(golf) Recursively delete empty directories from a tree

Hi folks. Today I had to write script that would delete all the empty directories in a directory tree recursively. Ie, removing any empty leaf dirs, and then moving up and removing the next layer if it is now empty, etc.

I thought that there must be a nice neat compact perlish way to do this, but it seemed to elude me. Anyway, the code I came up with is below, I'm wondering how compact this can be golfed down to by the folks out there that are good at golf. Requirements are to take a list of root dirs on the command line, delete any empty dirs, and then print out the number of dirs removed and the number kept. Ill accept anything that matches /D:\d+\s+F:\d+/ as the output string. It should die if there any errors removing the dirs, and the code need not worry about circular directories due to symlinks or the like. Have fun. :-) (You can assume there are no hidden or system files lurking in the tree, thanks davis for raising this issue.)

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

my $deleted=0;
my $keep=0;
$|++;
sub recurse {
    my $dir=shift;

    chdir $dir or die "chdir $dir:$!";
    my $dirname=cwd;

    #print "$dirname\n";


    my @dirs;
    my @files;

    for my $name (glob '*') {
        next unless $name=~/[^.]/;
        if (-d $name) {
            push @dirs,$name
                if recurse($name);
        } else {
            push @files,$name;
        }
    }

    chdir "..";
    unless (@dirs or @files) {
        print "X: $dirname\n";
        rmdir $dir or warn "$dirname:$!";
        $deleted++;
    } else {
        print   "k: $dirname (d: " 
              . scalar(@dirs)
              . " | f: ".scalar(@files).")\n";
        $keep++;
    }
    return @dirs+@files;
}


recurse $_ for @ARGV;
print "Deleted $deleted directories, kept $keep directories\n";
[download]

---
demerphq

_{First they ignore you, then they laugh at you, then they fight you, then you win.

-- Gandhi}

Comment on (golf) Recursively delete empty directories from a tree Select or Download Code

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Re: (golf) Recursively delete empty directories from a tree by Abigail-II (Bishop) on Feb 18, 2004 at 14:08 UTC
This one doesn't count directories, and might break if the directories have funny characters in them. It doesn't use much Perl either, but it's waaaaaaaaaaaaaay shorter than yours: `find @ARGV -type d -depth \| xargs rmdir`; [download] If you modify it to: `find @ARGV -type d -depth \| xargs rmdir 2>&1 \| wc -l`; [download] it'll tell you the amount of directories not removed. Abigail	[reply] [d/l] [select]
Re: Re: (golf) Recursively delete empty directories from a tree by Anonymous Monk on Feb 19, 2004 at 05:23 UTC
if you have the GNU text utilities most of them have a '-0' type option to seperate filenames with nulls. `find . -type d -depth -print0 \| xargs -0 prog` [download] which helps alot with the funky character problem. also there's the '-exec' option to find. `find . -type d -depth -exec rmdir -- {} \;` [download] which (i think) bypasses the shell so funky characters are no problem. the '--' option is handy to turn off further argument processing so a directory like '-r' isn't taken as a flag.	[reply] [d/l] [select]
Re: (golf) Recursively delete empty directories from a tree by halley (Prior) on Feb 18, 2004 at 15:26 UTC
Requirements are to take a list of root dirs on the command line, delete any empty dirs {...} and the code need not worry about circular directories due to symlinks or the like. It's often seen as bad form to invoke a lot of system commands which are likely to fail, but it seems to me that with these requirements, I could just `rmdir()` everything in sight, and if it failed to rmdir, then it was clearly not a leaf directory. `@_=@ARGV; push@_,glob("$_/")for@_; @_=grep{-d}reverse@_; $t=@_;rmdir$_&&$d++for@_; print"D:$d F:",$t-$d,$/;` [download] Update: added the requisite reporting, though still not trying very hard to reduce my handicap. I did notice that `glob("$_/")` appeared to break on directory names with spaces in them, at least here at work across a Samba-supplied directory. I haven't looked into that further. -- `[ e d @ h a l l e y . c c ]`	[reply] [d/l] [select]
Re: (golf) Recursively delete empty directories from a tree by borisz (Canon) on Feb 18, 2004 at 15:09 UTC
Here is my first try: `#!/usr/bin/perl use File::Find; my ( %h, $k, $d ); find( sub { $h{$File::Find::name} = 0 if -d $_; $h{$File::Find::dir}++ if -f _; }, $ARGV[0] ); chdir $ARGV[0]; !$h{$_} ? $d += rmdir: $k++ for ( sort { length($b) <=> length($a) } k +eys %h ); print "Deleted $d directories, kept $k directories\n";` [download] Boris	[reply] [d/l]
Re: (golf) Recursively delete empty directories from a tree by zentara (Cardinal) on Feb 18, 2004 at 19:49 UTC
How about this one? It could be even shorter if you remove the warning. `#!/usr/bin/perl use File::Find; finddepth sub { return if $_ eq "." or $_ eq ".."; return unless -d; rmdir($_); if($! =~ /not empty/){warn "$File::Find::name $!"} }, @ARGV;` [download] UPDATE: `#!/usr/bin/perl use File::Find; finddepth sub { return if (! -d) or ($_ eq '.'\|'..'); rmdir($_)}, @ARGV;` [download] I'm not really a human, but I play one on earth. flash japh	[reply] [d/l] [select]
Re: Re: (golf) Recursively delete empty directories from a tree by greenFox (Vicar) on Feb 18, 2004 at 23:30 UTC
Your solutions don't meet demerphq's specification for printing out a tally of directories kept or removed... I made it shorter any-way :) `use File::Find; finddepth sub {(!-d or /^.{1,2}$/)\|\|rmdir($_)},@ARGV;` [download] I wonder what else a day that begins with me posting code to a golf thread will have in store grin -- Do not seek to follow in the footsteps of the wise. Seek what they sought. -Basho	[reply] [d/l]
Re: Re: Re: (golf) Recursively delete empty directories from a tree by zentara (Cardinal) on Feb 19, 2004 at 16:39 UTC
`finddepth sub {(!-d or /^.{1,2}$/)\|\|rmdir($_)},@ARGV;` [download] didn't run for me, I needed to separate the rmdir with ; `use File::Find; finddepth sub {(!-d or /^.{1,2}$/);rmdir},@ARGV;` [download] or with a print `use File::Find; finddepth sub {(!-d or /^.{1,2}$/);rmdir; warn $File::Find::name,$! if $! =~ /not empty/},@ARGV;` [download] I'm not really a human, but I play one on earth. flash japh	[reply] [d/l] [select]
Re: Re: Re: Re: (golf) Recursively delete empty directories from a tree by greenFox (Vicar) on Feb 19, 2004 at 23:54 UTC
Re: Re: Re: Re: Re: (golf) Recursively delete empty directories from a tree by zentara (Cardinal) on Feb 20, 2004 at 16:53 UTC
Re: (golf) Recursively delete empty directories from a tree by rinceWind (Monsignor) on Feb 18, 2004 at 16:27 UTC
Sounds remarkably like the example in my recent post. Did you think about VMS's multiversioning I wonder? -- I'm Not Just Another Perl Hacker	[reply]
Re: Re: (golf) Recursively delete empty directories from a tree by halley (Prior) on Feb 18, 2004 at 17:07 UTC
You can't version a directory in VMS, I think. It's been a while, so correct me if I'm wrong. And since he's not interested in removing -f files, or directories which contain them, I think this is a bit different from any `1 while unlink()` idiom. -- `[ e d @ h a l l e y . c c ]`	[reply] [d/l]