Perl : File::Path / File::Copy 删掉中间全空的目录

见：Learning Perl Challenge: Remove intermediate directories


#!/usr/bin/perl
use strict;
use warnings;
use File::Path qw(remove_tree);
use File::Copy qw(move);
my ($dir) = @ARGV;
short_dir($dir);
sub short_dir {
    my ($start, $now) = @_;
    return unless(-d $start);
    $now ||= $start;
    my @subnodes = glob("$now/*");
    my @subdirs = grep { -d $_ } @subnodes;
    if($#subdirs>0){
        short_dir($_) for @subdirs;
    }elsif($#subdirs==0){
        short_dir($start, $subdirs[0]);
    }else{
        return if($start eq $now);
        move($_, "$start/") for @subnodes;  
        my @dirs = grep { -d $_ } glob("$start/*");
        remove_tree($dirs[0]);
    }
}