For the second issue generally /e (evaluate) is used, but you need it twice. Remember to quote the $ in the string for $replace, or use single quotes so Perl doesn't try to interpolate $1:

my $replace = '$1';
$string =~ s/a+(b+)a+/$replace/eeg;

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DWIM is Perl's answer to Gödel

In reply to Re: How to apply modifiers to a substitution via variable? by GrandFather
in thread How to apply modifiers to a substitution via variable? by lokiloki

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