How to unzip a zipped folder with rubyzip

Question

I know how to retrieve the contents of a normal zip-file with rubyzip. But i got trouble unzipping the contents of a zipped folder and i hope any of u guys can help me out.

this is the code i use to unzip:

Zip::ZipFile::open(@file_location) do |zip|
 zip.each do |entry|
  next if entry.name =~ /__MACOSX/ or entry.name =~ /\.DS_Store/ or !entry.file?
  logger.debug "#{entry.name}"
  @data = File.new("#{Rails.root.to_s}/tmp/#{entry.name}")
 end
end

entry.name gives me the name of the file inside the zip-file. This works perfectly with a normal zipfile. But when the zipfile is created from a folder, then the name of the entries are something like: test-folder/test.pdf. When i then try to create the file, it tells me the file can not be found. This is probably because it is inside the "test"-folder that is inside the zip.

If i check the entry to be a folder, no folder can be found. So i thought the solution to be to read the entry as a stream and then save it as a file. It is easy to get the entry-stream, but how do I save it as a file? This is what i got so far.

Zip::ZipFile::open(@file_location) do |zip|
 zip.each do |entry|
  next if entry.name =~ /__MACOSX/ or entry.name =~ /\.DS_Store/ or !entry.file?
  logger.debug "#{entry.name}"
  @data = entry.get_input_stream.read
  # How do i create a file from a stream?
 end
end

Basically my question is: how can i create a file from a stream? Or is there an easier approach to this than mine?

===EDIT=== I use paperclip to store the files.

Locris

Answer 1

I found that a simpler approach based on jhwist's worked ok:

Zip::File.open(@file_location) do |zipfile|
  zipfile.each do |entry|
    # The 'next if...' code can go here, though I didn't use it
    unless File.exist?(entry.name)
      FileUtils::mkdir_p(File.dirname(entry.name))
      zipfile.extract(entry, entry.name) 
    end
  end
end

The conditional is obviously optional, but without it the code will raise an error if it tries to overwrite an existing file.

Retaliation

This approach is not preserving the permissions of the files. How can I preserve the permissions after extracting? – Subtropics

That's weird that zip.mkdir does not work as mkdir_p though entry.name includes the whole path. Because of this we have to use FileUtils ( – Leotaleotard

Answer 2

I think your problem is not whether you need to write a file from a stream or not. Basically, if you call File.new it will create a new IO-Stream (File is a subclass of IO). Therefore whatever you want to do with the stream from the zipfile should also work with a regular file.

When you say

When i then try to create the file, it tells me the file can not be found

I think what happens is that the parent-directory for the file you want to create does not exist (in your case the test-folder). What you want to do is something like that (not tested):

Zip::ZipFile::open(@file_location) do |zip|
 zip.each do |entry|
   next if entry.name =~ /__MACOSX/ or entry.name =~ /\.DS_Store/ or !entry.file?
   logger.debug "#{entry.name}"
   FileUtils::mkdir_p(File.dirname(entry.name)) # might want to check if it already exists    
   @data = File.new("#{Rails.root.to_s}/tmp/#{entry.name}")
 end
end

Cresting

I tried your code, but it only creates the parent folder of the entry in the root of my project. I still can't access the entry it self. It is actually an Errno::ENOENT - i thought i should mention this. thx tho – Locris

Answer 3

I solved it by using a stream and creating a StringIO. Here is the code

Zip::ZipFile::open(@file_location) do |zip|
 zip.each do |entry|
  next if entry.name =~ /__MACOSX/ or entry.name =~ /\.DS_Store/ or !entry.file?

  begin
   # the normal unzip-code
  rescue Errno::ENOENT
   # when the entry can not be found
   @data = entry.get_input_stream.read
   @file = StringIO.new(@data)
   @file.class.class_eval { attr_accessor :original_filename, :content_type }
   @file.original_filename = entry.name
   @file.content_type = MIME::Types.type_for(entry.name)

   # save it / whatever
  end
 end
end

Locris

That first line should be: Zip::ZipFile.open(@file_location) do |zip| – Bane