素で shift と間違えたorz...
>>837 訂正だ。
perl -le 'print + ( split /aaa/, "000aaa111aaa222")[-1] '
perl -le 'print + ( "000aaa111aaa222" =~ /.*(\d{3})$/ )'
perl -le 'print + ( unpack "A3" x 5, "000aaa111aaa222" )[-1] '
perl -le 'print + ( unpack "@*X3A3", "000aaa111aaa222" ) '
perl -le 'print + ( substr "000aaa111aaa222" , -3 )'