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Questions tagged [7zip]

"7z" or "7-Zip" may refer either to the open-source 7z compression container format or to the file name of the executable program of the same name that is the flagship implementation of the compression format. Both are GPL-licensed and under active development.

"7z" or "7-Zip" may refer either to the open-source 7z compression container format or to the file name of the executable program of the same name that is the flagship implementation of the compression format. Both are GPL-licensed and under active development.

The 7z format is a compressed archive file format that supports several different data compression, encryption and pre-processing algorithms. The LZMA SDK 4.62 was placed in the public domain in December 2008. The latest stable version of 7-Zip and LZMA SDK is version 18.05. The MIME type of 7z is application/x-7z-compressed.

The 7-Zip program is an open source file archiver. 7-Zip operates with the 7z archive format, but can read and write several other archive formats. The program can be used from a command line interface, graphical user interface, or with Microsoft Windows shell integration. 7-Zip's development began in 1999, and it is actively developed by Igor Pavlov. It is related to a cross-platform port, p7zip. 7-Zip is free software distributed under the GNU Lesser General Public License (LGPL). It was the winner of the SourceForge.net 2007 community choice awards for "Technical Design" and for "Best Project".

7z has an open architecture, so it can support any new compression methods. Now the following methods are integrated to 7z:

  1. LZMA: Improved and optimized version of LZ77 algorithm
  2. LZMA2: Improved version of LZMA
  3. PPMD: Dmitry Shkarin's PPMdH with small changes
  4. BCJ: Converter for 32-bit x86 executables
  5. BCJ2: Converter for 32-bit x86 executables
  6. BZip2: Standard BWT algorithm
  7. Deflate: Standard LZ77-based algorithm
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How key_derivation and key_verification functions are implemented of a 7-zip archive's encryption mechanism?

I am curious about how password recovery works for password protected files. And I want to know the exact flow of the 7-zip encryption mechanism. 7-zip uses AES-256 encryption algorithm in CBC mode, to encrypt files or a folder. The key is generated…
Gopal
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Is it possible to resume 7zip compression?

My application regularly upload large files. Regardless of their size, all files are compressed before uploaded to server. Part of this project requirements is to resume nicely after crash/power failure, so right now compression is done this…
TheDude
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extract 7zip in C# code

I need use 7zip in C#. Without console, just with 7zSharp.dll ? + I find some data here http://7zsharp.codeplex.com/releases/view/10305 , but I don't know how to use it( - I could create .bat(.cmd) file, but I need throught dll file) Exactly: I…
koder_mooder
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Archiving thousands of files and 7zip limitations

My application requires that a task is run everyday in which 100,000+ PDF (~ 50kb each) files need to be zipped. Currently, I'm using 7-zip and calling 7za.exe (the command line tool with 7-zip) to zip each file (files are located in many different…
Omar
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Why does 7zip Ignore my InstallPath when making a SFX installer?

Currently, I am making a SFX with 7zip using the following config: ;!@Install@!UTF-8! InstallPath="C:\\test" GUIMode="2" RunProgram="7z465.exe" ;!@InstallEnd@! I then package 7z465.exe into Setup.7z, and then call the following line in a batch…
Ben
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Can Delphi JCL 7zCompression used to compress/decompress in-memory stream without file operations?

I had used TJcl7zCompressArchive / TJcl7zDecompressArchive to do Archive operation before. Now I would like to compress / decompress in-memory streams directly without file operation. However, when seeing the examples from JCL demos searching in…
Justmade
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Java 7zip compression is too big

I have a Java program which searches for a folder with the date of yesterday and compresses it to a 7zip file and deletes it at the end. Now I have noticed that the generated 7zip archive files by my program are way too big. When I use a program…
Mad Scientist
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LzmaLib: compress / decompress buffer in C

I'm trying to use LzmaLib's LzmaCompress() and LzmaDecompress() with buffers, adapting the examples provided here. I'm testing with a ~3MB buffer and the compression function seems to work fine (produces a ~1.2MB compressed buffer), but when I try…
karliwson
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recreate excel .xlsx file from unzipped xml folder

I'm trying to convert a folder of xml that was created by unzipping an excel file back into an excel .xlsx. But I get the error The workbook cannot be opened or repaired by Microsoft Excel because it is corrupt A minimal reproducible example to…
dww
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Sample C# .net code for zipping a file using 7zip

I have installed 7-zip 4.65 on my machine at C:\Program files. I want to use it in C# code to zip a file. The file name will be provided by the user dynamically. Can any one please provide a sample code on how to use 7zip in C# code?
user386647
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7zip ISO extraction

I have been trying to extract an ISO image through 7zip and WinRar. Here is the command line that I used: 7z x -y "%Isocontents%\ISO.iso" -o%Newfolder% WinRar.exe x -y -ow "%Isocontents%\ISO.iso" "%Newfolder%" Entire project uses generic batch /…
minu
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Catch an error inside a batch file (7-zip)

I have a batch file in which I execute the following line to list the contents of an archive: "\Program Files\7-Zip\7z.exe" l "\Backup Google Docs.7z" The archive is intentionally corrupted. cmd.exe displays this: How can I catch this error in my…
GG.
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How do I know if 7zip used AES256?

I originally was using WinZip15 to create .ZIP files with AES256 which we later package into .EXE files using WinZip's self extracting tool (since we can't be sure the people we are giving the archives to will have a zip utility that can handle…
Jai
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Command line 7zip issues when encrypting headers

I'm creating an zip file using 7zip from the command line during my build process. using a command like this: 7z.exe a -pPassword "..\sot.zip" . This command works correctly and I'm able to see an encrypted file as expected. Now when I add the…
Hucker
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How to pipe 7z output to 7z

I'm writing a bash script which should extract content of one 7z file and compress that extracted content to a new 7z file. The command I've tried is 7z x -o/tmp/ "/home/file1.7z" | 7z a -t7z "/home/file2.7z"
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