http://www.perlmonks.org?node_id=521694

kulls has asked for the wisdom of the Perl Monks concerning the following question:

Greetings,
I'm reusing the node directory listings in hash and i got a list of directories like ca1, ca2,ca13,ca9,ca4 and so on .
I'll be grateful, if anyone give me a sorted directory list like ca1,ca2...ca9,ca10,ca11 and so on.
Update :
In this directory listings in hash node, i guess they constructing a hash based on each directory. So i need to sort the directories before building a hash.
Can anyone please give me a solution?
-kulls

Replies are listed 'Best First'.
Re: sorting out directories
by Tanktalus (Canon) on Jan 07, 2006 at 07:39 UTC

    Check out the Sort::Naturally module - it should do what you want. Getting the sort function to do this isn't hard, but it's not entirely straight-forward, either. At least not until you see the 'trick' (which is to separate out the letters from the numbers and find a way to sort on them separately - one way is to use an intermediate string where you insert leading zeros - ca1 becomes ca01, for example). And, of course, understand the trick. ;-) Sort::Naturally encapsulates this in a way that makes it easy even for more advanced monks to not get it wrong.

[reply]
Re: sorting out directories
by sk (Curate) on Jan 07, 2006 at 08:22 UTC
    Tanktalus's suggestion is a better to handle this problem. But if you want something quick and dirty, you can do something like this - 

    #!/usr/bin/perl -w

use strict;

my $base = "ca";

my @dirs = map { $base . int (rand 100) } (1..10);

# Instead of matching for $base (ca) you can also match characters etc
+. This approach works for simple things and can get complex quickly
my @sorted = sort { $a->[0] cmp $b->[0] ||
                    $a->[1] <=> $b->[1] } map { [/($base)(\d+)/] } @di
+rs;

@sorted = map { $_->[0] . $_->[1] } @sorted;

print $_, $/ for (@dirs);
print $/;
print $_, $/ for (@sorted);

    [download]

    Output

    ca58
ca43
ca98
ca83
ca11
ca59
ca54
ca92
ca69
ca30

ca11
ca30
ca43
ca54
ca58
ca59
ca69
ca83
ca92
ca98

    [download]
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Re: sorting out directories
by saintmike (Vicar) on Jan 07, 2006 at 07:21 UTC
    Use the sort function.
[reply]
Re: sorting out directories
by planetscape (Chancellor) on Jan 08, 2006 at 00:56 UTC
[reply]

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