views:

176

answers:

5

We're getting some odd errors reported on our website, and are trying to find out some details on who is doing the looking. I'm looking at a sample user-agent strings and seeing things like:

Mozilla/5.0 (Windows; U; Windows NT6.0; en-US; rv:1.9.0.6) Gecko/2009011913 Firefox/3.0.6

Now some of this is obvious, but some of it is less so ("U"?) From the pattern of the hits, I'd suspect that this was a robot, but I don't see anything that I recognize in this string to clue me in to that. I'd like to know what some of the things in this (and other different) strings mean. Is there a comprehensive reference somewhere?

A: 

Robots can fake User-Agent strings, so what it declares is irrelevant. It can simply be done with e.g. curl -A user-agent-here.

Robert Munteanu
Oh yes, I know that...but it seems like that because of the bad press that surrounds that kind of thing, they usually don't bother (unless they have some kind of potentially nefarious purpose).
Beska
+2  A: 

This Wikipedia page gives a good overview, and describes the meaning of the 'U' attribute as well.

Sean Bright
+1  A: 

User-agent strings (as all request headers) are not to be trusted at all, but I recommend www.useragentstring.com as a reference for helping you determine the patterns you're interested in.

annakata
Thanks. How many people know what your name means, btw? On a geek site like this I would guess a higher percentage than elsewhere, but I'd bet it's still somewhat low...
Beska
Put it this way, I'm impressed if you do...
annakata
+1  A: 

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.0.11) Gecko/2009060214 Firefox/3.0.11

This is my current user agent.
Mozilla/5.0 - browser
Macintosh - platform
U - 256 bit encryption supported
Intel Mac OS X 10.5 - my operating system
en-US - language
rv:1.9.0.11 - revision
Gecko/2009060214 - rendering engine
Firefox/3.0.11 - browser version

Hardwareguy
+1  A: 

The U stands for security as the Mozilla User Agent String Reference states. The link to wikipedia has been provided by somebody else already

In future I suggest you use these two sites

w w w.useragentstring.com/index.php

stevesouders. com/ua/parse.php