Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!apple!amdahl!kim From: kim@uts.amdahl.com (Kim DeVaughn) Newsgroups: comp.binaries.ibm.pc.d Subject: Re: Freely-distributable uudecode for Unix Message-ID: Date: 16 Dec 89 13:14:52 GMT References: Organization: Amdahl Corporation, Sunnyvale, CA 94086 Lines: 37 In article , w8sdz@WSMR-SIMTEL20.ARMY.MIL (Keith Petersen) writes: > Some readers of this list have reported problems uudecoding files sent > by LISTSERV (or TRICKLE in Europe) which contain a "M" at the end of > each line and on the final line just before the "end" statement. > > The first character in each line defines the number of bytes of data > which follow on that line. If the uudecoder is working correctly the > trailing "M" should be ignored. It is added by LISTSERV to get around > problems of some mailers dropping trailing blanks. Several of the newer flavors of the uutwins (uuencode/uudecode) add a couple of characters beyond the specified line length (which is usually "M") to provide line-by-line checksums. If these chars aren't present, the uudecode just assumes there .uue was created by an older uuencode, and doesn't do any checksumming. If there are characters beyond the encoded line length, they do assume these char(s) represent a checksum, which is what's happening in this case. Some also do an overall length check at the EOF. The problem with trailing blanks is also eliminated, as they use a non-blank char in place of a blank (a ` I believe). So there are NO blanks anywhere in the .uue. This non-blank char maps to the same decode value, so this scheme is backwardly compatible with older versions of the uutwins, and doesn't break anything (or at least not any of the many flavors I've ever come across). Would you be interested in converting to the newer versions, as they do provide some additional error checking? If so, I'll be happy to email them to you or whomever the "right" person is at LISTSERV. /kim -- UUCP: kim@amdahl.amdahl.com or: {sun,decwrl,hplabs,pyramid,uunet,oliveb,ames}!amdahl!kim DDD: 408-746-8462 USPS: Amdahl Corp. M/S 249, 1250 E. Arques Av, Sunnyvale, CA 94086 BIX: kdevaughn GEnie: K.DEVAUGHN CIS: 76535,25