Question

Per the following documentation: https://developers.google.com/chrome/mobile/docs/user-agent

Here is Chrome for iOS UA String:

Mozilla/5.0 (iPhone; U; CPU iPhone OS 5_1_1 like Mac OS X; en) AppleWebKit/534.46.0 (KHTML, like Gecko) CriOS/19.0.1084.60 Mobile/9B206 Safari/7534.48.3

And here is Safari for iOS UA String:

Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543 Safari/419.3

As best as I can tell the difference going forward will be that Chrome includes “CriOS”. I want to be able to distinguish between these two browsers and so set about doing that using a regular expression.

Using:

/Gecko\) (?!CriOS)/

I’m able to do that but am paranoid as I am not including iPhone in the expression (perhaps this will also trigger on Android, etc.)

I want to write the following regular expression that returns a match when:

1. The string contains “iPhone”
2. The string does not contain “CriOS”

How would I go about doing that?

FYI I’ve been using rubular for testing reg exp which has been awesome http://rubular.com/

Answer 1

This should do it :

iPhone(?!.*?CriOS)

iPhone matches any occurence of that word. It then uses a negative lookahead from the iPhone match. .*?CriOS matches any/all characters until it finds CriOS. The (?!expr) is a negative lookahead. If the expression is false then what comes before it (Iphone) will match, otherwise it won’t.