#!/bin/sh -
#
#   Print a sequence of numbers, separated by newlines.
#   See the usage message below for details.
#   Works on FreeBSD.  Does not work on Solaris.
#
#   This script is in the public domain.
#   Use freely.  No warranty.
#

Usage()
{
	echo "Usage:  ${0##*/} <last> [<first> [<digits>]]" >&2
	echo "Print a sequence of numbers from <first> to <last> (inclusive)," >&2
	echo "separated by newlines, using a minimum of <digits> digits for" >&2
	echo "each number (zero-padded if necessary)." >&2
	echo "The default for <first> is 1.  The default for <digits> is the" >&2
	echo "number of digits of <last>." >&2
	exit 1
}

if [ $# -lt 1 -o $# -gt 3 ]; then
	Usage
fi

GetNum()
{
	case "$1" in
		*[^0-9]*|"")
			Usage
			;;
	esac
	echo "$1"
}

N_LAST=$(GetNum "$1")

if [ $# -gt 1 ]; then
	N_FIRST=$(GetNum "$2")
else
	N_FIRST=1
fi

if [ $# -gt 2 ]; then
	N_DIGITS=$(GetNum "$3")
else
	N_DIGITS=${#N_LAST}
fi

exec jot -w "%0${N_DIGITS}d " - $N_FIRST $N_LAST

#--