title: How to detect browser spoofing and robots from a user agent string in php
body: <p>So far I am able to detect robots from a list of user agent string by matching these strings to known user agents, but I was wondering what other methods there are to do this using php as I am retrieving fewer bots than expected using this method.</p>
  
  <p>I am also looking to find out how to detect if a browser or robot is spoofing another browser using a user agent string.</p>
  
  <p>Any advice is appreciated.</p>
  
  <p>EDIT: This has to be done using a log file with lines as follows:</p>
  
  <p>129.173.129.168 - - [11/Oct/2011:00:00:05 -0300] "GET /cams/uni_ave2.jpg?time=1318302291289 HTTP/1.1" 200 20240 "http://faculty.dentistry.dal.ca/loanertracker/webcam.html" "Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10.4; en-US; rv:1.9.2.23) Gecko/20110920 Firefox/3.6.23"</p>
  
  <p>This means I can't check user behaviour aside from access times.</p>