$re = '/^("([^"]|\\\\")*?")$|^(\'([^\']|\\\\\')*?\')$|^(`([^`]|\\\\`)*?`)$/m';
$str = '// Should pass
"doubleQuotes"
\'singleQuote\'
"thisis\'single\'insideDouble"
\'thisis"double"insidesSingle\'
`this is sometext inside back quote`
"sample\\"app\\""
// Should fail
"thisis"double"insidesDouble"
\'thisis\'single\'insidesSingle\'
`this is sometext `inside` back quote`';
preg_match_all($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