Even numbers

paraiso · 05-15-2005, 12:14 PM

Hi !

I have been trying to write a shell script to print even numbers and odd numbers but I get lost with the modulus and how to write the expression. Is there someone who could demonstrate an example of printing even or odd numbers ?

Thank you in advance

juanbobo · 05-15-2005, 12:38 PM

If the (number % 2) is > 0, then the number is odd, else it is even.

paraiso · 05-15-2005, 01:42 PM

The problem I have with this shell script is to write the correct syntax. I know that in order to get my even numbers I have to divide them by % 2 to see if the remaining is zero but then to write it I get lost with bash script.

Help!

juanbobo · 05-15-2005, 03:28 PM

This is probably the best tutorial on Bash, you should be able to find any answers there. I'd like to help you more, I don't know what problems you are having in particular.

http://www.tldp.org/LDP/abs/html/

david_ross · 05-15-2005, 03:31 PM

How about this for syntax:

Code:

rossy - trigger - Sun May 15 21:32:42
~> num=4
rossy - trigger - Sun May 15 21:32:47
~> if [ $num -eq $(($num/2*2)) ];then echo $num is even;else echo $num is odd;fi
4 is even
rossy - trigger - Sun May 15 21:32:48
~> num=3
rossy - trigger - Sun May 15 21:32:50
~> if [ $num -eq $(($num/2*2)) ];then echo $num is even;else echo $num is odd;fi
3 is odd