Storing regexps in variables

[pando]

Hi all, I have a problem with regexp and I have no idea how to overcome this. I have some experience with regexp but this is beyond my knowledge. Looks like ++ from my substring is the problem, but still, how can I do this regexp ?

$substr="libstdc++"
$string="compat-libstdc++.so.6"
print "Found" if ( $string =~ /$substr/ );

I get an error:

Nested quantifiers in regex; marked by <-- HERE in m/compat-libstdc++ 
+<-- HERE }/ at

[davorg]

A '+' has a special meaning in a regular expression (it means "one or more of the preceding character"). Two of them in succession is a regex syntax error.

Your problem is that you have regex metacharacters that you want to be treated as normal characters. That is what the \Q escape sequence is for.

print "Found" if $string =~ /\Q$substr/;

[Util]

I think you left out the 'd' in the second line of your example code;
Did you mean to say $string="compat-libstdc++.so.6"; ?

The other monks are correct about quotemeta and \Q to fix your regex problem. Also, consider using index, which is designed for just finding one string in another.

print "Found" if index( $string, $substr ) != -1;

[andye]

Take a look at quotemeta.

Hope that helps, andye

[pando]

Yes indeed, it was a typo error and I missed a 'd' in my message.

Anyway, thank you information was really helpful and did the trick.