Class: Zip::File

Inherits:
CentralDirectory show all
Includes:
FileSystem
Defined in:
lib/zip/file.rb,
lib/zip/filesystem.rb

Overview

ZipFile is modeled after java.util.zip.ZipFile from the Java SDK. The most important methods are those inherited from ZipCentralDirectory for accessing information about the entries in the archive and methods such as get_input_stream and get_output_stream for reading from and writing entries to the archive. The class includes a few convenience methods such as #extract for extracting entries to the filesystem, and #remove, #replace, #rename and #mkdir for making simple modifications to the archive.

Modifications to a zip archive are not committed until #commit or #close is called. The method #open accepts a block following the pattern from File.open offering a simple way to automatically close the archive when the block returns.

The following example opens zip archive my.zip (creating it if it doesn't exist) and adds an entry first.txt and a directory entry a_dir to it.

require 'zip'

Zip::File.open("my.zip", Zip::File::CREATE) {
 |zipfile|
  zipfile.get_output_stream("first.txt") { |f| f.puts "Hello from ZipFile" }
  zipfile.mkdir("a_dir")
}

The next example reopens my.zip writes the contents of first.txt to standard out and deletes the entry from the archive.

require 'zip'

Zip::File.open("my.zip", Zip::File::CREATE) {
  |zipfile|
  puts zipfile.read("first.txt")
  zipfile.remove("first.txt")
}

ZipFileSystem offers an alternative API that emulates ruby's interface for accessing the filesystem, ie. the File and Dir classes.

Constant Summary collapse

CREATE =
true
SPLIT_SIGNATURE =
0x08074b50
ZIP64_EOCD_SIGNATURE =
0x06064b50
MAX_SEGMENT_SIZE =
3_221_225_472
MIN_SEGMENT_SIZE =
65_536
DATA_BUFFER_SIZE =
8192
IO_METHODS =
[:tell, :seek, :read, :eof, :close]
DEFAULT_OPTIONS =
{
  restore_ownership:   false,
  restore_permissions: false,
  restore_times:       false
}.freeze

Constants inherited from CentralDirectory

CentralDirectory::END_OF_CDS, CentralDirectory::MAX_END_OF_CDS_SIZE, CentralDirectory::STATIC_EOCD_SIZE, CentralDirectory::ZIP64_END_OF_CDS, CentralDirectory::ZIP64_EOCD_LOCATOR

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from FileSystem

#dir, #file

Methods inherited from CentralDirectory

#==, #each, #entries, #get_64_e_o_c_d, #get_e_o_c_d, #read_64_e_o_c_d, #read_central_directory_entries, #read_e_o_c_d, read_from_stream, #read_from_stream, #size, #start_buf, #write_to_stream, #zip64_file?

Constructor Details

#initialize(path_or_io, create = false, buffer = false, options = {}) ⇒ File

Opens a zip archive. Pass true as the second parameter to create a new archive if it doesn't exist already.


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# File 'lib/zip/file.rb', line 76

def initialize(path_or_io, create = false, buffer = false, options = {})
  super()
  options  = DEFAULT_OPTIONS.merge(options)
  @name    = path_or_io.respond_to?(:path) ? path_or_io.path : path_or_io
  @comment = ''
  @create  = create ? true : false # allow any truthy value to mean true

  if ::File.size?(@name.to_s)
    # There is a file, which exists, that is associated with this zip.
    @create = false
    @file_permissions = ::File.stat(@name).mode

    if buffer
      read_from_stream(path_or_io)
    else
      ::File.open(@name, 'rb') do |f|
        read_from_stream(f)
      end
    end
  elsif buffer && path_or_io.size > 0
    # This zip is probably a non-empty StringIO.
    read_from_stream(path_or_io)
  elsif @create
    # This zip is completely new/empty and is to be created.
    @entry_set = EntrySet.new
  elsif ::File.zero?(@name)
    # A file exists, but it is empty.
    raise Error, "File #{@name} has zero size. Did you mean to pass the create flag?"
  else
    # Everything is wrong.
    raise Error, "File #{@name} not found"
  end

  @stored_entries      = @entry_set.dup
  @stored_comment      = @comment
  @restore_ownership   = options[:restore_ownership]
  @restore_permissions = options[:restore_permissions]
  @restore_times       = options[:restore_times]
end

Instance Attribute Details

#commentObject

Returns the zip files comment, if it has one


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# File 'lib/zip/file.rb', line 72

def comment
  @comment
end

#nameObject (readonly)

Returns the value of attribute name


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# File 'lib/zip/file.rb', line 60

def name
  @name
end

#restore_ownershipObject

default -> false.


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# File 'lib/zip/file.rb', line 63

def restore_ownership
  @restore_ownership
end

#restore_permissionsObject

default -> false, but will be set to true in a future version.


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# File 'lib/zip/file.rb', line 66

def restore_permissions
  @restore_permissions
end

#restore_timesObject

default -> false, but will be set to true in a future version.


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# File 'lib/zip/file.rb', line 69

def restore_times
  @restore_times
end

Class Method Details

.add_buffer {|zf| ... } ⇒ Object

Same as #open. But outputs data to a buffer instead of a file

Yields:

  • (zf)

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# File 'lib/zip/file.rb', line 132

def add_buffer
  io = ::StringIO.new('')
  zf = ::Zip::File.new(io, true, true)
  yield zf
  zf.write_buffer(io)
end

.foreach(zip_file_name, &block) ⇒ Object

Iterates over the contents of the ZipFile. This is more efficient than using a ZipInputStream since this methods simply iterates through the entries in the central directory structure in the archive whereas ZipInputStream jumps through the entire archive accessing the local entry headers (which contain the same information as the central directory).


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# File 'lib/zip/file.rb', line 171

def foreach(zip_file_name, &block)
  ::Zip::File.open(zip_file_name) do |zip_file|
    zip_file.each(&block)
  end
end

.get_partial_zip_file_name(zip_file_name, partial_zip_file_name) ⇒ Object


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# File 'lib/zip/file.rb', line 187

def get_partial_zip_file_name(zip_file_name, partial_zip_file_name)
  unless partial_zip_file_name.nil?
    partial_zip_file_name = zip_file_name.sub(/#{::File.basename(zip_file_name)}\z/,
                                              partial_zip_file_name + ::File.extname(zip_file_name))
  end
  partial_zip_file_name ||= zip_file_name
  partial_zip_file_name
end

.get_segment_count_for_split(zip_file_size, segment_size) ⇒ Object


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# File 'lib/zip/file.rb', line 196

def get_segment_count_for_split(zip_file_size, segment_size)
  (zip_file_size / segment_size).to_i + (zip_file_size % segment_size == 0 ? 0 : 1)
end

.get_segment_size_for_split(segment_size) ⇒ Object


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# File 'lib/zip/file.rb', line 177

def get_segment_size_for_split(segment_size)
  if MIN_SEGMENT_SIZE > segment_size
    MIN_SEGMENT_SIZE
  elsif MAX_SEGMENT_SIZE < segment_size
    MAX_SEGMENT_SIZE
  else
    segment_size
  end
end

.open(file_name, create = false, options = {}) ⇒ Object

Similar to ::new. If a block is passed the Zip::File object is passed to the block and is automatically closed afterwards, just as with ruby's builtin File::open method.


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# File 'lib/zip/file.rb', line 120

def open(file_name, create = false, options = {})
  zf = ::Zip::File.new(file_name, create, false, options)
  return zf unless block_given?

  begin
    yield zf
  ensure
    zf.close
  end
end

.open_buffer(io, options = {}) {|zf| ... } ⇒ Object

Like #open, but reads zip archive contents from a String or open IO stream, and outputs data to a buffer. (This can be used to extract data from a downloaded zip archive without first saving it to disk.)

Yields:

  • (zf)

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# File 'lib/zip/file.rb', line 143

def open_buffer(io, options = {})
  unless IO_METHODS.map { |method| io.respond_to?(method) }.all? || io.kind_of?(String)
    raise "Zip::File.open_buffer expects a String or IO-like argument (responds to #{IO_METHODS.join(', ')}). Found: #{io.class}"
  end

  io = ::StringIO.new(io) if io.kind_of?(::String)

  # https://github.com/rubyzip/rubyzip/issues/119
  io.binmode if io.respond_to?(:binmode)

  zf = ::Zip::File.new(io, true, true, options)
  return zf unless block_given?

  yield zf

  begin
    zf.write_buffer(io)
  rescue IOError => e
    raise unless e.message == 'not opened for writing'
  end
end

.put_split_signature(szip_file, segment_size) ⇒ Object


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# File 'lib/zip/file.rb', line 200

def put_split_signature(szip_file, segment_size)
  signature_packed = [SPLIT_SIGNATURE].pack('V')
  szip_file << signature_packed
  segment_size - signature_packed.size
end

.save_splited_part(zip_file, partial_zip_file_name, zip_file_size, szip_file_index, segment_size, segment_count) ⇒ Object

TODO: Make the code more understandable


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# File 'lib/zip/file.rb', line 209

def save_splited_part(zip_file, partial_zip_file_name, zip_file_size, szip_file_index, segment_size, segment_count)
  ssegment_size  = zip_file_size - zip_file.pos
  ssegment_size  = segment_size if ssegment_size > segment_size
  szip_file_name = "#{partial_zip_file_name}.#{format('%03d', szip_file_index)}"
  ::File.open(szip_file_name, 'wb') do |szip_file|
    if szip_file_index == 1
      ssegment_size = put_split_signature(szip_file, segment_size)
    end
    chunk_bytes = 0
    until ssegment_size == chunk_bytes || zip_file.eof?
      segment_bytes_left = ssegment_size - chunk_bytes
      buffer_size        = segment_bytes_left < DATA_BUFFER_SIZE ? segment_bytes_left : DATA_BUFFER_SIZE
      chunk              = zip_file.read(buffer_size)
      chunk_bytes += buffer_size
      szip_file << chunk
      # Info for track splitting
      yield segment_count, szip_file_index, chunk_bytes, ssegment_size if block_given?
    end
  end
end

.split(zip_file_name, segment_size = MAX_SEGMENT_SIZE, delete_zip_file = true, partial_zip_file_name = nil) ⇒ Object

Splits an archive into parts with segment size

Raises:


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# File 'lib/zip/file.rb', line 231

def split(zip_file_name, segment_size = MAX_SEGMENT_SIZE, delete_zip_file = true, partial_zip_file_name = nil)
  raise Error, "File #{zip_file_name} not found" unless ::File.exist?(zip_file_name)
  raise Errno::ENOENT, zip_file_name unless ::File.readable?(zip_file_name)

  zip_file_size = ::File.size(zip_file_name)
  segment_size  = get_segment_size_for_split(segment_size)
  return if zip_file_size <= segment_size

  segment_count = get_segment_count_for_split(zip_file_size, segment_size)
  # Checking for correct zip structure
  ::Zip::File.open(zip_file_name) {}
  partial_zip_file_name = get_partial_zip_file_name(zip_file_name, partial_zip_file_name)
  szip_file_index       = 0
  ::File.open(zip_file_name, 'rb') do |zip_file|
    until zip_file.eof?
      szip_file_index += 1
      save_splited_part(zip_file, partial_zip_file_name, zip_file_size, szip_file_index, segment_size, segment_count)
    end
  end
  ::File.delete(zip_file_name) if delete_zip_file
  szip_file_index
end

Instance Method Details

#add(entry, src_path, &continue_on_exists_proc) ⇒ Object

Convenience method for adding the contents of a file to the archive


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# File 'lib/zip/file.rb', line 299

def add(entry, src_path, &continue_on_exists_proc)
  continue_on_exists_proc ||= proc { ::Zip.continue_on_exists_proc }
  check_entry_exists(entry, continue_on_exists_proc, 'add')
  new_entry = entry.kind_of?(::Zip::Entry) ? entry : ::Zip::Entry.new(@name, entry.to_s)
  new_entry.gather_fileinfo_from_srcpath(src_path)
  new_entry.dirty = true
  @entry_set << new_entry
end

#add_stored(entry, src_path, &continue_on_exists_proc) ⇒ Object

Convenience method for adding the contents of a file to the archive in Stored format (uncompressed)


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# File 'lib/zip/file.rb', line 310

def add_stored(entry, src_path, &continue_on_exists_proc)
  entry = ::Zip::Entry.new(@name, entry.to_s, nil, nil, nil, nil, ::Zip::Entry::STORED)
  add(entry, src_path, &continue_on_exists_proc)
end

#closeObject

Closes the zip file committing any changes that has been made.


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# File 'lib/zip/file.rb', line 372

def close
  commit
end

#commitObject

Commits changes that has been made since the previous commit to the zip archive.


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# File 'lib/zip/file.rb', line 346

def commit
  return if name.kind_of?(StringIO) || !commit_required?

  on_success_replace do |tmp_file|
    ::Zip::OutputStream.open(tmp_file) do |zos|
      @entry_set.each do |e|
        e.write_to_zip_output_stream(zos)
        e.dirty = false
        e.clean_up
      end
      zos.comment = comment
    end
    true
  end
  initialize(name)
end

#commit_required?Boolean

Returns true if any changes has been made to this archive since the previous commit

Returns:

  • (Boolean)

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# File 'lib/zip/file.rb', line 378

def commit_required?
  @entry_set.each do |e|
    return true if e.dirty
  end
  @comment != @stored_comment || @entry_set != @stored_entries || @create
end

#extract(entry, dest_path, &block) ⇒ Object

Extracts entry to file dest_path.


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# File 'lib/zip/file.rb', line 338

def extract(entry, dest_path, &block)
  block ||= proc { ::Zip.on_exists_proc }
  found_entry = get_entry(entry)
  found_entry.extract(dest_path, &block)
end

#find_entry(entry_name) ⇒ Object

Searches for entry with the specified name. Returns nil if no entry is found. See also get_entry


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# File 'lib/zip/file.rb', line 387

def find_entry(entry_name)
  selected_entry = @entry_set.find_entry(entry_name)
  return if selected_entry.nil?

  selected_entry.restore_ownership   = @restore_ownership
  selected_entry.restore_permissions = @restore_permissions
  selected_entry.restore_times       = @restore_times
  selected_entry
end

#get_entry(entry) ⇒ Object

Searches for an entry just as find_entry, but throws Errno::ENOENT if no entry is found.

Raises:

  • (Errno::ENOENT)

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# File 'lib/zip/file.rb', line 404

def get_entry(entry)
  selected_entry = find_entry(entry)
  raise Errno::ENOENT, entry if selected_entry.nil?

  selected_entry
end

#get_input_stream(entry, &a_proc) ⇒ Object

Returns an input stream to the specified entry. If a block is passed the stream object is passed to the block and the stream is automatically closed afterwards just as with ruby's builtin File.open method.


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# File 'lib/zip/file.rb', line 258

def get_input_stream(entry, &a_proc)
  get_entry(entry).get_input_stream(&a_proc)
end

#get_output_stream(entry, permission_int = nil, comment = nil, extra = nil, compressed_size = nil, crc = nil, compression_method = nil, size = nil, time = nil, &a_proc) ⇒ Object

Returns an output stream to the specified entry. If entry is not an instance of Zip::Entry, a new Zip::Entry will be initialized using the arguments specified. If a block is passed the stream object is passed to the block and the stream is automatically closed afterwards just as with ruby's builtin File.open method.


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# File 'lib/zip/file.rb', line 267

def get_output_stream(entry, permission_int = nil, comment = nil,
                      extra = nil, compressed_size = nil, crc = nil,
                      compression_method = nil, size = nil, time = nil,
                      &a_proc)

  new_entry =
    if entry.kind_of?(Entry)
      entry
    else
      Entry.new(@name, entry.to_s, comment, extra, compressed_size, crc, compression_method, size, time)
    end
  if new_entry.directory?
    raise ArgumentError,
          "cannot open stream to directory entry - '#{new_entry}'"
  end
  new_entry.unix_perms = permission_int
  zip_streamable_entry = StreamableStream.new(new_entry)
  @entry_set << zip_streamable_entry
  zip_streamable_entry.get_output_stream(&a_proc)
end

#glob(*args, &block) ⇒ Object

Searches for entries given a glob


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# File 'lib/zip/file.rb', line 398

def glob(*args, &block)
  @entry_set.glob(*args, &block)
end

#mkdir(entry_name, permission = 0o755) ⇒ Object

Creates a directory

Raises:

  • (Errno::EEXIST)

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# File 'lib/zip/file.rb', line 412

def mkdir(entry_name, permission = 0o755)
  raise Errno::EEXIST, "File exists - #{entry_name}" if find_entry(entry_name)

  entry_name = entry_name.dup.to_s
  entry_name << '/' unless entry_name.end_with?('/')
  @entry_set << ::Zip::StreamableDirectory.new(@name, entry_name, nil, permission)
end

#read(entry) ⇒ Object

Returns a string containing the contents of the specified entry


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# File 'lib/zip/file.rb', line 294

def read(entry)
  get_input_stream(entry, &:read)
end

#remove(entry) ⇒ Object

Removes the specified entry.


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# File 'lib/zip/file.rb', line 316

def remove(entry)
  @entry_set.delete(get_entry(entry))
end

#rename(entry, new_name, &continue_on_exists_proc) ⇒ Object

Renames the specified entry.


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# File 'lib/zip/file.rb', line 321

def rename(entry, new_name, &continue_on_exists_proc)
  found_entry = get_entry(entry)
  check_entry_exists(new_name, continue_on_exists_proc, 'rename')
  @entry_set.delete(found_entry)
  found_entry.name = new_name
  @entry_set << found_entry
end

#replace(entry, src_path) ⇒ Object

Replaces the specified entry with the contents of src_path (from the file system).


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# File 'lib/zip/file.rb', line 331

def replace(entry, src_path)
  check_file(src_path)
  remove(entry)
  add(entry, src_path)
end

#to_sObject

Returns the name of the zip archive


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# File 'lib/zip/file.rb', line 289

def to_s
  @name
end

#write_buffer(io = ::StringIO.new('')) ⇒ Object

Write buffer write changes to buffer and return


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# File 'lib/zip/file.rb', line 364

def write_buffer(io = ::StringIO.new(''))
  ::Zip::OutputStream.write_buffer(io) do |zos|
    @entry_set.each { |e| e.write_to_zip_output_stream(zos) }
    zos.comment = comment
  end
end