[c-nsp] cisco regex puzzle of the day

[Mack McBride]

Yes agreed.

Mack McBride | Network Architect | ViaWest, Inc.
O: 720.891.2502 | mack.mcbride at viawest.com | www.viawest.com | LinkedIn | Twitter | YouTube


-----Original Message-----
From: cisco-nsp [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Saku Ytti
Sent: Thursday, March 12, 2015 3:50 AM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] cisco regex puzzle of the day

On (2015-03-12 01:12 +0000), Mack McBride wrote:

Hey,

> The junos expression in question DOES NOT involve backtracking.
> After a match there is no need to backtrack.
>
> The expression in question goes character by character excluding the 64500.
> Note the last part matches 6 digit ASNs that start with 64500.

I think we miscommunicated. Originally I explained IOS does not work, because it does backtracking, not talking about JunOS at all.
Then you mentioned that particular JunOS example does not do backtracking, which I understood you claiming JunOS does not support backtracking at all

So to summarize, both IOS and JunOS do backtracking, and it cannot be turned off. But indeed, ^64500+ [^64500] does not require backtracking, 64500+ never needs to be unconsumed to satisfy the [^64500]

--
  ++ytti
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/
This message contains information that may be confidential, privileged or otherwise protected by law from disclosure. It is intended for the exclusive use of the addressee(s). Unless you are the addressee or authorized agent of the addressee, you may not review, copy, distribute or disclose to anyone the message or any information contained within. If you have received this message in error, please contact the sender by electronic reply and immediately delete all copies of the message.