data archival and compression format
introduced for WinRAR (Eugene
Roshal, 1995), a file archiver utility released for MS Windows
RAR compression is based on Lempel-Ziv LZSS and prediction
by partial matching PPMd/PPMII
(Dmitry Shkarin), which provides very good compression ratio, almost
comparable with 7Z.
format also features data
(if optional recovery records are used while creating the archive), and
optional AES based encryption.
"RAR" acronym stands for "Roshal
ARchive", from the surname of the
PeaZip, freeware and open source archiver utility, can open and extract RAR files on Linux and
Windows, using the
Open Source code written by Igor Pavlov in 7-Zip and
its POSIX port p7zip project.
Open Source free RAR archiver utility is available: UNRAR is available
as royalty-free and open
software for allowing extraction of RAR archives both on Linux and
Microsoft Windows, but with the clause of not reverse engineering the
implementing RAR compression which prevents creation of royalty free
rar archivers & compressors.
engineering clause about the RAR
compression algorithm and code apply as well for any rewritten version,
so no Free Software,
royalty free RAR archiver and compressor can be created under current
Consequently, due to RAR's license constrains, no free software can be
natively capable of writing RAR archives (which is required both for
creation, update and repairing), unless calling Windows-only WinRar's
requires having WinRar (shareware, free for 40 days only) downloaded
installed as a separate product.
Please note that WinRar license's time trial legal limitations apply to
any part of the package (as i.e. rar.exe) as well, even if it does not
warning screen as the main WinRar's GUI executable.
Archive format dropdown menu in PeaZip compression screen allows to
select "Custom" format, which lets the user select an arbitrary
compressor executable, enter command parameters for it, and to
customize the syntax of the generated script string in order to adapt
to the syntax the compressor is expecting.
With WinRar installed in
the system (as there is no third parts tool capable of rar
compression due rar format licensing restrictions), you can set
interface to use rar.exe to create
archive through PeaZip's GUI.
|Set compression to Custom format
Chose "Custom" format in
Following steps will only be needed the first time you set RAR as
custom compression formats (or if you change custom compressor),
afterwards settings will be remembered and you can select RAR format
simply chosing "Custom" compression.
RarLabs rar.exe path
Go to "Advanced" tab to tell PeaZip how to use
First information needed is where the rar.exe
executable is saved in
Usually, it is in C:\Program Files\WinRAR\Rar.exe or C:\Program
Use the file dialog on the right of "Executable" field to
pick the file.
rar command line parameters
Write "a" in "Parameters" filed, which
stands for "create archive" command for rar.exe syntax
In "Syntax" dropdown menu it should
already be selected the second entry of the list:
output, input", in this way rar.exe will be able to parse PeaZip's
commands in the correct order.
|More information on
External online resources: RarLabs WinRAR official
domain, Lempel-Ziv LZSS and prediction
by partial matching PPMd/PPMII
Topics and serach suggestions: create rar archives, compress data to
free rar archiver licensing issues, Roshal Archive format intellectual
property, freeware RAR utilities, rar compression
add files to .RAR package, WinRar archiving function, RarLabs, how to