#!/usr/bin/perl -w
use strict;

if (!$ARGV[0]){
        die "Usage: $0 filename.txt\n";
}

my $basename=$ARGV[0];
if ($basename=~s/\.txt$//){
        my $endname="$basename-";
        open(my $input,"$ARGV[0]")||die "I can't read $ARGV[0]\n";
                my @all=<$input>;
        close $input;
        foreach(@all){
                if (/POST DATE\s+(\d+\/\d+\/\d+)/){
                        my $basedate=$1;
                        my @info=split(/\//,$basedate);
                        foreach(@info){
                                s/^0+//;
                                $endname.="0" unless $_>9;
                                $endname.=$_;
                        }
                }
        }
        system("mv \"$ARGV[0]\" \"$endname.txt\"");

}
else{
        die "Filenames must end in .txt\n";
}