[9fans] bug in Plan 9 -ms macros?

[9fans] bug in Plan 9 -ms macros?

[Mike Haertel]

With the following input, formatted using eqn | troff -ms,
one equation is centered, the other isn't.

.LP
.EQ
x = y
.EN
.EQ
x mark = y
.EN

Re: [9fans] bug in Plan 9 -ms macros?

[Ralph Corderoy]

Hi,

> With the following input, formatted using eqn | troff -ms,
> one equation is centered, the other isn't.
>
> ..LP
> ..EQ
> x = y
> ..EN
> ..EQ
> x mark = y
> ..EN

As an aside, is there some problem with the mail<->news gateway?  The
dots turned up doubled on comp.os.plan9.


Ralph.

Re: [9fans] bug in Plan 9 -ms macros?

[Boyd Roberts]

> As an aside, is there some problem with the mail<->news gateway?  The
> dots turned up doubled on comp.os.plan9.

could be a blendmail/smtp thing.  there's some option to blendmail (sic)
to double up on leading dots to prevent premature end of the input to
a DATA command.  it's also written up in the smtp rfc [rfc821 / std10]:

4.5.2.  TRANSPARENCY

         Without some provision for data transparency the character
         sequence "<CRLF>.<CRLF>" ends the mail text and cannot be sent
         by the user.  In general, users are not aware of such
         "forbidden" sequences.  To allow all user composed text to be
         transmitted transparently the following procedures are used.

            1. Before sending a line of mail text the sender-SMTP checks
            the first character of the line.  If it is a period, one
            additional period is inserted at the beginning of the line.

            2. When a line of mail text is received by the receiver-SMTP
            it checks the line.  If the line is composed of a single
            period it is the end of mail.  If the first character is a
            period and there are other characters on the line, the first
            character is deleted.

sounds like a bug.  why am i not suprised?

it may also be an issue with nntp.

[9fans] bug in Plan 9 -ms macros?

[rob pike]

Brian Kernighan writes:


It's always been that way, and the manual has said so for 25 years:

For reasons too complicated to talk about,
when you use
.I eqn
and
.CW -ms ,
use either
.CW .EQ\ I
or
.CW .EQ\ L ;
.CW mark
and
.CW lineup
don't work with centered equations.

Feature, not bug.

On Fri, 14 Sep 2001, rob pike wrote:

> From: mike@ducky.net
> Date: Fri Sep 14 21:57:28 EDT 2001
> To: 9fans@cse.psu.edu
> Subject: [9fans] bug in Plan 9 -ms macros?
>
> With the following input, formatted using eqn | troff -ms,
> one equation is centered, the other isn't.
>
> .LP
> .EQ
> x = y
> .EN
> .EQ
> x mark = y
> .EN
>