228 lines
7.7 KiB
Elixir
228 lines
7.7 KiB
Elixir
defmodule Dotzip do
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@moduledoc """
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Elixir Implementation of ZIP File Format. https://pkware.cachefly.net/webdocs/APPNOTE/APPNOTE-6.3.3.TXT
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"""
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def decode(file) do
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{:ok, local, rest} = Dotzip.LocalFileHeader.decode(file)
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{:ok, central, r} = Dotzip.CentralDirectoryHeader.decode(rest)
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{:ok, e, rr} = Dotzip.EndCentralDirectory.decode(r)
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{local, central, e, rr}
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end
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end
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defmodule Dotzip.LocalFileHeader do
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defp signature(<< 0x50, 0x4b, 0x03, 0x04, rest::bitstring >>) do
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{:ok, %{}, rest}
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end
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defp version({:ok, data, << version::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :version, version), rest}
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end
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defp purpose_flag({:ok, data, << purpose_flag::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :purpose_flag, purpose_flag), rest}
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end
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defp compression_method({:ok, data, << compression_method::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :compression_method, compression_method), rest}
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end
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defp last_modification_time({:ok, data, << last_modification::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :last_modification_time, last_modification), rest}
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end
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defp last_modification_date({:ok, data, << last_modification_date::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :last_modification_date, last_modification_date), rest}
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end
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defp crc32({:ok, data, << crc32::binary-size(4), rest::bitstring >>}) do
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{:ok, Map.put(data, :crc32, crc32), rest}
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end
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defp compressed_size({:ok, data, << compressed_size::little-size(32), rest::bitstring >>}) do
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{:ok, Map.put(data, :compressed_size, compressed_size), rest}
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end
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defp uncompressed_size({:ok, data, << uncompressed_size::little-size(32), rest::bitstring >>}) do
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{:ok, Map.put(data, :uncompressed_size, uncompressed_size), rest}
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end
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defp file_name_length({:ok, data, << file_name_length::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :file_name_length, file_name_length), rest }
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end
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defp extra_field_length({:ok, data, << extra_field_length::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :extra_field_length, extra_field_length), rest}
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end
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defp file_name({:ok, data, rest}) do
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%{ :file_name_length => file_name_length } = data
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<<file_name::binary-size(file_name_length), r::bitstring>> = rest
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{:ok, Map.put(data, :file_name, file_name), r}
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end
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defp extra_field({:ok, data, rest}) do
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%{ :extra_field_length => extra_field_length } = data
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<<extra_field::binary-size(extra_field_length), r::bitstring>> = rest
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{:ok, Map.put(data, :extra_field, extra_field), r}
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end
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defp content({:ok, data, rest}) do
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%{ :compressed_size => compressed_size } = data
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<<content::binary-size(compressed_size), r::bitstring>> = rest
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{:ok, Map.put(data, :content, content), r}
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end
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def decode(file) do
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{:ok, local_file_header, rest} = signature(file)
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|> version()
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|> purpose_flag()
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|> compression_method()
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|> last_modification_time()
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|> last_modification_date()
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|> crc32()
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|> compressed_size()
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|> uncompressed_size()
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|> file_name_length()
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|> extra_field_length()
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|> file_name()
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|> extra_field()
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|> content()
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end
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end
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defmodule Dotzip.CentralDirectoryHeader do
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defp signature(<< 0x50, 0x4b, 0x01, 0x02, rest::bitstring >>) do
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{:ok, %{}, rest}
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end
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defp version_made({:ok, data, << version::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :version_made, version), rest}
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end
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defp version_needed({:ok, data, << version::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :version_needed, version), rest}
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end
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defp purpose_flag({:ok, data, << purpose_flag::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :purpose_flag, purpose_flag), rest}
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end
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defp compression_method({:ok, data, << compression_method::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :compression_method, compression_method), rest}
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end
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defp last_modification_time({:ok, data, << last_modification::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :last_modification_time, last_modification), rest}
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end
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defp last_modification_date({:ok, data, << last_modification_date::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :last_modification_date, last_modification_date), rest}
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end
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defp crc32({:ok, data, << crc32::binary-size(4), rest::bitstring >>}) do
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{:ok, Map.put(data, :crc32, crc32), rest}
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end
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defp compressed_size({:ok, data, << compressed_size::little-size(32), rest::bitstring >>}) do
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{:ok, Map.put(data, :compressed_size, compressed_size), rest}
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end
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defp uncompressed_size({:ok, data, << uncompressed_size::little-size(32), rest::bitstring >>}) do
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{:ok, Map.put(data, :uncompressed_size, uncompressed_size), rest}
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end
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defp file_name_length({:ok, data, << file_name_length::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :file_name_length, file_name_length), rest }
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end
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defp extra_field_length({:ok, data, << extra_field_length::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :extra_field_length, extra_field_length), rest}
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end
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defp file_comment_length({:ok, data, << file_comment_length::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :file_comment_length, file_comment_length), rest}
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end
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defp disk_number_start({:ok, data, << disk_number_start::little-size(16), rest::bitstring >>}) do
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{:ok, Map.put(data, :disk_number_start, disk_number_start), rest}
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end
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defp internal_file_attributes({:ok, data, << internal_file_attributes::binary-size(2), rest::bitstring >>}) do
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{:ok, Map.put(data, :internal_file_attributes, internal_file_attributes), rest}
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end
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defp external_file_attributes({:ok, data, << external_file_attributes::binary-size(4), rest::bitstring >>}) do
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{:ok, Map.put(data, :external_file_attributes, external_file_attributes), rest}
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end
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defp relative_offset({:ok, data, << relative_offset::little-size(32), rest::bitstring >>}) do
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{:ok, Map.put(data, :relative_offset, relative_offset), rest}
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end
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defp file_name({:ok, data, rest}) do
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%{ :file_name_length => file_name_length } = data
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<<file_name::binary-size(file_name_length), r::bitstring>> = rest
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{:ok, Map.put(data, :file_name, file_name), r}
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end
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defp extra_field({:ok, data, rest}) do
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%{ :extra_field_length => extra_field_length } = data
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<<extra_field::binary-size(extra_field_length), r::bitstring>> = rest
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{:ok, Map.put(data, :extra_field, extra_field), r}
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end
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defp file_comment({:ok, data, rest}) do
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%{ :file_comment_length => file_comment_length } = data
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<<file_comment::binary-size(file_comment_length), r::bitstring>> = rest
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{:ok, Map.put(data, :file_comment, file_comment), r}
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end
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def decode(file) do
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{:ok, central_directory_header, rest} = signature(file)
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|> version_made()
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|> version_needed()
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|> purpose_flag()
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|> compression_method()
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|> last_modification_time()
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|> last_modification_date()
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|> crc32()
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|> compressed_size()
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|> uncompressed_size()
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|> file_name_length()
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|> extra_field_length()
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|> file_comment_length()
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|> disk_number_start()
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|> internal_file_attributes()
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|> external_file_attributes()
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|> relative_offset()
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|> file_name()
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|> extra_field()
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|> file_comment()
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end
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end
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defmodule Dotzip.EndCentralDirectory do
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defp signature(<< 0x50, 0x4b, 0x05, 0x06, rest::bitstring >>) do
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{:ok, %{}, rest}
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end
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defp number_disk({:ok, data, << number_disk::little-size(32), rest::bitstring >>}) do
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{:ok, Map.put(data, :number_disk, number_disk), rest}
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end
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def decode(file) do
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{:ok, end_central_directory, rest} = signature(file)
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|> number_disk()
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end
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end
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