1#! /bin/sh 2 3: 'This file is in the public domain, so clarified as of' 4: '2006-07-17 by Arthur David Olson.' 5 6case $#-$1 in 7 2-|2-0*|2-*[!0-9]*) 8 echo "$0: wild year: $1" >&2 9 exit 1 ;; 10esac 11 12case $#-$2 in 13 2-even) 14 case $1 in 15 *[24680]) exit 0 ;; 16 *) exit 1 ;; 17 esac ;; 18 2-nonpres|2-nonuspres) 19 case $1 in 20 *[02468][048]|*[13579][26]) exit 1 ;; 21 *) exit 0 ;; 22 esac ;; 23 2-odd) 24 case $1 in 25 *[13579]) exit 0 ;; 26 *) exit 1 ;; 27 esac ;; 28 2-uspres) 29 case $1 in 30 *[02468][048]|*[13579][26]) exit 0 ;; 31 *) exit 1 ;; 32 esac ;; 33 2-*) 34 echo "$0: wild type: $2" >&2 ;; 35esac 36 37echo "$0: usage is $0 year even|odd|uspres|nonpres|nonuspres" >&2 38exit 1 39