zip - 解压缩 Zip 压缩的二进制字符串

Question

我在 Elixir 中有一个二进制字符串，它由压缩字节组成，我想放气并从中提取“真实数据”:

iex(93)> data
<<31, 139, 8, 0, 0, 0, 0, 0, 0, 0, 109, 80, 203, 110, 218, 64, 0, 76, 171, 70, 141, 68, 78, 105, 213, 67, 171, 74, 168, 7, 212, 86, 50, 172, 189, 94, 236, 69, 66, 173, 49, 40, 56, 96, 76, 130, 31, 196, 23, 226, 216, 11, 44, 216, 94, 227, 117, 13, 238, 199, 244, 208, 207, 234, 23, 244, 23, 122, 43, 137, 218, 91, 110, 243, 208, 204, 72, 83, 187, 56, 61, 59, 169, 255, 126, 121, 245, 227, 69, 237, 226, 125, 41, 117, 66, 150, 52, 105, 146, 241, 42, 92, 179, 230, 61, 99, 69, 148, 51, 26, 117, 196, 14, 122, 251, 170, 119, 164, 245, 254, 3, 175, 127, 188, 33, 15, 230, 167, 15, 53, 109, 58, 29, 27, 186, 102, 27, 214, 228, 243, 155, 167, 211, 210, 159, 231, 235, 162, 200, 120, 167, 213, 10, 210, 71, 165, 25, 198, 148, 164, 5, 111, 174, 24, 91, 197, 164, 121, 204, 181, 146, 32, 223, 146, 162, 21, 177, 125, 26, 179, 32, 106, 245, 255, 129, 47, 89, 16, 110, 131, 21, 153, 4, 9, 233, 62, 61, 208, 40, 73, 206, 41, 75, 117, 22, 145, 46, 106, 112, 30, 119, 197, 70, 193, 182, 36, 237, 106, 150, 173, 39, 192, 22, 151, 188, 93, 85, 75, 52, 2, 78, 110, 136, 90, 101, 17, 228, 43, 179, 126, 24, 109, 122, 217, 72, 231, 238, 140, 248, 83, 205, 229, 73, 79, 77, 101, 129, 162, 148, 135, 246, 88, 95, 32, 107, 39, 229, 153, 155, 219, 250, 118, 236, 196, 14, 104, 187, 150, 228, 91, 154, 194, 132, 188, 7, 29, 65, 25, 122, 201, 236, 90, 91, 78, 50, 49, 191, 180, 190, 29, 59, 146, 91, 213, 50, 23, 43, 92, 84, 36, 240, 124, 103, 98, 198, 90, 60, 47, 231, 133, 105, 175, 16, 173, 42, 67, 217, 5, 222, 149, 61, 208, 92, 115, 70, 215, 166, 158, 89, 17, 112, 239, 105, 168, 30, 134, 91, 60, 242, 6, 163, 18, 122, 202, 94, 42, 47, 157, 104, 176, 151, 199, 223, 5, 225, 154, 223, 82, 52, 104, 251, 150, 195, 131, 74, 223, 249, 169, 13, 54, 96, 108, 26, 195, 249, 46, 94, 192, 233, 58, 106, 252, 255, 203, 136, 186, 2, 148, 85, 36, 73, 176, 141, 17, 84, 177, 36, 42, 50, 132, 157, 119, 101, 146, 2, 44, 28, 82, 153, 142, 124, 111, 7, 5, 97, 64, 151, 192, 62, 32, 112, 195, 191, 254, 252, 101, 78, 79, 230, 207, 238, 78, 55, 103, 230, 227, 253, 125, 45, 127, 13, 48, 22, 177, 164, 96, 5, 41, 80, 145, 219, 0, 171, 16, 159, 159, 255, 5, 242, 139, 137, 38, 42, 2, 0, 0>>

我不确定如何解压缩这些数据。到目前为止，我已经:

• 浏览了 Official Elixir Docs
• 尝试使用 Erlang 的 :zip和 :zlib模块，但没有成功。他们都抛出错误:

iex(100)> :zlib.uncompress(data)        
** (ErlangError) erlang error: :data_error
    :zlib.call/3
    :zlib.inflate/2
    :zlib.uncompress/1

iex(101)> :zip.unzip data
{:error,
 {:EXIT,
  {{:badmatch,
    <<31, 139, 8, 0, 0, 0, 0, 0, 0, 0, 109, 80, 203, 110, 218, 64, 0, 76, 171, 70, 141, 68, 78, 105, 213, 67, 171, 74, 168, 7, 212, 86, 50, 172, 189, 94, 236, 69, 66, 173, 49, 40, 56, 96, 76, 130, ...>>},
   [{:zip, :binary_io, 2, [file: 'zip.erl', line: 1726]},
    {:zip, :get_end_of_central_dir, 3, [file: 'zip.erl', line: 1313]},
    {:zip, :get_central_dir, 3, [file: 'zip.erl', line: 1269]},
    {:zip, :do_unzip, 2, [file: 'zip.erl', line: 380]},
    {:zip, :unzip, 2, [file: 'zip.erl', line: 370]},
    {:erl_eval, :do_apply, 6, [file: 'erl_eval.erl', line: 670]},
    {:elixir, :erl_eval, 3, [file: 'src/elixir.erl', line: 215]},
    {:elixir, :eval_forms, 4, [file: 'src/elixir.erl', line: 203]}]}}}

我知道数据是正确的，我能够使用 JXG.Util.Unzip() 从 Javascript 中的相同字节中提取信息. 但是，我如何在 Elixir 中解压缩这些数据？

Answer 1

根据 file 命令，你的数据是 gzip 压缩数据，所以我尝试了 :zlib.gunzip 并且成功了:

iex(1)> data = <<31, 139, 8, 0, 0, 0, 0, 0, 0, 0, 109, 80, 203, 110, 218, 64, 0, 76, 171, 70, 141, 68, 78, 105, 213, 67, 171, 74, 168, 7, 212, 86, 50, 172, 189, 94, 236, 69, 66, 173, 49, 40, 56, 96, 76, 130, 31, 196, 23, 226, 216, 11, 44, 216, 94, 227, 117, 13, 238, 199, 244, 208, 207, 234, 23, 244, 23, 122, 43, 137, 218, 91, 110, 243, 208, 204, 72, 83, 187, 56, 61, 59, 169, 255, 126, 121, 245, 227, 69, 237, 226, 125, 41, 117, 66, 150, 52, 105, 146, 241, 42, 92, 179, 230, 61, 99, 69, 148, 51, 26, 117, 196, 14, 122, 251, 170, 119, 164, 245, 254, 3, 175, 127, 188, 33, 15, 230, 167, 15, 53, 109, 58, 29, 27, 186, 102, 27, 214, 228, 243, 155, 167, 211, 210, 159, 231, 235, 162, 200, 120, 167, 213, 10, 210, 71, 165, 25, 198, 148, 164, 5, 111, 174, 24, 91, 197, 164, 121, 204, 181, 146, 32, 223, 146, 162, 21, 177, 125, 26, 179, 32, 106, 245, 255, 129, 47, 89, 16, 110, 131, 21, 153, 4, 9, 233, 62, 61, 208, 40, 73, 206, 41, 75, 117, 22, 145, 46, 106, 112, 30, 119, 197, 70, 193, 182, 36, 237, 106, 150, 173, 39, 192, 22, 151, 188, 93, 85, 75, 52, 2, 78, 110, 136, 90, 101, 17, 228, 43, 179, 126, 24, 109, 122, 217, 72, 231, 238, 140, 248, 83, 205, 229, 73, 79, 77, 101, 129, 162, 148, 135, 246, 88, 95, 32, 107, 39, 229, 153, 155, 219, 250, 118, 236, 196, 14, 104, 187, 150, 228, 91, 154, 194, 132, 188, 7, 29, 65, 25, 122, 201, 236, 90, 91, 78, 50, 49, 191, 180, 190, 29, 59, 146, 91, 213, 50, 23, 43, 92, 84, 36, 240, 124, 103, 98, 198, 90, 60, 47, 231, 133, 105, 175, 16, 173, 42, 67, 217, 5, 222, 149, 61, 208, 92, 115, 70, 215, 166, 158, 89, 17, 112, 239, 105, 168, 30, 134, 91, 60, 242, 6, 163, 18, 122, 202, 94, 42, 47, 157, 104, 176, 151, 199, 223, 5, 225, 154, 223, 82, 52, 104, 251, 150, 195, 131, 74, 223, 249, 169, 13, 54, 96, 108, 26, 195, 249, 46, 94, 192, 233, 58, 106, 252, 255, 203, 136, 186, 2, 148, 85, 36, 73, 176, 141, 17, 84, 177, 36, 42, 50, 132, 157, 119, 101, 146, 2, 44, 28, 82, 153, 142, 124, 111, 7, 5, 97, 64, 151, 192, 62, 32, 112, 195, 191, 254, 252, 101, 78, 79, 230, 207, 238, 78, 55, 103, 230, 227, 253, 125, 45, 127, 13, 48, 22, 177, 164, 96, 5, 41, 80, 145, 219, 0, 171, 16, 159, 159, 255, 5, 242, 139, 137, 38, 42, 2, 0, 0>>
<<31, 139, 8, 0, 0, 0, 0, 0, 0, 0, 109, 80, 203, 110, 218, 64, 0, 76, 171, 70, 141, 68, 78, 105, 213, 67, 171, 74, 168, 7, 212, 86, 50, 172, 189, 94, 236, 69, 66, 173, 49, 40, 56, 96, 76, 130, 31, 196, 23, 226, ...>>
iex(2)> :zlib.gunzip(data)
<<11, 18, 5, 8, 0, 32, 232, 7, 74, 158, 4, 11, 18, 29, 118, 50, 58, 99, 111, 109, 46, 105, 109, 112, 115, 121, 99, 104, 111, 46, 98, 111, 111, 116, 100, 114, 111, 105, 100, 58, 49, 58, 53, 26, 19, 66, 111, 111, 116, 32, ...>>

来自docs .

gunzip(Data) -> Decompressed

Types:

Data = iodata()
Decompressed = binary()

Uncompress data (with gz headers and checksum).