ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How To Open And Extract Contents Of A RAR File

Updated on August 20, 2010

How to open and read the contents of a RAR file

RAR means Roshal AR-chive. It is a archive file format which is not documented .It gives support for compression of data, recovery of data in case of loss of date due to error, and file spanning.

Eugene Roshal is the the one who successfully developed the RAR format. He was a software engineer.

Extension used by RAR is of 2 types:

.rar is used for the data volume set

.rev for the recovery volume set.

Note that in the previous editions smaller files of a split RAR-archive used the extensions .rar, .r00, .r01, .r02 etc. Now it has changed.

Version 1 and Version 2 of archive files were used in conjunction with a p archive file archiver to produce parity files for recovery of error when using not so reliable file transmission and storage media such as satellite transmission, and CD ROM's..

In Version 3 the need for third party post-processing was eliminated. Great Job.

Algorithm used in RAR for compression

Version 3 of RAR is based on

  • Lempel-Ziv and
  • Prediction by partial matching compression

Different versions of the RAR form had been mentioned by third party developers:

  • RAR (original)

  • RAR2

  • RAR3 (current version) .

In RAR 3 you can notice these following changes

  • File extensions changed from {volume name}.rar, {volume name}.r00, {volume name}.r01, etc. to {volume name}.part001.rar, {volume name}.part002.rar, etc.
  • Algorithm used for encryption successfully changed to Advanced Encryption Standard or AES .It has 128 bit key length.
  • Encryption in a file is performed for both data and headers.
  • Compression algorithm was considerably improved using 4MB dictionary size, PPMII algorithm for file data, and selective preprocessing algorithms based on platform and source file type.
  • Optional creation of "recovery volumes" (.rev files) with redundancy data which can be used to reconstruct missing files in a volume set.
  • Support for larger archive files (more than 9 GB)was provided
  • Support for Unicode names came with this version.


Software

RAR files can be produced with commercial soft-wares WinRAR, RAR, and software that has permission from the licensor, Alexander Roshal (Eugene's brother) only.RAR for Pocket PC is the only free to use option available for creating RAR files.

Third-party applications that can only read (uncompressed) RAR files include:

  • WinZip ,
  • RarZilla
  • 7-Zip
  • IZArc
  • PeaZip,
  • Zipeg
  • ALZip

WinRAR

WinRAR is commercial software (A 40-day trial is available for download available for Windows PC's. It is the only GUI utility that can create modern RAR files (Version three RAR ).

WinRAR command line equivalent, RAR, is also commercial software (trial version is available), for Windows Linux and Mac. Additionally, the unrar tool from the same distributor can be used on the relevant platforms to extract RAR files but not to write them.

Initially programs for RAR file format was developed for packing and unpacking RAR files, originally for DOS(disk operating system).Later programs were created for other platforms.

WinRAR, which is a popular version is distributed as trial-ware, requiring payment after 40 days (although it can still be used after this period, pop-up screen appears); trial versions of this program are also available for Linux and Mac OS X, though they are all called simply "RAR".

Other programs

There is a free software decompression library called "unrarlib", licensed under the GPL, but it can only decompress archives created by RAR versions up to 2.x. Archives produced by RAR 2.9 and later uses different format which is not supported by the free library.

Stuff-it Expander and Free RAR Extract Frog also decodes RAR files.

The open source software archiver called 7-Zip decompresses newer RAR files using a closed-source free of charge plug-in under the "unRAR license"; the license makes the plug-in source-available but not free software.

The Unarchiver is another unarchiver which can decompress newer RAR files.

There are some free software Linux archivers like File Roller, Ark, and Xarchiver .They can also decompress RAR files.

There is a free Dynamic-link library (DLL) called UnRAR. Dll which can be obtained from the official site of winrar.


Comparison with other compression algorithms


You will notice that the compression operations of RAR are usually slower than compressing the same data with other compression algorithms like ZIP. But RAR gives you a better compression.RAR uses specialized routines while dealing with multimedia files.

Also the optional production of "recovery volumes" (.rev files) with redundancy data is very helpful in reconstructing missing files in a volume set.





working

This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://corp.maven.io/privacy-policy

Show Details
Necessary
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
Features
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Marketing
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Statistics
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
ClickscoThis is a data management platform studying reader behavior (Privacy Policy)