How to work with binaries from Usenet newsgroups

There are many binary files you can find in the Usenet groups which can be viewed and/or listened too, this includes MP3/OGG audio files, JPG/PNG/GIF image files, and MPG/AVI/WMV video files. Please note that many of these binary files contain copyrighted materials, and downloading, combining, viewing or listening to them might be illegal where you live.

Split files

Many binaries are large enough that they have to be split into multiple parts in order to be posted and/or downloaded. In addition, because Usenet is a text-only media, the binaries have to be converted into a text friendly format, which makes the articles about 40-60% larger than the original file.

PAR, PAR2

A "Parchive" is a parity file which posters can create for multi-part binaries they post on Usenet. PAR files are used to re-create missing parts from binaries. PARv1 used files that were the same size as the original parts posted, and typically you need one parity file to fill each hole (missing part) in your binary. PAR2 files sizes are not directly based on the input file sizes, and par2 can be used to repair a large single file that is corrupted or up to 32768 files can be handled. In addition a damaged par2 file can still use the undamaged portions of the file to perform repairs. Under Unix, the utilities for dealing with parity files is typically named 'parchive' or 'par2'. Under windows a tool such as Quickpar can be used to work with the files.

RAR, R##, part##.RAR

RAR is the most commonly used multi-part file type used for posting binaries on Usenet. RAR can compress and archive multiple files into a single large RAR file or split the RAR into multiple parts for posting. This allows posters to put videos, galleries of images or entire CDs of music into a single multi-part archive which can be unpacked and has checksums and other protections to make sure what you unpack is what they posted. Posters often post PAR files with RAR files so you can replace any parts of the file which are missing on your server. Under Unix you can use the rar command to create RAR files, and the unrar commands to extract files from a RAR file. Under windows you can use Winrar (a commercial program) to combine and use RAR files.

001, ###

Some people use different programs to convert binary files to base64 format and split them up into multiple parts, most of these will have the original binaries file name with a sequence number appended (ie. foo.avi.001, foo.avi.002,etc). These can usually be combined by deleting anything outside of a begin..end block in the article, and then concatenating all the files together and decoding them. Under Unix you can use tools such as uudx or uulib to create or unpack single or multi-part postings. Under windows you can use HJSplit to re-create binaries.

Informational Files

There are various files that posters might include to help readers and users be able to locate all the pieces needed to get complete postings.

000, NFO, TXT

Posters will often create a posting with a filename ending in .000, .NFO or .TXT which contains all of the files they posted as a set. These files might contain checksums for files and/or message-id's the articles were posted with. These files are usually human readable files and can be viewed in your newsreader, or can be downloaded and viewed with 'less' or 'wordpad'.

NZB

files are an XML-based file format used for retrieving all parts of a binary from your Usenet servers. The NZB format was originally created by newzbin.com for their Usenet Indexing service. NZB files contain the message-id's of the postings and can be used to download all the parts from your NNTP server. Depending on the tool you use, an NZB file can be used to download all parts of a posting without having to know the subjects of the articles posted.

SFV

files are plain text files that typically contain the name, size and checksum for all parts of a posting. This format creates a fairly small file, but doesn't contain the message-id's for the postings. Since the file format does not contain message-id's it is necessary to view the subjects in your newsreader and download all the pieces manually.
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