#!/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]