H g/./m0 g//a\ hello world # lines beginning with a `#' should be ignored g/hello /# including in global commands \ s/lo/p!/\ a\ order\ .\ # and in the command list \ i\ caos\ .\ -1s/l/L u u 17,33g/[A-I]/-1d\ +1c\ hello world\ .\ 47 ;d # don't change current address if no match g/xxx/1d ;j g/heLp! world//caos/d\ -;/order/;d # to be undone g/./s//x/g u w out.o