(6) "Line 5"
   [1]=>
   string(6) "Line 4"
   [2]=>
   string(6) "Line 3"
   [3]=>
   string(6) "Line 2"
   [4]=>
   string(6) "Line 1"
}

你不必象我这样追加到$lines数组,如果这是脚本的目的,你可以立即打印输出.如果要限制行数,也很容易引入一个计数器.

$linesToShow = 3;
$counter = 0;
while ($counter <= $linesToShow && -1 !== fseek($fp,SEEK_END)) {
   // Rest of code from example. After $lines[] = $currentLine; add:
   $counter++;
}