Subject: Re: bin/2226: minor inaccuracy in uuencode.format(5) manual page
To: None <Chris_G_Demetriou@UX2.SP.CS.CMU.EDU>
From: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
List: netbsd-bugs
Date: 03/17/1996 12:12:06
>> The uuencode(5) manual page says that the encoding of the final zero
>> length line is an ASCI space.  This is incorrect; a single character
>> ` is used.

> While this may be true for the NetBSD version of uuencode, it's
> definitely not true for all uuencodes.  For instance, the ULTRIX
> version _does_ use a space.

> Looking at the SCCS logs on vangogh, i see that the change was
> brought in back in 1985 (!!), and was part of "bug fixes and changes
> from Rick Adams."  Sounds like the format was changed, the docs
> weren't updated, and the old format is still decoded because some
> systems still use it.

As I understand it, the format was changed for better robustness in the
face of mailers that mangle trailing whitespace (strip it, pad to 80
columns, that sort of thing).  The new format never uses whitespace for
anything (except as a separator on the "begin" line, of course).

Note that because space and backquote have such similar binary patterns
(00100000 and 01100000) code for unpacking uuencoded text in the
simple-minded way, by subtracting 32 and masking of everything but the
low six bits, will treat them identically.  (Which is doubtless why `
was chosen, so that old uudecodes would have a fighting chance of
understanding the new format.)

Personally, I'd argue that any RFC that says that space must be used
instead of backquote is out of date and should be ignored, at least on
that point. :-)

					der Mouse

			    mouse@collatz.mcrcim.mcgill.edu