#!/bin/sh 
# Unix Shell version of a Prime Number Finder
# haplo@mindstab.net

odd=3
sqr=4
max=2
i=3
if [ ! $1 ] ; then
	echo "primes.sh [Max number]"
	exit
fi

MAX=$1
if [ $MAX -le 0 ] ; then
	echo "Max must be a valid number"
	exit
fi

while [ $i -lt $MAX ] ;
do
	isP=1
	x=3
	while [ $x -le $max -a $isP != 0 ] ;
	do
		isP=`expr $i % $x`
		x=`expr $x + 2`
		
	done
	if [ $isP != 0 ] ; 
	then
		echo "$i"
	fi
	if [ $i -ge $sqr ] ;
	then
		max=`expr $max + 1`
		odd=`expr $odd + 2`
		sqr=`expr $odd + $sqr - 2`
	fi
	
	i=`expr $i + 2`;
done