yearistype.sh revision 273439 
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