Developer wanted to write a piece code

I have found that if adding question mark ? after the domain name and then add any letters, it will be direct to home page instead of error page. for example, [login to view URL] if you click the link it will turn to error page, but if you add the question mark between forward slash / and adffg then you go to the home page instead of error page I want someone to write a piece of code to prevent this happening. the code will be insert into my homepage you can use php, javascript or something else to write the code. the successful sample as below: when you click the link below, you visit an error page instead of direct to home page of the website [login to view URL] if you have any other solution for the problem, please leave me a message