#!/usr/bin/perl --
use strict;
use warnings;
use Data::Dump qw/ dd /;
my @in = qw/
1020300000_XXXXXXXXX_20160707193000.TXT
1020300000_XXXXXXXXX_20160707170000.TXT
1020300000_XXXXXXXXX_20160707190000.TXT
/;
my $final = GiveMeItTheThingIWant( \@in );
dd( $final, \@in );
sub GiveMeItTheThingIWant {
    my( $in ) = @_;
    my @ordered = 
    map { $$_[1] }
    sort { $$a[0] cmp $$b[0] }
    map { 
#~         my( $left, $right ) = $_ =~ m{^([^_]+)_[^_]+_([^_]+)};
        my( $left, $middle, $right , $txt ) = split /[_\.]/, $_;
        [ $right, $_ ];
    }
    @{$in};
    
    return $ordered[0];
#~     return '1020300000_XXXXXXXXX_20160707170000.TXT';
}
__END__
[download]

Hello friend, thanks for the tip. It has helped me .. but I own many other files as for example: 981139804_ABCDEF12345678765463565E_28062016172508.TXT 981139804_ABCDEF12345678765463565E_28062016192508.TXT 981139804_ABCDEF12345678765463565E_28062016112508.TXT 981139804_ABCDEF12345678765463565E_28062016102508.TXT 981139804_ABCDEF12345678765463565E_28062017102508.TXT 971305332_XXXXXX12345678765463565E_28062011102508.TXT 971305332_AAAAAAAA12345678765463565E_28062011102508.TXT 971305332_CCCC12345678765463565E_28062011102508.TXT 971305332_CCCC12345678765463565E_28062020102508.TXT And when that occurs, it is only returned to a number, that is, I needed to return ordering the first column and the last.

Your OP data has the date in YYYYMMDD format which is simple to sort. The data here is in DDMMYYYY format which is trickier. Which is correct and, more importantly, is the data consistent?

Cheers,

JohnGG

Thats funny leoberbert

Ok thats easier to deduce from, its easier to understand the question if you take one file name, break it into parts, and label the parts so they match the word descriptions ... I'll be back in 1min