$re = '/\$(?:(\[)|(\()|({)|(\/)).*?(?:(?=\2)(?=\3)(?=\4)\]|(?=\1)(?=\3)(?=\4)\)|(?=\1)(?=\2)(?=\4)}|(?=\1)(?=\2)(?=\3)\/)/';
$str = '// Matches
${...}
$(...)
$[...]
$/.../
// Does Not Match
${...)
${...]
${.../
$(...}
$(...]
$(.../
$[...}
$[...)
$[.../
$/...}
$/...)
$/...]';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
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