Perhaps something like this?

#!/usr/bin/perl
use strict;
use warnings;
while (my $line = <DATA>) {
        chomp $line;
    if ($line =~ m/in-addr/) {
        my @line = split(/\./, $line);
        if ($line[2] =~m/in-addr/) {
            process_line("$line[1]\." ."$line[0]\." . "0\." . "0"  . "
+\/24");
        } else {
            process_line("$line[2]\." . "$line[1]\." ."$line[0]\." . "
+0" . "\/16" );
        }
    } else {
        process_line($line);
    }
}

sub process_line {
    print shift . "\n";
    # do whatever...
}

__DATA__
250.26.192.in-addr.arpa,3
251.26.192.in-addr.arpa,3
252.26.192.in-addr.arpa,3
253.26.192.in-addr.arpa,3
254.26.192.in-addr.arpa,3
26.192.in-addr.arpa,2
hosangit.com
djzah.com
[download]

Output

192.26.250.0/16
192.26.251.0/16
192.26.252.0/16
192.26.253.0/16
192.26.254.0/16
192.26.0.0/24
hosangit.com
djzah.com
[download]

Hope that is helpful....

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.