7-Zip 9.32 alpha

[Igor Pavlov]

7-Zip 9.32 alpha was released.

This is a development version.
Don't use this alpha version to process important files and archives.
The code of this version contains big number of changes.
And probably there are some new BUGs.
If you use 7-Zip 9.32 alpha, check 7-Zip's forum periodically for updated information.

If you need more stable version, you can use previous versions: 7-Zip 9.25 alpha or 7-Zip 9.30 alpha.

7-Zip for 32-bit Windows:

http://dl.7-zip.org/7z932.exe
or
http://dl.7-zip.org/7z932.msi

7-Zip for 64-bit Windows x64:

http://dl.7-zip.org/7z932-x64.msi

7-Zip 9.32 alpha version is provided without source code.
Source code will be released in future beta version.

Please write here at forum about any new bugs.

What's new after 7-Zip 9.30 alpha:

• 7-Zip now can create multivolume SFX archives in 7z format.
• ZIP, NSIS, HFS, AR support was improved.
• 7-Zip now supports files larger than 4 GiB in ISO archives
• Improved compression ratio in 7z format with maximum or ultra level for
  executable files (EXE and DLL) that are larger than 16 MB (improved BCJ2 filter).
• Improved support for file pathnames longer than 260 characters.
• CRC and SHA checksum calculation for files can be called via Explorer's context menu.
• 7-Zip File Manager now also takes into account the numbers in filenames for sorting order.
• 7-Zip File Manager now can use RAM buffers instead of temp files to open
  nested archives, if temp file is smaller than 1/4 of RAM size.
• 7-Zip File Manager can open files in "Parser" mode via "Open Archive > #" context
  menu command. It shows the list of archives inside file.
• Command line version:
  • new -t# switch to open file in "Parser" mode and show the list of archives inside file.
  • new -stx{Type} switch to exclude archive type from using.
  • -scs switch now supports UTF-16 encoding.
  • now it shows time and memory usage statistics at the end of execution.
• The BUGs were fixed:
  • 7-Zip 9.30 and early versions created ZIP archives with minor errors
    in extra field of headers for directory items, if AES (WinZip-AES) encryption was used.
  • 7-Zip could work incorrectly in decompression of more than one
    multi-volume archive in one command.
  • 7-Zip 9.24 alpha - 9.30 alpha versions could not extract ZIP archives
    encrypted with PKWARE-AES method.
• Minimum supported system now is Windows 2000. 7-Zip does not work on Windows 95/98/ME.
• New localization: Irish.

Some BUGs of 7-Zip 9.31 alpha were fixed:
- 7-Zip could not unpack some RAR archives
- 7-Zip File Manager could work incorrectly for unpacking from solid archives,
if archive was open in 7-Zip File Manager. Also 7-Zip File Manager could leave
some unpacked files in TEMP folder of Windows.
So look your TEMP folder and remove folders that have "7z" prefix in name.

[Love4Boobies]

Up to and including 2010, you've released one or more stable versions of 7-Zip every year. However, it's 2014 and there hasn't been a stable release since. Is it because you don't really have time for 7-Zip's development and it's now on the back burner?

[ITRedRat]

When and where released new stable version for all? Please.

[Carlos Sang]

Unable to open these files. Able to do so with WinRAR

Part1: http://www11.zippyshare.com/v/73279223/file.html
Part2: http://www11.zippyshare.com/v/10079761/file.html

[Stefan M.]

I found a new bug in 7.32alpha:

If "Flat View" is selected/active, and i Doubleclick one Folder (I know, this does not make sense), then 7zip crashes - an error-message should be displayed instead or the view should automatically change..

[Stefan M.]

I found a new bug in 7.32alpha:

If "Flat View" is selected/active, and i Doubleclick one Folder (I know, this does not make sense), then 7zip crashes - an error-message should be displayed instead or the view should automatically change..

[Tomasz Wasiak]

Hello,

I would like to kindly ask if newer than 9.22 standalone (7za) version is available?
Could you provide standalone 9.32 version?

Thank you in advance

[Eugene Kotlyarov]

This version cannot open zip archives with archive comment.
Also could you add archive comment support to 7-zip file manager

[Igor Pavlov]

Please attach small example of such zip.

[Eugene Kotlyarov]

Here is test archive, it works ok with 7-zip 9.22 and Winrar

[Igor Pavlov]

There is error in extra field for test.txt in that archive.
I'll fix 7-Zip code. So it will open that archive.

[Jason Liu]

Thanks Igor,

MS installer file, such as KBxxxx, it's cab sfx.
7-zip 9.32 extractor just fine, but still shows there're something wrong. i guess the same problem as EXE-stub, NSIS-archive.

[Oliver Jia]

thanks Igor!
Installed and the x64 version and it appears to be working great.

[Shell]

Igor, thank you for the new version. I have got a couple of questions about the new features.

1. What improves the compression for big executables? Is it an optimization of BCJ2 code or a change in its streams' compression options? Does that change affect the compatibility?

2. What features use Win9x-incompatible code? Will 7-Zip 9.32 run on Windows NT 4.x? (By the way, OS version field in the EXE files is still 4.0).

[Igor Pavlov]

1. It keeps compatibility.
   BCJ2 now converts CALL branches of range +-64MB.
   Previous version was only +- 16 MB.
   .text section of executable must be larger than 16 MB to see any improvement. There are no too many such executables. Maybe Chrome is largest executable.
   What another big executables with big .text section do you know?
   You can check the size of .text section with 7-Zip.

2. Previous 32-bit versions of 7-Zip worked so:

if (it_is_NT)
CallUnicodeFunction();
else
CallNonUnicodeFunction();

now it works so:
CallUnicodeFunction();

So executables now are smaller.

7-Zip 9.32 probably can work on NT 4.0 too. But I didn't test it. I even didn't test on win2000.

[Shell]

Thank you for the quick reply.

The biggest executables I know belong to Skype and MS Office. I don't remember Chrome's size (by the way, it loves keeping several 7z archives without compression in the user's profile). I'll test Excel and Groove 2010 with 7-Zip 9.30 and 9.32 and post the results here.

According to Unicode transition, 7-Zip may be compatible with Win9x if the Unicode support layer is installed. I'll check that, too.

Update. 7-Zip 9.32 installs on Windows 95/98/ME providing that msvcrt.dll and Windows Installer 2.0 (for the MSI version) are installed. However, it does not work: 7z.exe requires psapi.dll, and the File manager requires LsaOpenPolicy() from advapi32.dll. Shell extensions do not work either. 7-Zip 9.31 works perfectly on WinME, and 7z.exe works even on Windows 95 OSR2 (the File Manager requires a newer version of shell32.dll).

Update 2. Windows NT 4.0 Workstation, on the other hand, lacks Toolhelp API, so even 7-Zip 9.22 refuses to start the File Manager (version 9.20 does work). However, 7-Zip 9.31 Console works fine even without service packs. 7-Zip 9.32 shell extensions (including 7zG.exe) work under SP6a (I haven't checked that on previous SPs).

Windows 2000 is indeed enough for 7-Zip 9.32. Interestingly, copying psapi.dll from Windows 2000 makes 7-Zip 9.32 Console work on NT 4.0 SP6a (but not on ME).

[Shell]

I have tested 20 files: Google Chrome 30/31 DLLs, MS Office 2010/2013 x86 executables and DLLs, and Skype 6.x executables, each features a .text section from 16 to 44.5 MiB. In addition, I have tried an Excel 2007 converter from the Compatibility Pack, which has a 13-MiB .text section. I have used 7-Zip 9.30 and 9.31 (9.32 has the same BCJ2 code) with the following settings:
7z a -mx9 -ms- -mf=bcj2
As expected, the "tiny" excelcnv.exe has shown no improvement between those versions. The bigger Chrome's and Office's files have all benefited from the new code, ranging from a difference in several KiBs to a gain of over 17%. Skype has turned to be poor-compressible with the gain from -0.002% (6.11) to +0.001% (6.7).

I have also discovered a strange thing: LZMA2 may compress better having two threads instead of one. I understand why splitting the data into chunks degrades the compression, but how can multithreading increase it?

[Igor Pavlov]

LZMA and LZMA2 doesn't use chunks for 2 threads in -mx5 ... -mx9 modes.
The code of match finder in multi-threading mode is not equal for 100% to single-threading code. So there is very small difference in results.

[Ilya S]

.text section of executable must be larger than 16 MB to see any improvement.
There are no too many such executables. Maybe Chrome is largest executable.
What another big executables with big .text section do you know?
There are:
- 26MB .text size in clang.exe/clang++.exe from android NDK
- 26MB in Prime95.exe
- 20MB in Skype.exe
- 19MB in chrome.dll
- 22MB in chrome_child.dll
- 20MB in FSharp.Compiler.ni.dll
Not many, for sure, yet they are.

[Igor Pavlov]

Jason Liu:

These CAB_SFX from Microsoft is more difficult case.
They contain some non-zero data chunks (from 4 to 16 bytes)
between CAB archive and certificate.
7-Zip doesn't like it.
I don't know why do they write that additional data to CAB-SFX. Maybe it's garbage data. Or they can store some checksums there?

[Jason Liu]

Thanks for explain this clearly.
Mmm, that's not big deal, those .exe can rename .zip to extractor.

[Speciesx]

I can't open some zip files like this.

[Igor Pavlov]

Speciesx:
I'll fix it. thanks!

It has ms dos timestamp = 0 for files.

[windux]

Dear Igor,
thanks a lot for your great software!
I use 7za.exe in scripts. Last version I know is 2 years old (9.22).
Would it be possible to provide 7za with new alphas?

[Anonymous]

thank