[squid-users] correct regular expression to use to capture all

[Alex Rousskov]

On 7/8/23 17:49, robert k Wild wrote:
> So will this
> 
> (^|\.)redshift3d\.com$
> 
> I know it will match
> 
> Blah.redshift3d.com and redshift3d.com
> 
> But what about
> 
> Blah.Blah.redshift3d.com

It will also match, for the same set of reasons.

FWIW, I am worried that you keep asking about specific basic matching 
examples. If necessary, you can test such matches online[1] or using 
something like "grep -E" (not to mention Squid itself). The answers here 
will vary in quality and will usually not cover what you really want to 
know -- what input the regular expression will (not) match besides your 
specific examples. Have you tried reading regular expression tutorials 
and using tools[1] that explain the meaning of specific regular 
expressions? There ought to be a better way to learn how regular 
expressions work!

[1] For example: regexr.com/7gms6


Cheers,

Alex.


> On Sat, 8 Jul 2023, 22:32 Alex Rousskov wrote:
> 
>     On 7/8/23 06:14, Stuart Henderson wrote:
>      > On 2023-07-07, robert k Wild <robertkwild at gmail.com
>     <mailto:robertkwild at gmail.com>> wrote:
>      >> --===============6398075081121841451==
>      >> Content-Type: multipart/alternative;
>     boundary="000000000000a03dcc05ffeb4428"
>      >>
>      >> --000000000000a03dcc05ffeb4428
>      >> Content-Type: text/plain; charset="UTF-8"
>      >>
>      >> hi all,
>      >>
>      >> i know ive been talking about this before but i want to
>     understand why i
>      >> cant use this regex
>      >>
>      >> (^|.*)redshift3d.com <http://redshift3d.com>$
>      >
>      > this matches anythingredshift3d[any single character or nothing]com
> 
>     Correction: A regular expression "." does _not_ match "nothing" (i.e.
>     zero characters).
> 
>     In some contexts, "." may not even match some special single
>     characters,
>     but those contexts are probably not applicable to this thread scope.
> 
> 
>      >> instead i have to use this
>      >>
>      >> (^|\.)redshift3d.com <http://redshift3d.com>$ OR
>      >
>      > this matches redshift3d[any single character or nothing]com
>      > or anything.redshift3d[any single character or nothing]com
> 
>     ... or .redshift3d.com <http://redshift3d.com>
> 
>     Same "nothing" correction here.
> 
> 
>      >> (^|\.)redshift3d\.com$
>      >
>      > this only matches redshift3d.com <http://redshift3d.com> or
>     anything.redshift3d.com <http://anything.redshift3d.com>
> 
>     ... or .redshift3d.com <http://redshift3d.com>
> 
> 
>     Alex.
> 
> 
>      > So, if you only want to match on things exactly in the
>     redshift3d.com <http://redshift3d.com>
>      > domain and no others, you need the last one.
> 
> 
> 
>     _______________________________________________
>     squid-users mailing list
>     squid-users at lists.squid-cache.org
>     <mailto:squid-users at lists.squid-cache.org>
>     http://lists.squid-cache.org/listinfo/squid-users
>     <http://lists.squid-cache.org/listinfo/squid-users>
>