Saturday, June 2, 2007

Testing Google- Boundary Values Explored

Another interesting feature which i tested was Boundary value of Google's search box. I was reading this interesting post by Debasis and i found out the work done by him really impressive and thought of doing my own boundary value exploration for Google's search box...


Debasis has mentioned in his analysis that he found out the maximum no of characters which can be pasted in the box is 2048 and on further analysis he found that it is 1980 characters which when passed will result directly on a "Google 404 Bad request Page".


Here is what i have found:


I found that it is not the exact no 1980 which can cause the "Google 404 Bad request" page. I found it to be something else. I found that it is not the no. of characters which really matter for getting the bad request page, however it is the positioning and placements of few special characters like #,@, ( to name a few which were causing bad request page.

We need to definitely explore a bit in deep to find out what exactly causes bad request page because after my initial investigations i am now sure that it is something which needs time and deep investigation to be done to find out the exact reason.


I found out that i was able to reproduce the "Google 404 Bad request" page several times using different combinations and different placements of characters in the search string. The interesting part was that whenever i included a ( after several @ symbols in my search string, the result would automatically shift the line starting with ( on the next line. For more clarity check out the snapshot here.


I was surprised that why the search was displaying (, # and few other characters in next line of search results. I found out that increasing the no. of #'s in the search string was increasing the chances of minimising the 1980 barrier required to get a Bad request page. I pasted the string mentioned below which has 770 characters in it..


_________####_______________#############____________________+++++++++++++++++++++++++++++++++++@@@@@@@@######@@@+++++@@@@@@@@@@@@@@@@@(((((((((((((((((((++++++++))))))))))((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((@@@@@@@@@@@@@@@@@((((((((((((((((((((((((@@@@@@@@@@@@@@@@@@@@@@@))))))))))))))))))))))##################################################################********************************(((((((((((((((((((((((((((((((^^^^^^^^^^^^^^^^^^^^^^^((((((((((((((((((((((((((((((((((((((((=====================================================================================================================================((((((((((((((((((((()))))))))))))))))))))))))))))))))))))))))))))))0#################################################(######


Paste the above string exactly in the Google search box and you will find that when we press Search Button we get the bad request error. Now if i reduce the above string to 769 characters i was not getting bad request error.

The interesting part was that sometimes this bad request error comes also when i have 765 characters and sometimes it does not comes.


Strange but true.. I see definitely here a relation between how we place characters and which characters are at what position has definitely to do something with bad request page.


I am sure that we can even further reduce the no of characters to get bad request page.


Output:


We need to explore more on what exactly causes Bad Request Page..


Happy Googling..
Madhukar.











2 comments:

sachin said...

Interesting post, before posting this comment i tested google a found the same.

Anonymous said...

the same thing you can check with the SMS service in the mobile. Normally a single text message can have 160 letters. Now when you try inserting #,@ etc. special characters, the length of the single SMS is shrinked form the 160 characters limit.
If you want to dig more, check how the special caracters are stored, its ASCII value, the number of bits which is required to stored it...

Regards, Suhas M.