#!/usr/bin/perl -w

# Read from standard input a list of filenames, and
# report a sorted list of extensions and filenames
# (most common ones first).

# The format is "name count", where "count" is the number of appearances.
# "name" usually begins with a "." followed by the name of the extension.
# In the case where the filename has no extension, the name begins with "/"
# followed by the entire basename.

%extensions = ();

while (<>) {
   if (m/\.([^.\/]+)$/) {
      $type = $1;
      chomp($type);
      $type = ".$type";
      if (defined($extensions{$type})) { $extensions{$type}++; }
      else                             { $extensions{$type} = 1; }
   } elsif (m!/([^/]+)$!) {
      $filename = $1;
      chomp($filename);
      $filename = "/$filename";
      if (defined($extensions{$filename})) { $extensions{$filename}++; }
      else                                 { $extensions{$filename} = 1; }
   }
}

foreach $entry (sort {$extensions{$b} <=> $extensions{$a}} keys %extensions) {
  print "${entry}  $extensions{$entry}\n";
}