Shell Script 印出質數

來源: http://advantage-bash.blogspot.com/2012/03/finding-prime-numbers.html


#!/bin/bash

#for displaying prime number between zero and given number

for (( i=2; i<=$1; i++ ));do
l=$(factor $i | cut -d : -f 1)
r=$(factor $i | cut -d : -f 2 | sed 's/ //g')
if (( $l == $r ));then
echo $i
fi
done