Re: Challenge Problem: Merging Network Addresses

Use Net::CIDR's cidr2range, sort the ranges, combine the ones that are overlapping or adjacent, then use range2cidr to go back.

-- Randal L. Schwartz, Perl hacker

update Shoot, I totally missed cidradd in the same module, which does precisely that!

$ perl
use Net::CIDR qw(cidradd);
print join (", ", cidradd(qw{
209.152.214.112/30
209.152.214.116/31
209.152.214.118/31
})), "\n"
^D
209.152.214.112/29
$ perl
use Net::CIDR qw(cidradd);
print join (", ", cidradd(qw{
209.152.214.112/31
209.152.214.116/31
209.152.214.118/31
})), "\n"
^D
209.152.214.112/31, 209.152.214.116/30
[download]

Comment on Re: Challenge Problem: Merging Network Addresses Download Code

Replies are listed 'Best First'.
(tye)Re: Challenge Problem: Merging Network Addresses by tye (Sage) on Oct 12, 2001 at 01:45 UTC
See also (tye)Re: converting complex netrange to cidr notation for my version of range2cidr which I think might be simpler than Net::CIDR's, though you may want to change to returning a list instead of displaying a list. - tye (but my friends call me "Tye")	[reply]
Re: Challenge Problem: Merging Network Addresses by Dominus (Parson) on Oct 12, 2001 at 02:25 UTC
That's a great answer. Thanks a lot. I can believe that `Net::CIDR` is the fastest way to do this in Perl. Unfortunately, it may be too slow. My test program took about 2.5 minutes to process test file `nm5.in`. The C program is about 120-150 times faster. That's a bummer. I was hoping that there would be a Perl solution that would be fast enough to be useful. -- Mark Dominus Perl Paraphernalia	[reply]
Re: Re: Challenge Problem: Merging Network Addresses by tachyon (Chancellor) on Oct 12, 2001 at 04:42 UTC
I was hoping that there would be a Perl solution that would be fast enough to be useful Of course if you patched the module with XS and your C code there would be :-) Just a random thought to increase your workload for the benefit of everyone (except perhaps you). cheers tachyon s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print	[reply]
Re: Challenge Problem: Merging Network Addresses by Dominus (Parson) on Oct 12, 2001 at 21:10 UTC
Says tachyon: Of course if you patched the module with XS and your C code there would be :-) Not really. The C program is a complete program that solves this one specific problem. There's nowhere in the `Net::CIDR` interface to 'patch'; the module doesn't do what this program does, and this program doesn't implement any of the functions that `Net::CIDR` does. Even if I did put it in, there wouldn't be any benefit. At present, you could compile my program and then use: `#!/usr/bin/perl system("mjd-merge-blocks inputfile > outputfile");` [download] Then you could call it a "Perl solution", but it wouldn't really be one. Hacking my code into `Net::CIDR` wouldn't be a "Perl solution" either. -- Mark Dominus Perl Paraphernalia	[reply] [d/l]


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