Is there a way to recognize google bots with the php?

Is there a way to recognize google bots with the php?

References

Reference NO 1

http://stackoverflow.com/questions/15187448/is-there-a-way-to-recognize-google-bots-with-the-php

Reference NO 2

http://stackoverflow.com/questions/916147/how-to-identify-web-crawlers-of-google-yahoo-msn-by-php

Reference NO 3

http://productforums.google.com/d/topic/webmasters/S8pTm-kjvi0

Reference NO 4

http://webmasters.stackexchange.com/questions/11669/what-is-the-best-way-to-exclude-bots-from-view-counts

Reference NO 5

http://www.cult-f.net/detect-crawlers-with-php/

Reference NO 6

http://howik.com/Identify_and_block_fake/bad_bots_in_php_including_fake_google/bing/yahoo_bots

Reference NO 7

https://forums.digitalpoint.com/threads/how-do-i-find-if-google-bot-is-visiting-my-site.1069063/

Reference NO 8

http://www.blastam.com/blog/index.php/2012/06/block-web-monitoring-bots-in-google-analytics/