Regular Expressions

[nisha]

Hello PerlMonks, I need help with this small problem. I have a variable called

$filepath="c:\\reports";
i also have 
$string="c:\\reports";
i want to do a pattern match here like
if ( $string=~m/$filepath/)
{
  print "Found";
}
But here within / / is it possible to give a variable name?? How do we
+ specify a variable name inside / / in pattern matching.

Please help

[l.frankline]

Hi,

You can use variable in the pattern matching if you are using regular expressions, but it has a problem, if the variable contains text of special characters, then it is better to use \Q \E

Example:

$string=~m/\Q$filepath\E/

Warning: \Q \E should be used when you are not using regular expressions in a variable.

Regards

Franklin

Edit: g0n - corrected code tags

[murugu]

Hi nisha,

Yes you can give a variable name inside the regular expression.

[blazar]

Did you try? What did you get? Short answer: yes, you can put a variable in there. It's interpolated just like in doubly quoted strings. But then you may and should be interested in \Q (and \E). What is this stuff I'm babbling about, anyway? Well you can find out in the same place where you would have also found an answer to your own questions, i.e. precisely in the docs!

[tbone1]

One minor issue. You have:

$filepath="c:\\reports";

However, the double-quotes will convert the '\\' to a '\', since '\' is a meta-character. You might try using single quotes instead:

$filepath='c:\\reports';

Hope this helps.

[blazar]

However, the double-quotes will convert the '\\' to a '\', since '\' is a meta-character. You might try using single quotes instead:

1. I think that's exactly what that he wants. But then he should just use forward slashes, since they work just the same even under Windows,
2. '\' is a meta charachter in single quoted strings too:

$ cat foo
print '\\';
$ perl -l foo
\

[jesuashok]

Hi

you can do that.