Re^3: [ Natural Sort ]: Sorting a string with numbers

The whole program is a bit complex and does a bunch of stuff that isn't relavent to this issue, but I've cut out everything but this section that shows the problem I'm having.

#!/usr/bin/perl -w

use strict;

my @h = ( qw(
                psapp1
                psapp
                psapp2
                psepapp1
                psepapp
                psepapp2
                psimgprod
                pspappuat
                pswebapp2
                pswebapp
              ) );

my @h_sorted = @h[
        map { unpack "N", substr($_,-4) }
        sort
        map {
            my $key = $h[$_];
            $key =~ s[(\d+)][ pack "N", $1 ]ge;
            $key . pack "N", $_
        } 0..$#h
];
    

foreach (@h_sorted) { print "$_\n"; };
[download]

When I run this program, with my Perl (This is perl, v5.8.6 built for darwin-thread-multi-2level), I get:

psapp
psapp1
psapp2
psepapp1
psepapp2
psepapp
psimgprod
pspappuat
pswebapp2
pswebapp
[download]

The "psapp" items sort properly, but the "psepapp" and "pswebapp" ones show the problem I'm asking about. Thanks! -s-

Comment on Re^3: [ Natural Sort ]: Sorting a string with numbers Select or Download Code

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Re^4: [ Natural Sort ]: Sorting a string with numbers (fix) by tye (Sage) on Sep 18, 2005 at 03:25 UTC
Yeah, that's the problem I discussed elsewhere. Here's a simple fix: `#!/usr/bin/perl -w use strict; my @h = ( qw( psapp1 psapp psapp2 psepapp1 psepapp psepapp2 psimgprod pspappuat pswebapp2 pswebapp ) ); my @h_sorted = @h[ map { unpack "N", substr($_,-4) } sort map { my $key = $h[$_]; $key =~ s[(\d+)][ pack "N", $1 ]ge; $key . pack "CNN", 0, 0, $_ } 0..$#h ]; foreach (@h_sorted) { print "$_\n"; };` [download] This inserts 5 nul bytes which prevents the problem. 1 nul byte is enough to fix this specific case. 4 fixes all cases except for the possibility of "x0" sorting before "x". 5 fixes all cases (provided you don't have nul bytes in your strings). - tye	[reply] [d/l]
Re^5: [ Natural Sort ]: Sorting a string with numbers (fix) by blueflashlight (Pilgrim) on Sep 18, 2005 at 17:41 UTC
You are a hero. Thank you so much ... I even understand your solution, which, in itself is amazing. :-)	[reply]