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in reply to sorting ip octets

Hmmm...

my @ips = qw( 127.0.0.1 10.129.30.5 10.129.30.2 255.255.255.255 10.109.30.5 142.222.130.23 10.109.1.1 142.222.87.30 ); my @sorted = map { $_->[1]; } sort { $a->[0] cmp $b->[0] } map { [ sprintf("%03d.%03d.%03d.%03d", split /\./), $_ ] } @ips; print map { $_.$/ } @sorted;
Is that reasonable? (I did test it - it seems to work for the example above.)

Update: Change the @sorted line to this also works:

my @sorted = map { $_->[1]; } sort { $a->[0] <=> $b->[0] } map { [ sprintf("%03d%03d%03d%03d", split /\./), $_ ] } @ips;

This one uses numerical comparison... not really sure which one would be faster. I like the first one better if only because it looks to me like I'm doing what I say I'm doing, where as this one looks more like I'm faking it.

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Re^2: sorting ip octets
by Anonymous Monk on Feb 16, 2005 at 19:04 UTC
    thanks it works but I open it from a txt file and read it line by line.

    thank you for the help

      Normally, we recommend reading files and dealing with them line-by-line. That doesn't really work for sorting. So just read your text file into @ips, chomping as appropriate, and then sort as above. All I was helping you with was the sorting of ip octets, not the reading of a file or writing to a file. Those are left as an excersise for the reader. (I never knew how much fun it was to say that until I left university... :-})

        I appreciate all the help you have given me.