[mod.protocols] Formatting Query

bc@cyb-eng.UUCP (09/18/86)

> [...]
> This clearly makes it illegal for SMTP mailers to expand tabs.  On the
> [...]
> This clearly suggests that mail-agents expand tabs before submitting
> them to mailers.
> 
> Meanwhile, if you use tabs in formatting such that the width of a tab
> stop affects the content of your message (e.g., in drawing pictures),
> other people will get what you deserve.
> 
> joe

I admit right off that I have little experience with mailers.  One point
I feel a layman can legitimately make, however, is that:

	If I have software on my end that knows what a tab means within
	a given context, and if I want to mail this file to someone else
	whose software is also aware of the context and of the meaning
	of tabs within that context, I think I should be able to do this
	without the mailer screwing up the situation.

Perhaps this is obvious and is no problem, in which case, please do not
followup to this article of concern.

jc@cdx39.UUCP (09/19/86)

> My system (a Xerox Star) displays mail in a proportionally spaced font,
> making all diagrams hard to read without changing the font.
> I'm not sure if this is a bug or a feature, however.
> 
> In general, I think that having the mailer expand the tabs would be a bad
> idea.  There might be reasons for wanting the tabs in the message and it shouldn't
> be impossible to do this.  

For those of us using many Unix systems, there is a very good reason.
I keep finding myself helping people who can't get make(1) to work,
and can't see anything wrong with their makefiles.  Invariably, what
turns out to be wrong is that something has expanded the tabs into
spaces.  Most (but not all) versions of make *require* that rule 
lines start with a TAB, and spaces aren't acceptable.  Anything 
that expands tabs will destroy a makefile.

Recently, someone installed a great new editor on a lot of systems
around here, and it expands tabs to spaces....

mark@cbosgd.ATT.COM (Mark Horton) (09/20/86)

In article <8609181416.AA15967@SALLY.UTEXAS.EDU> bc@cyb-eng.UUCP writes:
>  If I have software on my end that knows what a tab means within
>  a given context, and if I want to mail this file to someone else
>  whose software is also aware of the context and of the meaning
>  of tabs within that context, I think I should be able to do this
>  without the mailer screwing up the situation.

I think this is the heart of the matter: whether the implementors do
or do not intend it, people use electronic mail to transfer files.

Nobody expects mailers to leave binary files alone, so they use uuencode
or a similar method to make them mailer-safe.  But my experience is that
if a file is plain text (and most people seem to include tabs in this
definition) they don't bother, they just mail it.  No amount of user
education is likely to change this.

From this I conclude that

(1) mailers, including user agents and transfer agents, should leave messages
alone as much as possible when transporting them.

(2) people mailing formatted documents should expand tabs first, or
else be willing to put up with ragged displays if the person they are
sending them to has different tab settings.

(3) Everything is fine currently, except for Multics, which (a) has
unusual tab settings, and (b) expands tabs in the mailer.

	Mark