## Using Perl Net::IP to Manipulate IPv4 Addresses

In a previous post, I demonstrated a Korn shell script which determined the subnet mask for a range of IPv4 addresses. Perl has a module called Net::IP which provides a number of functions which can be used to manipulate IPv4 (and also IPv6) addresses to provide the same information and a lot more besides. For example, the following code outputs a lot of information about a classless prefix: use Net::IP; my \$ip = new Net::IP (‘10.1.1.0/24’) or die (Net::IP::Error()); print ("IP : ".\$ip->ip()."n"); print ("Sho : ".\$ip->short()."n"); print ("Bin : ".\$ip->binip()."n"); print ("Int : ".\$ip->intip()."n"); print ("Mask: ".\$ip->mask()."n"); print ("Last:

## Calculating Prime Numbers using Perl

Definition of a prime number: A prime number is defined by any number that is only dividable by 1 or itself. Except for 2 which is a prime, a prime number is always odd (2n+1) Here is a Perl script which outputs all the prime numbers between 0 and 10000: #!/usr/bin/perl my \$UPPER = 10000; my \$sieve = “”; print “2n”; for (my \$guess = 3; \$guess < = \$UPPER; \$guess+=2) { next if vec(\$sieve,\$guess,1); print "\$guessn"; for (my \$mults = \$guess * \$guess; \$mults