#!/usr/bin/perl -w
$ENV{'PATH'}="/usr/bin";

$threshold=94;

open(DIR, "df -k |") || die "Cannot fork df\n";
while (<DIR>) {
  next unless m|/cache\d|;
  @arr=split(/\s+|%/);
  if ( $arr[4] > $threshold ) {
    push(@dir,$arr[6]);
  }
}
close(DIR);

foreach $dir ( @dir ) {
  $n=(0..9, A..F)[rand(16)];
  print "$dir is more than ${threshold}% full, erasing files from 0${n}\n";
  system "find ${dir}/0${n} -type f | xargs rm";
}