Yesterday, on the Chatterbox someone asked what a ".chm" file was. I looked it up in the registry and told him.

With so many file extensions in use, it would seem like a common request. So I present this Perl function to automate this lookup.

—John

use strict;
use warnings;
use Win32::TieRegistry 0.20 (Delimiter=>"/");

sub get_file_association ($) {
   my $x= shift;
   my $reg= $Registry->{"HKEY_CLASSES_ROOT/$x//"}  or return;
   # this usually refers to another entry.
   $reg &&= $Registry->{"HKEY_CLASSES_ROOT/$reg//"} if $x =~ /^\./;
   return $reg;
   }

    
# print get_file_association ('.chm');
foreach (@ARGV) {
   print $_, '=>', (get_file_association($_) || "NOT KNOWN"), "\n";
   }

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In reply to Windows file extensions by John M. Dlugosz

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