I needed to make a html search box with a buttonclick that on click it will search the given sentence in .txt file(s) and show them? If yes how and is it possible to make one that works with realtime input?(changing the searched input automaticly as soon as something in input changes) thanks.
You're looking to make a web app? Your question is undefined.
You can't do such a thing using HTML (HyperText Markup Language), it's not a programming language. The thing you do in HTML is form a
box/text field in which you type.
And by the way, you already have such a function in all browsers, click
"CTRL+F" on any page, and type something, it works realtime using the input.