News Rover Usenet Newsreader -- Search and download Usenet newsgroup messages and files
News Rover. Powerful Usenet Reader.
Learn More About News Rover View Features Download Latest Version Register Your Software Explorer our Online Help Get In Touch With Us

News Rover Automatic RAR/PAR File Downloads


How To Download RAR/PAR File Sets

RAR file sets are commonly used for posting video and other large files.

News Rover has full automatic decompression of RAR files and error correction using PAR files.

With News Rover it's a snap to download and decode RAR file sets.

Here is an example of an RAR file set showing the separate sections.

In order to use the RAR decompressor built into News Rover, you should click the '-' shown at the left end of the first line to combine the sections into a single line in the message list. The combined line will have a '+' at the left end. The subject of the combined line will be the the subject of the first RAR section.

To start downloading the RAR file set double click the subject of the message line.

When you double click the combined message subject, the News Rover RAR decompression control screen is displayed.

This screen tells you how many sections there are to the RAR archive and how many individual messages (generally, each segment is made up of several messages). It also tells you how many PAR sections are present.

There are two option checkboxes that you can select:

"Download PAR sections as well as RAR sections" -- If PAR sections are available, this option will be enabled. If you check the box, News Rover will download the PAR sections as well as the RAR sections. This is recommended because News Rover can use the PAR sections to recover missing or damaged RAR sections.

"Combine and decompress when downloads finish" -- If you check this box, News Rover will begin automatically to combine and decompress the segments of the RAR file set as soon as the downloads finish. Note, if you stop News Rover and restart it, pending RAR decompressions are forgotten and you will have to use the manual method described below to combine and decompress the RAR files.

The screen has three buttons:

"Start downloading RAR archive now" -- Click this to cause News Rover to immediately begin downloading all of the segments of the RAR archive.

"Mark RAR files for later download" -- Click this to cause News Rover to "tag" the files that are part of the RAR archive for later download. A down-arrow icon will appear to the left of each file that has been marked for download. When you are ready to start the downloads, click the downward-pointing arrow icon on the News Rover toolbar.

"Delete all parts of this RAR archive" -- Click this if you want News Rover to Delete all of the RAR and PAR sections.

Click "Start downloading RAR archive now" to begin the actual downloads.

News Rover will then begin downloading all of the RAR and PAR sections. If you want to monitor the download progress of each section, you can click the '+' at the left end of the line to expand the combined list into individual parts.

Wait for all of the sections to be downloaded. Do not click the paper-clip icon for an individual section.

When the all of the sections have been downloaded, News Rover will automatically perform the RAR decompression. If there are missing or corrupt RAR sections and PAR sections are available, News Rover will automatically use the PAR sections to repair the RAR sections.

When the downloads and decompression finish, the message line that had the RAR files will be replaced with one containing the decompressed file.

You can click the paper-clip icon at the left end of the completed message to launch the attachment extracted by the RAR decompression.


Frequently Asked Questions about RAR and PAR files

What Are RAR Files?

RAR is a technique for compressing files and splitting them into multiple pieces. It is widely used for posting large files because they can be split into a set of reasonably sized segments. RAR files are similar to ZIP files in the sense that they are compressed archives that must be decompressed before you can access their contents. But RAR files are better suited for compressing large files for Usenet posting because they are designed to be split into multiple volumes.

Prior to RAR version 3.0, segments of RAR file sets had names ending with .rar, .r00, .r01, .r02, etc., so a full file posting might have file names like file.rar, file.r00, file.r01, etc. This format is still widely used.

Beginning with RAR version 3.0, a new naming convention was introduced that adds two extensions to the file name; the first indicates the part number, and the second is always ".rar". A typical file posting will have segments with names such as file.part01.rar, file.part02.rar, file.part03.rar, etc. RAR version 3.0 also introduced error recovery files with extensions of .rev, but they are rarely used because PAR files are preferred.

What are PAR files?

Often, a set of PAR files is posted accompanying an RAR file set. PAR files are parity recovery files that can be used to recovery missing or corrupted segments of an RAR file set. The PAR files usually have names such as file.part01.p01, file.part01.p02, etc.; you may also see file.part01.par, but generally PAR files begin with .p01.

If all of the segments of a RAR file set are present and valid, you do not need any of the PAR files. However, if any RAR segment is missing or corrupted, it can be recovered by using a PAR file. It takes one PAR file to recover each missing or damaged RAR segment. So if a file is posted with 10 PAR sections, up to 10 damaged or missing RAR segments can be recovered. The only exception to this is the PAR segment with the .par extension. The .par file is optional and contains only information about what files are part of the set; it does not contain recovery information. Usually, .par files are not used; they are never needed. The actual recovery PAR files begin with .p01.

PAR files are independent of each other, so a missing or damaged PAR segment will not affect the recovery as long as there are enough good PAR files to replace missing and damaged RAR files.

Version 2 PAR files have extended file names of the form "name.volnn+mm.par2". With PAR version 2, one PAR volume can be used to recover more than one missing/damaged RAR volume, and the valid portion of a damaged RAR volume can be used in the recovery process. News Rover supports both version 1 and version 2 PAR files.


News Rover home page

Download free 30-day evaluation copy of News Rover