Try to understand Exceptions Regex Urls

Question

I don't understand this. Doesn't the first Regex cover all the others? Sophos provides this default rule for Sharepoint: 
 
 Matching URLs: 
 ^([a-zA-Z0-9.-]*\.)?sharepointonline\.com\/ 
 ^cdn\.sharepointonline\.com\/ 
 ^privatecdn\.sharepointonline\.com\/ 
 ^publiccdn\.sharepointonline\.com\/ 
 ^static\.sharepointonline\.com\/ 
 
 Doesn't ^([a-zA-Z0-9.-]*\.)?sharepointonline\.com\/ basically amount to *.sharepointonline.com/*. Why are the other 4 needed? 
 
 Jason

QC · Accepted Answer

Hello JasonIstre , 
 as H_Patel said, The first entry [...] should be enough to match all others . This is the answer to your first question Doesn't the first Regex cover all the others? As for Why are the other 4 needed? - perhaps no one can really tell. Back in the 1980s we had access to parts of IBM's source code. Occasionally you stumbled over snippets of dead code (i.e. instructions that could never be reached) or redundant logic. If you asked a technician why is this there? an old hand's stock response was Just to confuse the Russians . [;)] 
 Christian

FormerMember · Answer

Hi, 
 Thank you for providing KBA link. If you search sharepointonline, there is only one entry in the KBA. However, the all.tar and required.tar files contains all the domains for sharepointonline and the listed domains are required by the Microsoft. If your only concern is about the exception (([a-zA-Z0-9.-]*\.)?sharepoint\.com\/) covers all others or not. The answer is yes it covers all other domains that you mentioned in the post. 
 Thanks,