brad@looking.UUCP (Brad Templeton) (02/14/89)
Recently I have written a new system I call ABE which is a bulletproof encoder for transmitting binaries through dangerous waters. It does all the uuencode style system does, plus a lot more. Here's a brief feature list: ABE Ascii-Binary Encoding System by B. Templeton ABE is a replacement for uuencode/uudecode designed to deal with all the typical problems of USENET transmission, along with those of other media. Advantages are: Files are often smaller, and compress well. All printable characters map to themselves, so strings in binaries are readable right in the encoding. All lines are indexed, so sort(1) can repair any random scrambling of lines or files. (This can be turned off.) Extraneous lines (news headers, comments, signatures etc.) are ignored, even in the middle of encodings. A PD tiny decoder is available to include with files for first time users. Files can be split up automatically into equal sized blocks. Blocks can contain redundant information so that the decoder can handle blocks in any order, even with reposted duplicates and extraneous articles. Files with blank regions can be constructed from multi-part encodings with damaged blocks. Multiple files can be placed in one encoding. The decoder is extremely general and configurable, and supports many features not currently found in the encoder, but which other encoder writers might fight useful. In general, a redundant ABE encoding posted to a typical newsgroup over a certain article region can be decoded with something as simple as: dabe /usr/spool/news/comp/binaries/group/3[45]? Where it doesn't matter much if there are postings in a random order, duplicate postings, or inserted articles on other topics. Ie. exactly all the things that are a pain about usenet (or mail) binaries. (You can usually run dabe right on your entire mailbox.) The ABE encoder (and decoder) support 3 different encoding formats. One uses all 94 printable ASCII characters, the other avoids characters that have trouble in ASCII-EBCDIC translations, and the 3rd is the UUENCODE format. (ABE can make files decodable by a typical uudecode program.) ================= Anyway, before sending it out into the world, I would appreciate it if a few of you would try it out for me first. No real press, but if you can ftp, you will find it in the anonymous ftp directory of math.waterloo.edu as "abe.shar.Z" -- it is only about 46K in size. If you can't FTP and you must test, drop me some mail. Thanks. -- Brad Templeton, Looking Glass Software Ltd. -- Waterloo, Ontario 519/884-7473