将子字符串与字符串中的特殊字符匹配

Question

I ran into a regex challenge and so far couldn't figure out the solution.

I have a string for example like this:

&str = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce malesuada sit amet risus vel ultricies. Quisque pretium leo in sem sodales, in ullamcorper dolor aliquet. Duis at massa felis. Pellentesque fringilla **'![bibendum auctor]**. Nunc scelerisque aliquam sem. Nam pharetra eros quis libero molestie iaculis. Etiam vehicula blandit ipsum in sodales. Nulla tempus cursus lacus, sed cursus ligula consequat at. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Suspendisse at blandit" ipsum, sed porta urna. Vesti&&&&bulum turpis risus, ultricies at sapien id, vehicula venenatis neque.";

And I would like to preg_match only this part: preg_match(/'![bibendum auctor]/);
As you can see, there are some special characters inside the string and this fails regexp to match the query.

I cannot use preg_quote() , as I don't want to escape the special characters at other parts of the whole string.

Answer 1

You can match anything in square brackets preceded by exclamation mark like this:

/!\[([^\]]+)\]/

working example

edit: if you want to match the exact phrase as you've tried you have to escape the brackets like thi:

/'!\[bibendum auctor\]/

example

Answer 2

You can use preg_quote on the string you are searching for like this:

$str = <<<EOT
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce malesuada sit amet risus vel ultricies. Quisque pretium leo in sem sodales, in ullamcorper dolor aliquet. Duis at massa felis. Pellentesque fringilla **'![bibendum auctor]**. Nunc scelerisque aliquam sem. Nam pharetra eros quis libero molestie iaculis. Etiam vehicula blandit ipsum in sodales. Nulla tempus cursus lacus, sed cursus ligula consequat at. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Suspendisse at blandit" ipsum, sed porta urna. Vesti&&&&bulum turpis risus, ultricies at sapien id, vehicula venenatis neque.
EOT;

$search = preg_quote('![bibendum auctor]', '/');

preg_match("/$search/", $str, $matches);
print_r($matches);

Output:

Array ( [0] => ![bibendum auctor] ) 

(In case you're wondering the <<<EOT is heredoc syntax - I just used it so I didn't have to escape all the quotes in the string)