I guess, nothing is wrong, I was just thinking of a way for isolating a variable name from the rest of the regex, i.e. variable name is not terminated.
Is this possible?: [[:$ipv4:]] or I should do (?:$ipv4)?

In reply to Re^2: Defining your own regex character class by igoryonya
in thread Defining your own regex character class by igoryonya

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