7ZIP CRC32 Signatures, Compression Ratio, and Packed Size missing

  • I have noticed that 7ZIP files lack a CRC32 signature in the compressed archive file. I would think that CRC32 would provide some guarantee that the files were intact.

    Also, I have noticed that the compression ratio as well as the Packed Size is missing also.

    All three headers only show a “?”. Why is this so?

  • conexware


    Currently, PowerArchvier does not display CRC or packed size info for 7zip archives. In general, when archive is solid (which means that all files are treated as one big file) you do not have single file info. 7zip still stores CRC info but no packed info, so you wont see compression ratio either.

    We will implement support for displaying full info in non-solid archives and crc info in solid archives when we update our 7zip support for 9.5.

    CRC signature is still checked when archive is being extracted by 7zip.dll, so you should get an error message if file is corrupted.


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