The below code scans through a directory to gets all the ".plf" files and then stores the filenames as key and the lines in the files as values.My problem I see duplicate values for the filenames(keys) and values(lines in the files).Not sure what's going wrong?can anyone help?

my $start_dir;
my $file_name = "mjnload.cmm";
opendir(DIR, "$start_dir");
@plf_files = grep(/\.plf$/,readdir(DIR));
print "PLF FILES\n";
print "@plf_files\n";--->there are no duplicates 
closedir(DIR);
foreach my $plf (@plf_files) {
chomp($plf);
open my $match, '<',"$start_dir\\$plf" or die "could not open '$plf' $
+!";
my @file_lines = <$match>;
$Hash_filenames{$plf}=\@file_lines;
}

open my $hash, '>>', "hash.txt";
print $hash Dumper( \%Hash_filenames );
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