How to detect language of text?

Question

I have a form which lets users input text snippets. So how can figure out the language of the entered text?

Specifically these languages for now:

Arabic: هذه

Answer 1

Presumably guessing the user's language is to display responses in the proper language. What about examining the browser's settings for preferred languages? Obtain that from the HTTP header Accept-Language. See section 14.4 here.