#!/bin/sh
# $Id: tm 1.1 1996/07/28 12:22:02 jerry Exp $
#
# tm - show current time in another timezone, or list timezones
# Usage: tm [timezone]

pager="more -d"			# pager, gives instructions on bottom line
cd /usr/lib/zoneinfo || exit	# Holds timezone files

case $# in

0)	# With no argument, shows the possible timezones.
	# All the "useful" files start with uppercase letters.
	# Find them, sort list, print in 3 columns, use pager:
	(echo '*** Use one of these timezones ***'
	find * -type f -name '[A-Z]*' -print | sort | pr -w80 -l1 -3 -t) |
	$pager
	exit 0
	;;

1)	case "$1" in
	[A-Z]*)	if [ -f "$1" ]
		then
			# show date
			TZ="$1" date
			exit 0
		else
			echo "$1??  For timezone list, use:  `basename $0`" 1>&2
			exit 2
		fi
		;;
	*)	echo "`basename $0`: Timezone Names All Start Uppercase." 1>&2
		exit 3
		;;
	esac
	;;

*)	echo "Usage: `basename $0` [timezone]" 1>&2
	exit 1
	;;

esac