From: Chuck Remes <cremes.devlist@...>
Date: 2011-09-26T01:22:34+09:00
Subject: FileUtils head-scratcher...

In one of my projects I need to move all files and subdirectories in a particular directory up on level.

e.g. mv * ..

When I wrote this in Ruby using FileUtils, it works the first time but subsequent runs fail and I don't understand why. The error doesn't make sense because the file/directory it is complaining about is always already there.

Here's the code:

require 'fileutils'

def makedir(name)
 FileUtils.mkdir name unless File.exists?(name) && File.directory?(name)
end

makedir('dir')
Dir.chdir('dir') do
 makedir('subdir')
 Dir.chdir('subdir') do
   5.times { |i| FileUtils.touch i.to_s }
   makedir('subsubdir')
   Dir.chdir('subsubdir') do
     5.times { |i| FileUtils.touch i.to_s }
   end
 end

 subdir = Dir.glob("subdir/*")
 FileUtils.mv subdir, '.', :verbose => true
end

The first run works. The second run fails.


cremes$ ruby a.rb
mv subdir/0 subdir/1 subdir/2 subdir/3 subdir/4 subdir/subsubdir .
cremes$ ruby a.rb
mv subdir/0 subdir/1 subdir/2 subdir/3 subdir/4 subdir/subsubdir .
An exception occurred running a.rb
    File exists - . (Errno::EEXIST)

Backtrace:
                { } in FileUtils.mv at /Volumes/spiff/cremes/dev/ruby/rubinius
                                       /lib/18/fileutils.rb:500
  { } in FileUtils.fu_each_src_dest at /Volumes/spiff/cremes/dev/ruby/rubinius
                                       /lib/18/fileutils.rb:1402
 { } in FileUtils.fu_each_src_dest0 at /Volumes/spiff/cremes/dev/ruby/rubinius
                                       /lib/18/fileutils.rb:1411
                          Array#each at kernel/bootstrap/array.rb:66
        FileUtils.fu_each_src_dest0 at /Volumes/spiff/cremes/dev/ruby/rubinius
                                       /lib/18/fileutils.rb:1409
         FileUtils.fu_each_src_dest at /Volumes/spiff/cremes/dev/ruby/rubinius
                                       /lib/18/fileutils.rb:1400
                       FileUtils.mv at /Volumes/spiff/cremes/dev/ruby/rubinius
                                       /lib/18/fileutils.rb:495
            { } in Object#__script__ at a.rb:19
                           Dir.chdir at kernel/common/dir.rb:68
                   Object#__script__ at a.rb:8
    Rubinius::CodeLoader#load_script at kernel/delta/codeloader.rb:65
    Rubinius::CodeLoader.load_script at kernel/delta/codeloader.rb:107
             Rubinius::Loader#script at kernel/loader.rb:618
               Rubinius::Loader#main at kernel/loader.rb:772



How do I get this to work *every* time?

cr