open file and remove first tag - php

Question

This would be a HTML file:
<li class="msgln">hello</li><li class="msgln">hi</li><li class="msgln">hey</li>
And php script:
$fp = fopen("file.html", 'a');
....
fclose($fp);
How to remove first <li class="msgln">hello</li>?
Content in <li> is dynamically changed

Answer 1

This will work even if the first li would contain other nested lis:
<?php
$doc = new DOMDocument();
$doc->loadHTML('<li class="msgln">hello</li><li class="msgln">hi</li><li class="msgln">hey</li>
');
$root = $doc->documentElement;
$p = $doc->documentElement->childNodes->item(0)->childNodes;
$li = $doc->getElementsByTagName('li')->item(0);
$li->parentNode->removeChild($li);
$html = '';
foreach ($root->childNodes->item(0)->childNodes as $child) {
$html .= $doc->saveXML($child);
}
echo $html;
?>
using regex may cause unexpected results.

Answer 2

You can use preg_replace to achieve this:
$html = file_get_contents('file.html');
$html = preg_replace('#^<li[^>]*>[^<]+</li>#i', '', $html);

Answer 3

If the content of the file is exactly as described then you could use strip_tags() such like:
$fp = fopen("file.html", 'a');
$content = fread($fp);
$content = strip_tags($content);
fclose($fp);
Alternatively you could use regular expressions but this would be slower.

Answer 4

$fp = fopen("file.html", 'a');
$content = fread($fp);
$text = preg_replace( "/<li.+?>.+?<\/li>/is", "", $content, 1 );
fclose($fp);

Answer 5

try this (without regex)
//string contains the file value
$string = '<li class="msgln">hello</li><li class="msgln">hi</li><li class="msgln">hey</li>';
$tag = '</li>';
$lis = explode($tag, $string);
if(count($lis) > 0) {
unset($lis[0]);
$string = implode($tag, $lis);
}