UUencode vs. UUdecode vs. yEnc

Getting those binary files onto newsgroups aka Unix to Unix encode

First lets start with a definition of UUencodeUUdecode the conversion of a binary file e.g. movies MP3 pictures software etc. tofrom an ASCII text file so it can be sent as an attachment via email or posteddownloaded tofrom a newsgroup. UUencode converts nontext files binary files as text so that they can be included in a mail messages and newsgroup posts. When the message is received the recipient or their newsreader application runs UUdecode to convert it back to its original state.

In essence software usually included within the newsreader is used to transform binary files into text characters and vice versa. You can tell youre looking at an UUencoded post if it starts with the line begin 644 somefilename.ext followed by a jumbled series of characters.

The problem with UUencoding is it significantly increases the filesize as compared to the original when posted to Usenet. Some say around 35 increase thus explaining why Usenet traffic nowadays is approximately 5001000GB per day.

A new way to encode postings yEnc

yEnc is a new encoding method which purportedly offers better transmission for binaries on Usenet. Posts subjects often but not always have yEnc spelled out which helps readers determine the type of binaries post.

The problem with this new encoding method is not surprising many newsreaders dont support yEnc thus making it difficult to decode yEnc encoded files without an additional application. Fortunately the more popular newsreader applications have added support for yEnc into their software. See a list of newsreaders that support yEnc.

To find out more about yEnc visit their homepage.

Other encoding methods

Youre best bet if youre going to be posting binaries is to use UUencoding. Its been around for years almost all newsreaders support encodingdecoding and is the most common form used by folks posting to Usenet newsgroups.

Other less common encoding methods for Usenet posts are BASE64 BinHex Quoted Printable. See their technical definitions below

Base64 encoding for binary data consisting only of 64 encoding characters AZ az 09 that are a subset of USASCII.

BinHex BINary HEXadecimal another method for converting nontext files nonASCII into ASCII.

Quoted Printable encoding largely consisting of octets that correspond to printable characters in the ASCII character set. It encodes the data in such a way that the resulting octets are unlikely to be modified when posted. If the data being encoded are mostly ASCII text the encoded form of the data remains largely recognizable by humans. A body which is entirely ASCII may also be encoded in QuotedPrintable to ensure the integrity of the data should the message pass through a charactertranslating andor linewrapping gateway.