xar unarchiver (.xar, .pkg, .xip)
implement initial decompression logic
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czar.cr
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czar.cr
···
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#!/usr/bin/env crystal
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require "binary_parser"
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require "compress/zlib"
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require "compress/gzip"
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require "xml"
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require "./sliceio"
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require "./bzip2"
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def perror(msg : String)
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STDERR.write Slice.new (msg + "\n").to_unsafe, (msg + "\n").size
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STDERR.write Slice.new((msg + "\n").to_unsafe, (msg + "\n").size)
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exit 1
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end
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···
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file.size = (xml_value(entity, "size").first rescue 0).to_u64
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data = xml_select(entity, "data")
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unless data.size < 1
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unless data.empty?
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xar_decode_data data.first, file.data
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end
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ea = xml_select(entity, "ea")
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unless ea.size < 1
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unless ea.empty?
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xar_decode_ea ea.first, file.ea
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end
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files = [file]
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children = xml_select(entity, "file")
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if children.size > 0
···
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perror "no filename given" if ARGV.size == 0
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File.open ARGV.first, "r" do |file|
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File.open(ARGV.first, "r") do |file|
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header = XARHeader.new
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header.load file
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···
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toc_data = Bytes.new header.length_uncompressed
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file.seek header.header_size
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Compress::Zlib::Reader.open file do |zfile|
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zfile.read toc_data
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end
···
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tocs = xml_select(xar_obj.first, "toc")
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perror "empty TOC" if tocs.empty?
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toc = tocs.first
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toc = tocs.first
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puts "reading TOC"
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xar = XAR.new
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xar = XAR.new
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elem = xml_select(toc, "checksum").first
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xar.checksum.style = XARChecksumAlgo.parse elem["style"]
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xar.checksum.size = xml_value(elem, "size").first.to_u64
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xar.checksum.offset = xml_value(elem, "offset").first.to_u64
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puts "TOC is checksummed as #{xar.checksum.style}, #{xar.checksum.size} bytes at offset #{xar.checksum.offset}"
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xml_select(toc, "file").each do |entity|
···
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end
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puts "contains #{xar.files.select { |e| e.type == XARFileType::FILE }.size} files across #{xar.files.select { |e| e.type == XARFileType::DIRECTORY }.size} directories"
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puts xar.files.map{ |e| "#{e.path}#{e.name}" }.join " "
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puts xar.files.map{ |e| "#{e.path}#{e.name}" }.join " "
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# Unarchive files
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xar.files.each do |xarfile|
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next if xarfile.type == XARFileType::DIRECTORY
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output_path = File.join("#{ARGV.first}.extracted", xarfile.path, xarfile.name)
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Dir.mkdir_p(File.dirname(output_path)) unless File.exists?(File.dirname(output_path))
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# Log file metadata
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puts "Processing file: #{output_path}"
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puts " Offset: #{xarfile.data.offset}"
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puts " Size: #{xarfile.data.size}"
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puts " Encoding: #{xarfile.data.encoding}"
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# Seek to the correct offset in the archive file
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file.seek header.header_size.to_u64 + header.length_compressed + xarfile.data.offset
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# Read the compressed data
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compressed_data = Bytes.new(xarfile.data.size)
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file.read(compressed_data)
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# Decompress the data if necessary
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decompressed_data = case xarfile.data.encoding
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when XARFileEncoding::GZIP
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Compress::Gzip::Reader.new(SliceIO.new(compressed_data)).getb_to_end
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when XARFileEncoding::BZIP2
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Bzip2::Reader.new(SliceIO.new(compressed_data)).getb_to_end
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else
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compressed_data
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end
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# Write the decompressed data to the output file
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begin
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File.write(output_path, decompressed_data)
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puts "Extracted: #{output_path}"
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rescue e
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perror "Error writing file #{output_path}: #{e}"
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end
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end
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end