Module: Omnizip::Formats::Cpio

Defined in:
lib/omnizip/formats/cpio.rb,
lib/omnizip/formats/cpio/entry.rb,
lib/omnizip/formats/cpio/reader.rb,
lib/omnizip/formats/cpio/writer.rb,
lib/omnizip/formats/cpio/constants.rb,
lib/omnizip/formats/cpio/bounded_io.rb

Overview

CPIO archive format support

Provides read and write access to CPIO archives in multiple formats:

  • newc (SVR4 new ASCII format) - Most common, used in initramfs
  • CRC (newc with CRC checksums)
  • ODC (Old portable ASCII format)

CPIO is commonly used for:

  • Linux initramfs/initrd
  • RPM package contents
  • Unix system backups

Examples:

Create CPIO archive

Omnizip::Formats::Cpio.create('archive.cpio') do |cpio|
  cpio.add_directory('files/')
end

Extract CPIO archive

Omnizip::Formats::Cpio.extract('archive.cpio', 'output/')

Defined Under Namespace

Modules: Constants Classes: BoundedIO, Entry, Reader, Writer

Class Method Summary collapse

Class Method Details

.create(path, format: :newc) {|writer| ... } ⇒ String

Create CPIO archive

Examples:

Create newc format archive

Omnizip::Formats::Cpio.create('archive.cpio') do |cpio|
  cpio.add_file('kernel.img')
  cpio.add_directory('modules/')
end

Create with CRC checksums

Omnizip::Formats::Cpio.create('archive.cpio', format: :crc) do |cpio|
  cpio.add_directory('initramfs/')
end

Parameters:

  • path (String) —

    Output CPIO file path

  • format (Symbol) (defaults to: :newc) —

    CPIO format (:newc, :crc, :odc)

Yields:

  • (writer) —

    Block for adding files/directories

Yield Parameters:

  • writer (Writer) —

    CPIO writer

Returns:

  • (String) —

    Path to created archive



50
51
52
53
54
55
56
 
# File 'lib/omnizip/formats/cpio.rb', line 50

def create(path, format: :newc)
  writer = Writer.new(path, format: format)

  yield writer if block_given?

  writer.write
end

.extract(cpio_path, output_dir) ⇒ Object

Extract CPIO archive

Examples:

Extract archive

Omnizip::Formats::Cpio.extract('archive.cpio', 'output/')

Parameters:

  • cpio_path (String) —

    Path to CPIO file

  • output_dir (String) —

    Output directory



99
100
101
102
103
 
# File 'lib/omnizip/formats/cpio.rb', line 99

def extract(cpio_path, output_dir)
  open(cpio_path) do |cpio|
    cpio.extract_all(output_dir)
  end
end

.info(path) ⇒ Hash

Get archive information

Examples:

Get archive info

info = Omnizip::Formats::Cpio.info('archive.cpio')
puts "Format: #{info[:format]}"
puts "Files: #{info[:file_count]}"

Parameters:

  • path (String) —

    Path to CPIO file

Returns:

  • (Hash) —

    Archive information



114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
 
# File 'lib/omnizip/formats/cpio.rb', line 114

def info(path)
  open(path) do |cpio|
    entries = cpio.list

    {
      format: cpio.format_name,
      format_type: cpio.format,
      entry_count: entries.size,
      file_count: entries.count(&:file?),
      directory_count: entries.count(&:directory?),
      symlink_count: entries.count(&:symlink?),
      total_size: entries.sum(&:filesize),
    }
  end
end

.list(path) ⇒ Array<Entry>

List CPIO archive contents

Examples:

List archive contents

entries = Omnizip::Formats::Cpio.list('archive.cpio')
entries.each { |e| puts "#{e.name} (#{e.filesize} bytes)" }

Parameters:

  • path (String) —

    Path to CPIO file

Returns:

  • (Array<Entry>) —

    Archive entries



88
89
90
 
# File 'lib/omnizip/formats/cpio.rb', line 88

def list(path)
  open(path, &:list)
end

.open(path) {|reader| ... } ⇒ Reader

Open CPIO archive for reading

Examples:

Read CPIO archive

Omnizip::Formats::Cpio.open('archive.cpio') do |cpio|
  cpio.entries.each { |entry| puts entry.name }
end

Parameters:

  • path (String) —

    Path to CPIO file

Yields:

  • (reader) —

    Block for reading archive

Yield Parameters:

  • reader (Reader) —

    CPIO reader

Returns:



69
70
71
72
73
74
75
76
77
78
 
# File 'lib/omnizip/formats/cpio.rb', line 69

def open(path)
  reader = Reader.new(path)
  reader.open

  if block_given?
    yield reader
  else
    reader
  end
end

.register! ⇒ Object

Auto-register CPIO format when loaded



131
132
133
 
# File 'lib/omnizip/formats/cpio.rb', line 131

def register!
  FormatRegistry.register(".cpio", Reader)
end