How to detect the language of a given text

In my Rails 3 application, users may write messages in 开发者_开发知识库forum. I would like to identify what the language is for a given message. I'm interested in English, Russian, and Hebrew languages. Is there any built-in library in Ruby/Rails for such a task? If not, any ideas will be appreciated.

Use this: https://github.com/nashby/wtf_lang

"ruby is so awesome!".lang # => "en"
"ruby is so awesome!".full_lang # => "ENGLISH"

You can use the api provided by google to guess it with google translate.

See here for documentation : http://code.google.com/apis/language/translate/v1/using_rest_langdetect.html

Since you're concerned with languages with different character sets you could dig up the character codes that are predominantly in your strings. You could then see if they fall into the code sets that represent hebrew / cryllic characters.

Perhaps you could look at the whatlanguage gem?

Take a look at this blog
http://blog.kenweiner.com/2008/04/server-side-language-detection-with.html
This may be helpful

Language Detection API provides Ruby GEM to detect language.

Just a quick demo of WhatLanguage for anyone interested : http://www.youtube.com/watch?v=lNqZ2cqOReo&list=UUJ_3fstMOH-g4yBxtvgAWkw&index=0&feature=plcp

http://rubygems.org/gems/prose Prose dose it without a gem. Try it.