Re: Sort directories by date

As RichardK wrote above:

"...It would have been much easier if you'd created the directory names as 'YYYYMMDD' then they would have sorted naturally with little effort...."

But i guess that it is like it is: You can't change that any more.

Here is another idea how to sort these directories that doesn't require any dark klingone maneuvers ;-)

#!/usr/bin/env perl

use strict;
use warnings;
use feature qw (say);

my @dates = qw{
  12112014
  01052015
  02202015
  03102015
  01012011
  04092015
  09092015
};

my %hash;

for (@dates) {
    my ( $m, $d, $y ) = unpack q(a2a2a4);
    $hash{qq($y$m$d)} = $_;
}

for ( sort { $a <=> $b } keys(%hash) ) {
    say $hash{$_};
}
__END__

karls-mac-mini:monks karl$ ./dirs.pl 
01012011
12112014
01052015
02202015
03102015
04092015
09092015
[download]

Please see also Path::Iterator::Rule, File::Basename, unpack, pack as well as perlpacktut.

Regards, Karl

ŤThe Crux of the Biscuit is the Apostropheť

Comment on Re: Sort directories by date Download Code

Replies are listed 'Best First'.
Re^2: Sort directories by date by Laurent_R (Canon) on Sep 29, 2015 at 20:44 UTC
Yeah, but why would you want to populate a hash and use sort, when you already have everything at hand and only need one very small extra step to find the max value? `#!/usr/bin/env perl use strict; use warnings; use feature qw (say); my @dates = qw{ 12112014 01052015 02202015 03102015 01012011 04092015 09092015 }; my $max_date = 0; my $result; for (@dates) { my $date = join "", reverse unpack q(a4a4); $result = $_ and $max_date = $date if $date > $max_date; } print $result;` [download] Update: fixed a mistake (missing `reverse`) in the `my $date = ...` code line above. Thanks to poj for pointing out the error.	[reply] [d/l] [select]
Re^3: Sort directories by date by karlgoethebier (Abbot) on Sep 30, 2015 at 10:16 UTC
"...why would you want to populate a hash and use sort..." Because i had no better idea :-( Update: No, wait: `use strict; use warnings; use feature qw (say); use List::Util qw(max); use Time::Piece; my @dates = qw{ 12112014 01052015 02202015 03102015 01012011 04092015 09092015 }; say localtime( max map { Time::Piece->strptime( $_, "%m%d%Y" )->epoch +} @dates ) ->strftime("%m%d%Y"); __END__ \Desktop\monks>other_idea.pl 09092015` [download] Best regards, Karl ŤThe Crux of the Biscuit is the Apostropheť	[reply] [d/l]