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<?php function tagify($str, $baseUrl = '/board/') { $baseUrl = rtrim($baseUrl, '/'); return preg_replace('/ (?!<a[^<>]*>[^\#]*) # Dont match if there is an opening <a> tag and any chars after it. \#([-_\w]+\b) # Match the hashtag. (?![^<]*<\/a>) # Ignore any anding </a> tag including any chars before it not in hashtag. /ix', '<a href="'.$baseUrl.'/$1">#$1</a>', $str); } $str = <<<STR This is <a href="http://foo.com">This is #foo</a>. Simple #html-stuff text <a href="http://foobar.com#baz">#simple</a> <span class="simple">simple #simple text text</span> STR; echo tagify($str);
Output for 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Warning: preg_replace(): Unknown modifier 'a' in /in/ef8Gd on line 6
Output for 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.38, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28
Warning: preg_replace(): Unknown modifier 'a' in /in/ef8Gd on line 10
Output for 4.3.0 - 4.3.10
Warning: Unknown modifier 'a' in /in/ef8Gd on line 10

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