Re: Problems evaluating a user supplied regex using eval (boo)

this line from perlvar about $& should assist :

This variable is read-only and dynamically scoped to the current BLOCK

Guess what an eval counts as?

This will also affect the $n variables.

If you plan on matching only, you might take a look at evaling the creation of the regex, something like (off the top of my head) :

eval ($re=qr/foobar/) || warn $@;
[download]

if (eval ($re=qr/quuzy/)) {
  # manipulate
} else {
   #blargh! bad re
}
[download]

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Re: Re: Problems evaluating a user supplied regex using eval (boo) by Popcorn Dave (Abbot) on Apr 24, 2002 at 18:50 UTC
Thanks for the reply! So since eval is scoped to it's block, then am I correct in assuming I could do something along the lines of `eval { $my_text =~$regex # where $regex is m/ab\|(cd)/ for example print $&; print $1, $2 # if defined }` [download] and then $& will hold the value of the match, and $1 and $2 will be accessable? My understanding of this, and please correct me if I'm wrong, is that since eval is dynamically scoped, as long as my code is blocked between {} I'm okay.	[reply] [d/l]

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Re: Re: Problems evaluating a user supplied regex using eval (boo)
by Popcorn Dave (Abbot) on Apr 24, 2002 at 18:50 UTC

So since eval is scoped to it's block, then am I correct in assuming I could do something along the lines of

eval {
      $my_text =~$regex # where $regex is m/ab|(cd)/ for example
      print $&;
      print $1, $2 # if defined
      }
[download]

and then $& will hold the value of the match, and $1 and $2 will be accessable?

My understanding of this, and please correct me if I'm wrong, is that since eval is dynamically scoped, as long as my code is blocked between {} I'm okay.

[reply]
[d/l]