Roughly matching an ipv6 address with sql wildcard

neilwatson has asked for the wisdom of the Perl Monks concerning the following question:

Grettings. Why does this test fail?

#!/usr/bin/perl

use strict;
use warnings;
use Test::More;
use Regexp::Common qw/ net /;

my $ip_query = "2 001:470:1d:a2f::%"; 

my $regex = qr/\A 
   (?: $RE{net}{IPv6} ) | # A full IPv6 address
   (?: [0-9a-f:%]+    )   # A portion of an IPv6 address with SQL % wi
+ldcards
\Z/imsx;

unlike( $ip_query, $regex, "Test [$ip_query] against big regex" );

done_testing();
[download]

Neil Watson
watson-wilson.ca

Comment on Roughly matching an ipv6 address with sql wildcard Download Code

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Re: Roughly matching an ipv6 address with sql wildcard by graff (Chancellor) on Sep 10, 2015 at 01:18 UTC
I'm not sure I understand the question. Are you asking: "Because there is a space in the value of $ip_query, it should not match $regex, but the test shows that it does match. Why is that?" If so, it's interesting that if I take `(?: $RE{net}{IPv6} ) \|` out of the code, it behaves as expected -- that is, the value of $ip_query does not match $regex, when $regex is just `(?: [0-9a-f:%]+)` Also interesting: when $regex is just `(?: $RE{net}{IPv6} )` the string does not match, as expected -- that is, the test passes. Looks like you need a set of parens that surrounds the ~~conjunction~~ alternation: `my $regex = qr/\A ( (?: $RE{net}{IPv6} ) \| # A full IPv6 address (?: [0-9a-f:%]+ ) # A portion of an IPv6 address with SQL % wi +ldcards ) \Z/imsx;` [download]	[reply] [d/l] [select]
Re^2: Roughly matching an ipv6 address with sql wildcard by neilwatson (Priest) on Sep 10, 2015 at 01:55 UTC
You are right on all counts. I do not know why the extra brackets are needed. I must sleep on it. Neil Watson watson-wilson.ca	[reply]
Re^3: Roughly matching an ipv6 address with sql wildcard by graff (Chancellor) on Sep 10, 2015 at 02:03 UTC
The extra parens are needed in order for the anchors to do what you want. The OP regex was really saying: "if the string STARTS with an IPv6 string, OR if it ENDS with something that contains one or more IP address characters and/or percent signs". BTW, you might want to include underscore as a possible sql wildcard character, because it is (and can be very useful in certain cases).	[reply]
Re^4: Roughly matching an ipv6 address with sql wildcard by neilwatson (Priest) on Sep 10, 2015 at 12:16 UTC
Re^5: Roughly matching an ipv6 address with sql wildcard by graff (Chancellor) on Sep 10, 2015 at 14:12 UTC
Re^3: Roughly matching an ipv6 address with sql wildcard by Anonymous Monk on Sep 10, 2015 at 02:12 UTC
You are right on all counts. I do not know why the extra brackets are needed. I must sleep on it. :) qr{\A ipv6 \| alt \Z}imxs Its either begin string with ipv6 or end string with alt other regex tools, ppixregexplain.pl ... Read more... (2 kB) rxrx Read more... (650 Bytes)	[reply] [d/l] [select]


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