: argtype lists all em mnemonics that have an argument type equal to : one of the letters specified in the argument case x$# in x2) ;; x*) echo "Usage: $0 argtypes " 1>&2 exit 1 ;; esac ed -s $2 << A 1,/^\$/d 1,/^\$/d 1,/^\$/g/^\(...\) [$1].*/s//\\1/gp A