7-Zip

7-Zip 21.07

21.07 2021-12-26
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- 7-Zip now can extract VHDX disk images (Microsoft Hyper-V Virtual Hard Disk v2 format).
- New switches: -spm and -im!{file_path} to exclude directories from processing
for specified paths that don't contain path separator character at the end of path.
- In the "Add to Archive" window, now it is allowed to use -m prefix for "Parameters"
field as in command line: -mparam.
- The sorting order of files in archives was slightly changed to be more consistent
for cases where the name of some directory is the same as the prefix part of the name
of another directory or file.
- TAR archives created by 7-Zip now are more consistent with archives created by GNU TAR program.

What's new after 7-Zip 21.04 beta:​

  • The window "Add to Archive" now allows to set a limit on memory usage (RAM) that will be used for compressing.
  • New switch -mmemuse={N}g / -mmemuse=p{N} to set a limit on memory usage (RAM) for compressing and decompressing.
  • Bug in versions 21.00-21.05 was fixed:
    7-Zip didn't set attributes of directories during archive extracting.
  • Some bugs were fixed.

What's new after 7-Zip 21.04 beta:​

  • The window "Add to Archive" now allows to set a limit on memory usage (RAM) that will be used for compressing.
  • New switch -mmemuse={N}g / -mmemuse=p{N} to set a limit on memory usage (RAM) for compressing and decompressing.
  • Some bugs were fixed.

What's new after 7-Zip 21.03 beta:​

  • 7-Zip now reduces the number of working CPU threads for compression, if RAM size is not enough for compression with big LZMA2 dictionary.
  • 7-Zip now can create and check "file.sha256" text files that contain the list of file names and SHA-256 checksums in format compatible with sha256sum program. 7-Zip can work with such checksum files as with archives, but these files don't contain real file data.
    The context menu commands to create and test "sha256" files:
Code:
7-Zip  /  CRC SHA  /  SHA-256 -> file.sha256
7-Zip  /  CRC SHA  /  Test Archive : Checksum


The commands for command line version:
Code:
7z a -thash file.sha256 *.txt
7z t -thash file.sha256
7z t -thash -shd. file.sha256


  • New -shd{dir_path} switch to set the directory that is used to check files referenced by "file.sha256" file for "Test" operation. If -shd{dir_path} is not specified, 7-Zip uses the directory where "file.sha256" is stored.
  • New -xtd switch to exclude directory items from processing.

Note:
7-Zip's "Add to Archive" window now shows default options with asterisk character:
Code:
Compression method: * LZMA
Dictionary size: * 32 MB


So there are some changes in code that selects default settings for each option. And 7-Zip tries to reduce the number of threads, if it can help to fit in RAM Size, if big dictionary size is specified.
Note also, that if you select default option with asterisk, that selected value will be not transferred to 7-zip compression engine. But 7-zip compression engine knows about default options, and it must use same values as shown to user in "Add to Archive" window.
21.03 beta 2021-07-20
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- The maximum dictionary size for LZMA/LZMA2 compressing was increased to 4 GB (3840 MiB).
- Minor speed optimizations in LZMA/LZMA2 compressing.
21.01 alpha 2021-03-09
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- The command line version of 7-Zip for Linux was released.
- The improvements for speed of ARM64 version using hardware CPU instructions
for AES, CRC-32, SHA-1 and SHA-256.
- The bug in versions 18.02 - 21.00 was fixed:
7-Zip could not correctly extract some ZIP archives created with xz compression method.
- Some bugs were fixed.
21.00 alpha 2021-01-19
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- Some internal changes in code.
- Some bugs were fixed.
- New localizations: Tajik, Uzbek (Cyrillic)
20.02 alpha 2020-08-08
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- The default number of LZMA2 chunks per solid block in 7z archive was increased to 64.
It allows to increase the compression speed for big 7z archives, if there is a big number
of CPU cores and threads.
- The speed of PPMd compressing/decompressing was increased for 7z/ZIP/RAR archives.
- The new -ssp switch. If the switch -ssp is specified, 7-Zip doesn't allow the system
to modify "Last Access Time" property of source files for archiving and hashing operations.
- Some bugs were fixed.
- New localization: Swahili.
20.00 alpha 2020-02-06
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- 7-Zip now supports new optional match finders for LZMA/LZMA2 compression: bt5 and hc5,
that can work faster than bt4 and hc4 match finders for the data with big redundancy.
- The compression ratio was improved for Fast and Fastest compression levels with the
following default settings:
- Fastest level (-mx1) : hc5 match finder with 256 KB dictionary.
- Fast level (-mx3) : hc5 match finder with 4 MB dictionary.
- Minor speed optimizations in multithreaded LZMA/LZMA2 compression for Normal/Maximum/Ultra
compression levels.
- bzip2 decoding code was updated to support bzip2 archives, created by lbzip2 program.
- Some bugs were fixed.
- New localization: Turkmen.
19.02 alpha 2019-09-05
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- 7-Zip now can unpack files encoded with Base64 encoding (b64 filename extension).
- 7-Zip now can use new x86/x64 hardware instructions for SHA-1 and SHA-256, supported
by AMD Ryzen and latest Intel CPUs: Ice Lake and Goldmont.
It increases
- the speed of SHA-1/SHA-256 hash value calculation,
- the speed of encryption/decryption in zip AES,
- the speed of key derivation for encryption/decryption in 7z/zip/rar archives.
- The speed of zip AES encryption and 7z/zip/rar AES decryption was increased with
the following improvements:
- 7-Zip now can use new x86/x64 VAES (AVX Vector AES) instructions, supported by
Intel Ice Lake CPU.
- The existing code of x86/x64 AES-NI was improved also.
- There is 2% speed optimization in 7-Zip benchmark's decompression.
- Some bugs were fixed.
Oben Unten