write file on server side Options

[DS92]

Goodmorning, I would like that input on html page are automatically saved in a txt file on server. I found that it could be reach with javascript and php scripts but I couldn't understand how.
The next step could be modify the file and read it in order to find if the client input are already in the file.
Could someone help me? thank you very much
Best Regards

[DS92]

Thank you very much, I would like that when I submit start a javascript which call a php o nodejs code to save user inputs in file txt or change txt file. I available to write server side in python php or nodejs codes. I don't know Perl code

[Christian J]

Thank you very much, I would like that when I submit start a javascript which call a php o nodejs code to save user inputs in file txt or change txt file.

You don't need javascript for that, just use the server-side script's URL in the form's ACTION attribute and the script will run automatically when the form is submitted. But if you must use javascript, it can be done with an Ajax request.

I available to write server side in python php or nodejs codes. I don't know Perl code

Wth PHP this one can be used: http://php.net/manual/en/function.file-put-contents.php