Linux – Extract 7z files with standard linux tools

As far as I can tell, 7-zip doesn't have a command that does what you're looking for. Here's a Windows batch file script which I think will do what you want. It should be run from the command line so you can supply a path to the root of the folder tree to be processed.

File unzipper.bat

@echo off
setlocal
if "%1"=="" goto Usage

call :Get7zCmd
:: Recurse folder passed in as paramater
for /r %1 %%Z in (*.zip) do (
    echo ====
    rem Change to the directory of zip file
    cd /d "%%~dpZ"
    rem Extract all files to current directory
    echo %_7zCmd% e "%%~nxZ" -y
    rem Delete the zip file
    echo del "%%~nxZ"
)
goto End

:Usage
echo.
echo Parses through folder structure starting at the specified path, finding
echo and extracting the contents of all zip files found, and then deletes
echo the zip file.
echo.
echo Usage:
echo     %~n0 root-directory-path
echo.
echo     For example:
echo.
echo %~n0 "D:\some folder"

:End
goto :EOF

:: ==========================
:: Subroutine Get7zCmd
:: Determines the full path to 7-zip command-line executable from the Windows
:: Registry and sets the variable "_7zCmd" to the result.
:Get7zCmd
set Reg.Key=HKLM\Software\Microsoft\Windows\CurrentVersion\App Paths\7zFM.exe
set Reg.Val=Path
for /F "Tokens=2*" %%A in ('Reg Query "%Reg.Key%" /v "%Reg.Val%" ^| find /I "%Reg.Val%"') do call set PathDirectory=%%B
set _7zCmd="%PathDirectory%%\7z.exe"
exit /b 0

Since as a whole what the script does is fairly radical and potentially destructive because it might extract large numbers of file and delete many zip files afterward, I've disabled the commands on lines 12 and 14 which would do those things by prefixing them with echo. This make them just print out what they would have done if the echo wasn't there. That way you can test the script first without doing any damage to your file system should there be some sort of unexpected problem.

To modify the script actually perform these actions, you'll need to remove the echo on each of the two lines. Standard disclaimer of any liability applies, of course.

There are a large variety of compression formats and methods available, some don't compress at all and are designed to store a number of files in one archive, and other newer experimental compressors (PAQ based) are designed to compress as aggressively as possible, regardless of the time it takes to perform said operation.

You need to evaluate the features you require from your compression method choice, and also consider the context in which it will be used.

Different features and considerations include:

• Compression ability - Does it shrink the file significantly enough?
• Ease-of-use - If the file is going to another user, will the archive be easy to extract or will it require more software to be installed?
• Password protection and/or encryption - Are these security measures required?
• Multiple volumes support - If the target medium requires the file to be split into appropriate chunks, does the format support this elegantly. For example, 650 MB for a CD.
• Repairing and recovery - If the file becomes partially corrupt, does it offer a recovery record to aid restoration of data?
• Unicode support - Does the archiver support international file names or just standard ASCII?
• System Requirements - Modern compressors such as 7-Zip do offer the ability to increase compression efficiency by using a larger dictionary (a dictionary is a reference of commonly repeated data in a compressed file), but this in turn increases memory consumption at both compression and decompression time.
• Self-extraction support - Can the archive be rolled into an executable file that provides ease of use to whomever needs to use it? (Also bear in mind you can only create a self-extractor for a single platform. Generally speaking a Windows self-extractor will not work on Linux by default, unless run through a compatibility layer like Wine).
• File system attributes - Does the compressor store relevant file system metadata and permissions that may be worth preserving at point of extraction?

Generally speaking ZIP is the most ubiquitous format, but sizes over 4 GB aren't generally supported (if at all), security support is generally regarded as poor (the standard password can be compromised with a plain-text attack, and further encryption is generally implemented as an unofficial derivative of the format by commercial ZIP software vendors).

Apart from that, most other popular formats will have some form of support on all operating systems by installing more software.

My personal choice is 7-Zip, as it has great and flexible compression; despite it having a peculiar user interface on Windows. There are de-compressors for Linux and Mac OS X (although not GUI based as standard).