Regex matching by scalars in perl

Question

I am using regular expression using scalars here. First time though. I will put the code. It should be self evident

#!/usr/bin/perl



my $regex = "PM*C";

my $var = "PM_MY_CALC";



 if($var =~ m/$regex/){

    print "match \n";

 }



 else{



    print "no match\n";

 }

The output that I get is "no match"..

am i missing something obvious here? obviously It did not match any other stuff.. so just made both the regex and the variable to be checked equal.. still no match.

I have tried doing this too..

 if($var =~ $regex ){

based on some search from perlMonks.

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Answer 1

am i missing something obvious here?

You're missing how regular expressions work. They don't work how shell filename expansion works.

Your regex uses * which means "zero of more of the preceding character". So M* matches nothing, 'M', 'MM', 'MMM', etc.

You wanted to match "PM" followed by any number of any character followed by "C". The correct regex for that is PM.*C. A dot (.) means "match (almost) any character" and (as I said above) * matches zero or more of that.

I recommend reading the Perl Regular Expression tutorial.

Regex matching by scalars in perl

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