class Minitar::Input

Wraps a Minitar::Reader with convenience methods and wrapped stream management; Input only works with data streams that can be rewound.

Attributes

tar[R]

Returns the Reader object for direct access.

Public Class Methods

Minitar::Input.each_entry(io) → enumerator click to toggle source
Minitar::Input.each_entry(io) { |entry| block } → obj

Iterates over each entry in the provided input. This wraps the common pattern of:

Minitar::Input.open(io) do |i|
  inp.each do |entry|
    # ...
  end
end

If a block is not provided, an enumerator will be created with the same behaviour.

# File lib/minitar/input.rb, line 49
def self.each_entry(input)
  return to_enum(__method__, input) unless block_given?

  Input.open(input) do |stream|
    stream.each do |entry|
      yield entry
    end
  end
end
Minitar::Input.new(io) → input click to toggle source
Minitar::Input.new(path) → input

Creates a new Input object. If input is a stream object that responds to read, then it will simply be wrapped. Otherwise, one will be created and opened using Kernel#open. When Input#close is called, the stream object wrapped will be closed.

An exception will be raised if the stream that is wrapped does not support rewinding.

# File lib/minitar/input.rb, line 70
def initialize(input)
  @io = if input.respond_to?(:read)
    input
  else
    ::Kernel.open(input, "rb")
  end

  unless Minitar.seekable?(@io, :rewind)
    raise Minitar::NonSeekableStream
  end

  @tar = Reader.new(@io)
end
Minitar::Input.open(io) → input click to toggle source
Minitar::Input.open(io) { |input| block } → obj

With no associated block, Input.open is a synonym for Input.new. If the optional code block is given, it will be given the new Input as an argument and the Input object will automatically be closed when the block terminates (this also closes the wrapped stream object). In this instance, Input.open returns the value of the block.

# File lib/minitar/input.rb, line 18
def self.open(input)
  stream = new(input)

  if block_given?
    # This exception context must remain, otherwise the stream closes on
    # open even if a block is not given.
    begin
      yield stream
    ensure
      stream.close
    end
  else
    stream
  end
end

Public Instance Methods

close() click to toggle source

Closes both the Reader object and the wrapped data stream.

# File lib/minitar/input.rb, line 156
def close
  @io.close
  @tar.close
end
closed?() click to toggle source

Returns false if the wrapped data stream is open.

# File lib/minitar/input.rb, line 148
def closed?
  @io.closed?
end
each()
Alias for: each_entry
each_entry() { |entry| ... } click to toggle source

When provided a block, iterates through each entry in the archive. When finished, rewinds to the beginning of the stream.

If not provided a block, creates an enumerator with the same semantics.

# File lib/minitar/input.rb, line 88
def each_entry
  return to_enum unless block_given?

  @tar.each do |entry|
    yield entry
  end
ensure
  @tar.rewind
end
Also aliased as: each
extract_entry(destdir, entry, options = {}, &) click to toggle source

Extracts the current entry to destdir. If a block is provided, it yields an action Symbol, the full name of the file being extracted (name), and a Hash of statistical information (stats).

The action will be one of:

:dir

The entry is a directory.

:file_start

The entry is a file; the extract of the file is just beginning.

:file_progress

Yielded every 4096 bytes during the extract of the entry.

:file_done

Yielded when the entry is completed.

The stats hash contains the following keys:

:current

The current total number of bytes read in the entry.

:currinc

The current number of bytes read in this read cycle.

:entry

The entry being extracted; this is a Reader::EntryStream, with all methods thereof.

# File lib/minitar/input.rb, line 118
def extract_entry(destdir, entry, options = {}, &) # :yields action, name, stats:
  stats = {
    current: 0,
    currinc: 0,
    entry: entry
  }

  # extract_entry is not vulnerable to prefix '/' vulnerabilities, but it
  # is vulnerable to relative path directories. This code will break this
  # vulnerability. For this version, we are breaking relative paths HARD by
  # throwing an exception.
  #
  # Future versions may permit relative paths as long as the file does not
  # leave +destdir+.
  #
  # However, squeeze consecutive '/' characters together.
  full_name = entry.full_name.squeeze("/")

  if /\.{2}(?:\/|\z)/.match?(full_name)
    raise SecureRelativePathError, "Path contains '..'"
  end

  if entry.directory?
    extract_directory(destdir, full_name, entry, stats, options, &)
  else # it's a file
    extract_file(destdir, full_name, entry, stats, options, &)
  end
end

Private Instance Methods

extract_directory(destdir, full_name, entry, stats, options) { |:dir, full_name, stats| ... } click to toggle source
# File lib/minitar/input.rb, line 173
def extract_directory(destdir, full_name, entry, stats, options)
  dest = File.join(destdir, full_name)

  yield :dir, full_name, stats if block_given?

  if Minitar.dir?(dest)
    begin
      FileUtils.chmod(entry.mode, dest)
    rescue
      nil
    end
  else
    File.unlink(dest.chomp("/")) if File.symlink?(dest.chomp("/"))

    FileUtils.mkdir_p(dest, mode: entry.mode)
    FileUtils.chmod(entry.mode, dest)
  end

  if options.fetch(:fsync, true)
    fsync_dir(dest)
    fsync_dir(File.join(dest, ".."))
  end
end
extract_file(destdir, full_name, entry, stats, options) { |:file_start, full_name, stats| ... } click to toggle source
# File lib/minitar/input.rb, line 197
def extract_file(destdir, full_name, entry, stats, options)
  destdir = File.join(destdir, File.dirname(full_name))
  FileUtils.mkdir_p(destdir, mode: 0o755)

  destfile = File.join(destdir, File.basename(full_name))

  File.unlink(destfile) if File.symlink?(destfile)

  # Errno::ENOENT
  FileUtils.chmod(0o600, destfile) rescue nil # standard:disable Style/RescueModifier

  yield :file_start, full_name, stats if block_given?

  File.open(destfile, "wb", entry.mode) do |os|
    loop do
      data = entry.read(4096)
      break unless data

      stats[:currinc] = os.write(data)
      stats[:current] += stats[:currinc]

      yield :file_progress, full_name, stats if block_given?
    end

    if options.fetch(:fsync, true)
      yield :file_fsync, full_name, stats if block_given?
      os.fsync
    end
  end

  FileUtils.chmod(entry.mode, destfile)

  if options.fetch(:fsync, true)
    yield :dir_fsync, full_name, stats if block_given?

    fsync_dir(File.dirname(destfile))
    fsync_dir(File.join(File.dirname(destfile), ".."))
  end

  yield :file_done, full_name, stats if block_given?
end
fsync_dir(dirname) click to toggle source
# File lib/minitar/input.rb, line 163
def fsync_dir(dirname)
  # make sure this hits the disc
  dir = IO.open(dirname, "rb")
  dir.fsync
rescue # ignore IOError if it's an unpatched (old) Ruby
  nil
ensure
  dir&.close rescue nil # standard:disable Style/RescueModifier
end