my %searchs = (
    stringa => sub { print "matched on stringa\n"; },
    stringb => sub { print "regex on string b\n";  },
    stringc => sub { print "C match\n";            },
);

my %compiled =
    map { $_ => qr/\Q$_/ }
    keys %searchs
;

while (<DATA>) {
    chomp;
    if (/^\*{3} (.+)/) {
        print "Found the following strings within body $1\n";
        next;
    }

    for my $search_string (keys %searchs) {
        if (/$compiled{ $search_string }/) {
            $searches{ $search_string }->();
        }
    }
}