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<?php $matches = []; $str = 'foo\n```bar```'; preg_match('/(^|.*\s)```/mu', $str, $matches, PREG_OFFSET_CAPTURE, 0); var_dump($str); var_dump($matches);
Output for 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
string(14) "foo\n```bar```" array(0) { }

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