$re = '/(\x{2019})\x{2019}(.+?)\x{2018}(\x{2018})/s';
$str = '
I have a document which contains lots of sentences in quotes. Issue is that some of them are properly quoted and some of them have reverse quotes, meaning the opening quotes are at the end of the sentence and closing quotes in the beginning. Like so:
’’المعلقات السبعہ‘‘
‘‘المعلقات السبعہ’’
';
$subst = "$3$3$2$1$1";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php