use strict;
my $directory = "c:\\";

opendir( DIR, $directory )
  || die "Unable to open directory - $!\n";

my @files = grep /\.pdb/, readdir( DIR );
closedir( DIR );


foreach my $file (@files) {
    
	open( FH, "$directory\\$file" )
     
 || die "Unable to open $file - $!\n";
    
while( <FH> ) {
        
       
        
    }
    close( FH );
}