Someone had populated a single directory on our Sun file server with a couple million files, and I wanted to get some sense of the performance hit on reading the directory -- i.e. any sort of timing info on how long it would take to scan it all. 
perl -le 'opendir(D,"huge_directory");
  while($_=readdir D) {
   $t = time()-$^T;
   $e++ if ( $t!=$prev );
   if($n and $e==15){ print $n; $n=$e=0 }
   $n++; $prev=$t
  }'

[download]

The idea was simply to report how many iterations of "readdir" would finish within each 15-second interval. This seemed to work, but it struck me as crude. Suggestions for improvement?

In reply to How to time a directory scan by graff

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