Ok, but I'd like to see what your try was (untested code follows).

#!/usr/bin/perl
use warnings;
use strict;
use Socket qw( inet_aton inet_ntoa);

# takes file paths as argument
for (@ARGV) {
    local $, = $/;
    open my $fh, '<', $_ or die $!;
    print map  { inet_ntoa($_) }
          sort { $a <=> $b }
          map  { chomp; inet_aton($_) }
          <$fh>;
    print $/;
    close $fh or die $!;
}
[download]

Update: pg++, thanks for catching my error. I'll leave this as it is, see pg's reply below.

After Compline,
Zaxo

This solution is actually on the right track.

The only mistake is that the author thought the result from inet_aton is a number, but it is not. In fact, the result returned is a string.

Simply modify that sort statement to:

sort {$a cmp $b}
[download]

Now this piece of code works properly (I tested the modified version).

If you are interested in details, inet_aton converts ascii address into a c structure in_addr, i.e.

struct in_addr {
    union {
        struct { u_char s_b1,s_b2,s_b3,s_b4; } S_un_b;
        struct { u_short s_w1,s_w2; } S_un_w;
        u_long S_addr;
    } S_un;
}
[download]

,which Perl interprets as a string, not an unsigned long.

My testing code:

use strict;
use Socket qw( inet_aton inet_ntoa);

local $, = $/;
print map  { inet_ntoa($_) }
      sort { $a cmp $b }
      map  { chomp; inet_aton($_) }
      <DATA>;
    print $/;
__DATA__
128.1.1.0
127
23.4.5.6
255.255.255.255
45.27.128.0
localhost
[download]

I had asked the original question regarding ip sorting. I
had to come back in here because I'd said that the man -g
worked fine. However, the list I'd tested it on wasn't
long enough for a real test. It does not work.

However pg's slight modification to Zaxo's original code
did the trick. Thanks very much.

My apologies for duplicating a thread. I've not been here before.

Thanks everyone!

I'm not a perl programmer, and my example would cause laughter for everyone else and embarrassment for me. :)

Here's the output from the untested code:

Argument "BmM-oM-5" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "CM-c\ng" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-Q\nM-Ri" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-QC^CM-B" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "BM-o^CI" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-QC\0M-2" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-Q\nM-Ri" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-QC^CM-L" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-OM-^\M-X$" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "D>Ge" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "E^AM-BJ" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
Argument "M-X^OM-\fM-^E" isn't numeric in sort at /usr/bin/ipsort line 13, <$fh> line 12.
66.109.239.181
67.227.10.103
209.10.210.105
209.67.3.194
66.239.3.73
209.67.0.178
209.10.210.105
209.67.3.204
207.156.216.36
68.62.71.101
69.1.194.74
216.15.140.133


Thanks for everyone's time.

A "natural sort" should fit this bill, so click that link to find several versions (including some rather simple and quite fast implementations).

Since TIMTOWTDI, you can also do this (slightly tested code)..

#!/usr/bin/perl
use strict;
use warnings;
use NetAddr::IP;

                # Beware large IP sets...
print join("\n", map { $_->addr } sort map { new NetAddr::IP $_ } <DAT
+A>), "\n";
 
 
__DATA__
10.1.5.2 
10.1.1.2
10.1.0.1
10.1.1.0
10.1.1.1
10.1.5.1
[download]

Best regards

-lem, but some call me fokat

sort -g does the job fine. I thought surely I looked at that
and it didn't work for me. I'm not so lazy that I
can't read a man page, I just overlooked this.

Thanks