Question: I have project based on linux based embedded application. Here i have an ELF file which i want to ensure that OpenGrok Indexing using only the symbols that are part of the ELF file excluding all non relevant/ non compiled portion of the project files. Is this possible with OpenGrok indexing ? If so what is the command to generate this index. Currently i used below command to generate the index for the entire source ..
java   

-Djava.util.logging.config.file=/opengrok/etc/logging.properties   

-jar /opengrok/dist/lib/opengrok.jar   

-c /usr/local/bin/ctags   

-s /opengrok/src -d /opengrok/data -H -P -S -G   

-W /opengrok/etc/configuration.xml -U http://localhost:8080/source

Answer: 
Because change the URL will not trigger re-render the app. So you need to listen to the URL change events to update your components. I don't know which event to listen to for the pathname. But for the hash, you can try `hashchange`.

Example for Hash:

```
export default function App() {
  const [hash, setHash] = React.useState(window.location.hash);
  React.useEffect(() => {
    const handler = () => {
      setHash((prev) => {
        const newHash = window.location.hash;
        if (prev !== newHash) {
          return newHash;
        }
        return prev;
      });
    };
    window.addEventListener("hashchange", handler);
    return () => {
      window.removeEventListener("hashchange", handler);
    };
  }, []);
  return (
    <div className="App">
      <nav>
        <ul>
          <li>
            <a href="#hash1">hash 1</a>
          </li>
          <li>
            <a href="#hash2">hash 2</a>
          </li>
        </ul>
      </nav>
      <div>Current hash: {hash}</div>
    </div>
  );
}

```
use `Switch` and `Route`: <https://reactrouter.com/web/api/Switch>, you don't have to use your own switch case ;)