hello, everybody...
i'm newbie in shell script..
here i have a question want to ask you all, hope someone can give a hand to me and solve the problem

Question:

Write a shell program to find the given number is primary or not.

anyone know how to slove, please kindly send me a mail.
thank you very much..

What's a primary number? Is this your homework assignment?

yaya.. that is my homewrok assignment..because i'm really new in this script,do not have any idea to do it. so need some help here..

question description:

when user enter the number, it will define the number whether primary number or not. *primary number is 1,2,3,5,7,11,13,.... (cannot be devided by some number)

hope anyone can help me..
thanks..

Though I also don't know shell scripts, I would rather advise you to get the method of knowing that procedure from a maths teacher. There should be a calculation to know how to know this effectively then afterwards it will be easy to implement it in any language!

Do not expect LQ members to do your homework - you will learn much more by doing it yourself.

http://www.linuxquestions.org/rules.php

There are many algorithms for determining what you want. The most well known being the Sieve of Eratosthenes. It would do you well to understand the procedure BEFORE you try to develop code to do it for you! Once you've figured out HOW to do your own homework, you might be able to ask LQ about some script commands that will implement the algortihm.

Incidently, they are not primary numbers. They are called prime numbers.

I want to see the guy who codes that in bash!

I want to see him waiting for the results.

prime number is a number that is only divisible by one and itself.


may be small flaws in below algorithm but should basically work ....


prime=0 #just using as toggle 0=default(prime), 1=not prime
divisor=2 # start at 2 because all numbers are divis by 1

get number

# in while loop divisor cant be bigger than 1/2 number because
# well basic maths gives an answer to that

while (divisor <= number/2) and (prime=0)
remainder = number%divisor # where % returns the remainder of the division
if remainder=0
prime=1
end if
increment divisor
end while

if prime=1
print that number is not prime
else
print number is prime


I reckon I could write that (or something similar) in bash. I'm not gonna do homework for someone.

thanks you all reply..
i foind the solution already..


THANKS VERY MUCH