You're most welcome!
Yes, Komodo appears to just be alerting you about <DATA>, but should certainly know better, since there's a __DATA__ section.
Try the following:
use strict;
use warnings;
use File::stat;
chomp( my @fileNames = <*.bak> );
my @sortedFileNames = map $_->[0],
sort { $b->[1] <=> $a->[1] }
map { my $stat = stat $_; [ $_, $stat->mtime ] }
grep /^backup_\d\d_\d\d_\d{4}.bak$/, @fileNames;
shift @sortedFileNames;
if (@sortedFileNames) {
print "$_\n" for @sortedFileNames;
#unlink @sortedFileNames;
}
This stats each file for the modification time, using it in the sort. Also, note that a file glob's used to read directory files...