Nested quantifiers in regex

Hi,
Can anyone please help me to avoid the following perl error: "Nested quantifiers in regex; marked by <-- HERE "

The code snippet causing the error is:
$string="whatever";
$doesntmatter="something";
$var="+ / *";
$string=~ s/$doesntmatter/$var/g;

Thanks in advance

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Comments

nipper

I tried those 4 lines (alone) on my server it they worked fine.
Even when I used strict.

Not certain what you are seeing.

herald10

sorry try these four lines:

$string="whatever";
$doesntmatter="something";
$var="c++";
$string=~ s/$var/$doesntmatter/g;

Johnny

$var="c++";

is that supposed to be a string, or are you using the regex + symbol?

its best to you single quotes or qr to assign a string for regex use.

try

$var = qr (c\+\+);

John Cuiuli

herald10

John,
Thanks. Using the single quotes did the trick. What if I need to read the value from a text file? In the below set of lines $var comes from a file and the value is again C++ .

$string="whatever";
$doesntmatter="something";
$var=<INPUT>;
$string=~ s/$var/$doesntmatter/g;

Thanks

Johnny

thats a good question, and i have a good answer for that.

Maybe someone has a more direct answer for you.

But i can only think of running through the text for all regex symbols and escaping them first, before you apply the your regex in question

IE

/\+/\\+/

maybe the pack command could you out here. I dont really know off the top of my head, hopefully someone else knows about this situation.

John Cuiuli

Adam Stoller

How about:

$string="whatever";
$doesntmatter="something";
chomp($var=<INPUT>);
$string=~ s/\Q$var\E/$doesntmatter/g;

--fish
Senior Consultant, Quotient Inc.
http://www.quotient-inc.com

Johnny

> thats a good question, and i have a good answer for that.

I just read my last post...

I meant to say that I didnt have a good answer!! Smiley Happy

John Cuiuli

Johnny

There you go...

fish got it for you....

out of the perlre perldoc

\Q quote (disable) pattern metacharacters till \E

John Cuiuli