Your description and examples aren't enough to to deduce a regex from them. You should try to define precisely what you want to allow or not. This could look like that: 
A valid ref spec is a string that starts 
with the literal 'element ', and is followed by

* Either a star '*' OR by m/-dir(ectory)? \S+/
                    OR by m/-file \S+/
* then by a label

A label is ...

[download]

Once you know what you actually want to match, you can translate that into a regex quite easily: 

my $re = qr{
   element \s
      (
        \*
      | -dir(ectory)? \S+
      | -file \S+
      )
   # Label:
   \w+
}x;

[download]

You should also handle special cases special, ie don't try to munge them into your regex, but rather make an extra path to check for special cases.

In reply to Re: Help with regular expressions by moritz
in thread Help with regular expressions by KarthikK

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