1 while s/^(\d*)0\n\1.$/$1/mg || s/^(\d*)\n\1.*$/$1/mg;

[download]
There's a reason I put [1] there instead of your ".". Consider what happens when you have the following: 
10010
100100
100101

[download]
The last two lines will be merged, creating 
10010
10010

[download]
And your code will strip that final 0 from both lines, creating "1001". Wrong. You must ensure that it's a 1. Can't be "any".

-- Randal L. Schwartz, Perl hacker

In reply to Re: Re: Merge CIDRs by merlyn
in thread Merge CIDRs by merlyn

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