Perl脚本：列出目录下所有的文件扩展名（后缀名）

#!/bin/perl
# Extension_filename_lister v0.1
# List all extension filenames without duplicate in a directory.

use strict;
use warnings;
use File::Find;

my %extname_list;

sub process_file {
??? my $cur_file = $_;?

??? # Ignore the directories . and ..
??? if ($cur_file eq "." || $cur_file eq "..") {
??????? return;
??? }

??? (my $ext_name) = ($cur_file =~ /.(w+)$/);

??? if (defined ($ext_name)) {
??????? $extname_list{$ext_name} = "Yes";
??? }

#??? print $cur_file,"n";
#??? print $ext_name,"n";
}

my @DIRLIST = (".");?
find(&;process_file,@DIRLIST);

print "Extension filenames:n"; foreach my $item (keys %extname_list) { ??? print $item,"n"; }