#!/usr/bin/perl -w
# this code only partially tested

my($dir)    = $ARGV[0] ||'';
my($maxage) = $ARGV[1] ||0; $maxage = int $maxage;

die "Can't operate without a target directory spec.  Op aborted.\n"
   unless length $dir; # dir could be named "0"
die qq[No such directory "$dir"\n] unless -e $dir;
die "Need max allowed age spec for files.  Op aborted.\n"
   unless $maxage; # zero values and non-numeric values not accepted.

local *PDFDIR;
opendir(PDFDIR, $dir) or die $!;
my(@files) = grep(/\.pdf$/, readdir(PDFDIR));
closedir(PDFDIR) or warn $!;

print qq[Nothing to do.  No files present in "dir".\n] and exit unless @files;

foreach (@files) {
   print qq[Skipping directory "$dir/$_"\n] if -d $_;
   unlink $dir . '/' . $_ if int(-M $dir . '/' . $_) > $maxage
      or die qq[Can't unlink "$dir/$_"! $!];
   print qq[Deleted "$dir/$_"\n];
}

print "Done.\n\n" and exit;