Help for this page
s{^\Qmail xmlfeedback -s \E(.*)$}{mail -s $1 xmlfeedback}sgx; s{^mail xmlfeedback -s ("feed invalid for agent \d+")\s*$}{mail -s $1 +xmlfeedback}sgx;
use Regexp::English; my $re = Regexp::English ... print $re; __END__ (?^:^mail\ xmlfeedback\ \-s(\"feed\ invalid\ for\ agent\ (?:\d+)\")(?: +\s*)$)