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Printing info about ZIP archives

You can print information about a ZIP archive or a file within a ZIP archive to the terminal (or any IO object) with the three-argument show method, specifically show(::IO, ::MIME"text/plain", file_or_archive). Note that this method is automatically called by the REPL to display such an object if it is the return value of the most recent statement. The format of the information displayed for each file is similar to the short format produced by ZipInfo.

In general, the output has the following format:

TTTT UUUUUUUU ZZZ LLL CCCCCCCC XXXX dd-mmm-yy hh:mm:ss 0xSSSSSSSS NAME

The definitions of these fields are, in order:

  • TTTT: Either the string "file" or "dir ", signifying what kind of entry it is;
  • UUUUUUUU: The uncompressed size of the file in bytes;
  • ZZZ: Either the string "z64" or "---", signifying that the Local File Header uses the Zip64 format;
  • LLL: Either the string "lhx" or "---", signifying that a Data Descriptor is used;
  • CCCCCCCC: The compressed size of the file in bytes;
  • XXXX: The compression method used to compress the data;
  • dd-mmm-yy hh:mm:ss: The creation date and time of the file;
  • 0xSSSSSSSS: The CRC-32 checksum of the compressed data as a hexadecimal number;
  • NAME: The name of the entry in the Local File Header.

If called on an archive source, info about all of the archived entities read from the source so far is printed in archive order, along with status information about how much has been read from the archive so far, whether or not the EOF has been reached, and statistics about the number and size of the entries.

The first call to show in this example reports nothing has been read yet:

using ZipStreams

buffer = IOBuffer();
zipsink(buffer) do sink
    write_file(sink, "hello.txt", "Hello, Julia!");
    write_file(sink, "subdir/goodbye.txt", "Goodbye, Julia!"; compression=:store, make_path=true);
end

seekstart(buffer);
source = zipsource(buffer)

# output

ZIP archive source stream data after reading 0 B, number of entries: 0

After reading all of the data in the archive using vialidate, the next thing that is shown is information about the entities read:

@assert is_valid!(source)
source

# output

ZIP archive source stream data after reading 348 B (EOF reached), number of entries: 3
file       13 --- ---       15 defl 02-Nov-22 00:58:36 0xb2284bb4 hello.txt
dir         0 --- ---        0 stor 02-Nov-22 00:58:36 0x00000000 subdir/
file       15 --- ---       15 stor 02-Nov-22 00:58:36 0xb24bab9f subdir/goodbye.txt
2 files, 28 B uncompressed, 30 B compressed