Prime Factors Kata in Bash with Roundup

primes-test.sh

#!/usr/bin/env roundup

describe "prime factors"

it_succeeds_for_two() {
	test "$(./primes.sh 2)" == "2"
}

it_succeeds_for_three() {
	test "$(./primes.sh 3)" == "3"
}

it_succeeds_for_four() {
	test "$(./primes.sh 4)" == "2 2"
}

it_succeeds_for_five() {
	test "$(./primes.sh 5)" == "5"
}

it_succeeds_for_six() {
	test "$(./primes.sh 6)" == "2 3"
}

it_succeeds_for_eight() {
	test "$(./primes.sh 8)" == "2 2 2"
}

it_succeeds_for_nine() {
	test "$(./primes.sh 9)" == "3 3"
}

it_succeeds_for_a_big_one() {
	test "$(./primes.sh 245893)" == "23 10691"
}

primes.sh

#!/usr/bin/env bash

rem=$1
i=2
stop_at=$(echo "sqrt ( $1 )" | bc -l)
stop_at=${stop_at/.*}

while [ $i -le $stop_at ]; do
	while [ $rem -gt $i -a $(($rem % $i)) == 0 ]; do
		echo -n "$i "
		rem=$(($rem / $i))
	done

	if [ $i == 2 ]; then
		i=3
	else
		i=$((i + 2))
	fi
done

echo $rem