$re = '@(?(DEFINE)
(?<next_open_tag>
[^<]*+
(?i: <++[^<?s][^<]*
| <++(?! \?php
| \?=
| script\s*language\s*=\s*([\'"]?)php\g{-1}\s*>
) [^<]*
)*+
(?i: <++(?: \?php
| \?=
| [^>]+
)
| \z
)
)
)
\A (?&next_open_tag) \K
|
[^\'"`/#<?]*+
(?: \'(?:[^\'\\\\]+|\\\\.)*+\' [^\'"`/#<?]*
| "(?:[^"\\\\]+|\\\\.)*+" [^\'"`/#<?]*
| `(?:[^`\\\\]+|\\\\.)*+` [^\'"`/#<?]*
| /(?![/*]) [^\'"`/#<?]* # stop for // or /*
| # if close tag ?>
\? (?: >(?&next_open_tag)[^\'"`/#<?]* | )
| < (?: # heredoc or nowdoc
<<[\ \t]*([\'"]?)
([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)
\g{-2}[\ \t]*[\r\n]
(?-s:.*+[\r\n])*?
\g{-1}[\r\n;]
[^\'"`/#<?]*
| (?i: /script\s*>)
(?&next_open_tag)
[^\'"`/#<?]*
| [^\'"`/#<?]*
)
)*+
\K
(?: (?://|\#)(?:[^\n?]+|\?(?!>))*+ # single line comment // и #
| /\*(?:[^*]+|\*(?!/))*+\*/ # multi line comment /* */
)?
@xs';
$str = '<!-- *//* -->
<?php
$a = "text */*"; // comment
$b = \'text *//*\'; # comment
//*
if ($a) {
echo $b;
}
/*/
if ($bar) {
echo $foo;
}
// */
?>
<!-- *//* -->
<script language = "php" >
# comment ?> Text <?php $a = \'/*\'; // comment
$b = @`ls ./* -al`;
# */
</script>
<!-- *//* -->
';
$subst = "";
$result = preg_replace($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