use Regexp::English;
my $re = Regexp::English
        -> start_of_line
        -> literal('mail xmlfeedback -s ')
        -> remember
        -> zero_or_more
            -> non_newline
        -> end
        -> end_of_line;
print $re;
__END__
(?^:^mail\ xmlfeedback\ \-s\ ((?:(?s)[^\n]*)$))
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