Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot
 
PerlMonks  

Re^3: RegEx Matching, Loop Breaking...

by AnomalousMonk (Abbot)
on May 28, 2013 at 20:05 UTC ( #1035715=note: print w/ replies, xml ) Need Help??


in reply to Re^2: RegEx Matching, Loop Breaking...
in thread RegEx Matching, Loop Breaking...

The reason taking the quotemeta out fixed the problem is that a quotemeta-ed string that contained  \W characters will, in general (there may be some oddball corner cases), not regex-match with itself after the string has been double-quote-ishly interpolated into a regex. The reason is that after a string is quotemeta-ed, something like  '\-' in the quotemeta-ed string is literally a backslash-hyphen sequence of characters, but this sequence in a regex only matches a hyphen leaving the backslash in the quotemeta-ed string unmatched.

>perl -wMstrict -le "my $s = 'a-b c*d'; my $qm_s = quotemeta $s; print qq{raw: '$s' quotemeta-ed: '$qm_s'}; ;; printf qq{%s equal \n}, $qm_s eq $qm_s ? '' : 'NOT '; printf qq{%s match \n}, $qm_s =~ /$qm_s/ ? '' : 'NO '; " raw: 'a-b c*d' quotemeta-ed: 'a\-b\ c\*d' equal NO match


Comment on Re^3: RegEx Matching, Loop Breaking...
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1035715]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others meditating upon the Monastery: (5)
As of 2015-08-01 03:10 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (285 votes), past polls