Re^2: creating qr from existing regex

i figured it out. The issue was that when i created the $re variable, it was adding the slashes. by using just what was inside the slashes of the original string, i managed to get it to work

            if(index($_[0],"qr/") >= 0){ 
                $_[0] =~s/qr[\/](.*?)([^\\])[\/](i?)$/$1$2/s;
                print $fh Dumper($_[0]);
                if($3=='i'){
                    $_[0] = qr/$_[0]/i;
                }else{
                    $_[0] = qr/$_[0]/;
                }
                print $fh Dumper($_[0]);
            }
[download]

Comment on Re^2: creating qr from existing regex Download Code

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Re^3: creating qr from existing regex by poj (Abbot) on Feb 08, 2018 at 19:08 UTC
Maybe use split `my $string = '/.*uba$/i'; my @f = split '/',$string; my $qr = ($f[-1] eq 'i') ? qr/$f[1]/i : qr/$f[1]/; my $cursor = $collection->query( { name=> $qr });` [download] poj	[reply] [d/l]
Re^4: creating qr from existing regex by Bobert1234 (Novice) on Feb 09, 2018 at 06:54 UTC
that could work in general, but the input is dynamic, and someone might put in an escaped slash, i.e. \/	[reply]
Re^5: creating qr from existing regex by AnomalousMonk (Bishop) on Feb 09, 2018 at 14:47 UTC
`c:\@Work\Perl\monks>perl -wMstrict -le "my $string = '/.u\/ba$/i'; ;; my $rx = eval 'qr' . $string; print $rx; print 'A: match' if 'u/Ba' =~ $rx; ;; my $ry = qr{ \A foo $rx }xms; print $ry; print 'B: match' if 'foolubatU/bA' =~ $ry; " (?i-xsm:.u/ba$) A: match (?msx-i: \A foo (?i-xsm:.u/ba$) ) B: match` [download] Update:* Of course, given that you're dealing with user-supplied data and considering the danger of an injection attack, maybe one should think twice about an eval-based approach. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^5: creating qr from existing regex by Your Mother (Archbishop) on Feb 09, 2018 at 18:30 UTC
In addition to what AnomalousMonk said. Plain regular expressions can be constructed to be DoS attacks; even unintentionally. The handling varies from Perl version to version and I am pretty sure regular expressions were impossible to interrupt with a timeout historically so the "attack" was impossible to guard against. I have no idea if this is still the case in newer versions or when it changed if it did.	[reply]


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