#!/bin/rc

switch($#*) {
case 0
	awk '{printf("%-5d\t%s\n",NR,$0)}'
case 1 
	awk '{printf("%-5d\t%s\n",NR,$0)}' < $1
case *
	echo 'usage: catn file' >[1=2]
	echo '       catn < file' >[1=2]
	echo '       cat file | catn' >[1=2]
}