documentation typo: `--terminal' fails

documentation typo: `--terminal' fails

[Robert J. Chassell]

When I run both in an xterm in an X windowing system and in a console
with no X:

    $ /usr/local/src/emacs/src/emacs -Q -D --terminal

we see

    emacs: Option `--terminal' requires an argument

so the documentation in

    (info "(emacs)Initial Options")

is wrong.  It says:

    `-t DEVICE'
    `--terminal=DEVICE'
         Use DEVICE as the device for terminal input and output.
         `--terminal' implies `--no-window-system'.

However, the following succeeds in both:

    `-nw'
    `--no-window-system'
         Don't communicate directly with the window system, disregarding the
         `DISPLAY' environment variable even if it is set.  This means that
         Emacs uses the terminal from which it was launched for all its
         display and input.

Today's GNU Emacs CVS snapshot, Mon, 2008 Feb 18  10:46 UTC
GNU Emacs 23.0.60.5 (i686-pc-linux-gnu, GTK+ Version 2.12.5)

-- 
    Robert J. Chassell                          GnuPG Key ID: 004B4AC8
    bob@rattlesnake.com                         bob@gnu.org
    http://www.rattlesnake.com                  http://www.teak.cc

Re: documentation typo: `--terminal' fails

[Andreas Schwab]

"Robert J. Chassell" <bob@rattlesnake.com> writes:

> When I run both in an xterm in an X windowing system and in a console
> with no X:
>
>     $ /usr/local/src/emacs/src/emacs -Q -D --terminal
>
> we see
>
>     emacs: Option `--terminal' requires an argument
>
> so the documentation in
>
>     (info "(emacs)Initial Options")
>
> is wrong.  It says:
>
>     `-t DEVICE'
>     `--terminal=DEVICE'
>          Use DEVICE as the device for terminal input and output.
>          `--terminal' implies `--no-window-system'.

In which way is this wrong?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: documentation typo: `--terminal' fails

[Robert J. Chassell]

   >     `-t DEVICE'
   >     `--terminal=DEVICE'
   >          Use DEVICE as the device for terminal input and output.
   >          `--terminal' implies `--no-window-system'.

   In which way is this wrong?

It fails to run Emacs although

    $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system

does.

-- 
    Robert J. Chassell                          GnuPG Key ID: 004B4AC8
    bob@rattlesnake.com                         bob@gnu.org
    http://www.rattlesnake.com                  http://www.teak.cc

Re: documentation typo: `--terminal' fails

[Stefan Monnier]

>> `-t DEVICE'
>> `--terminal=DEVICE'
>>      Use DEVICE as the device for terminal input and output.
>>      `--terminal' implies `--no-window-system'.

>    In which way is this wrong?
> It fails to run Emacs although
>     $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system
> does.

Because you forgot the DEVICE argument, which is clearly required
according to the documentation you quoted.


        Stefan

Re: documentation typo: `--terminal' fails

[Robert J. Chassell]

    >> `-t DEVICE'
    >> `--terminal=DEVICE'
    >>      Use DEVICE as the device for terminal input and output.
    >>      `--terminal' implies `--no-window-system'.

    >    In which way is this wrong?
    > It fails to run Emacs although
    >     $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system
    > does.

    Because you forgot the DEVICE argument, which is clearly required
    according to the documentation you quoted.

No, the documentation clearly says that

    `--terminal' implies `--no-window-system'

and neither `--terminal' nor `--no-window-system' say they need an argument.

If the `--terminal' for `--no-window-system' needed a DEVICE argument
I would expect it to say

    `--terminal=DEVICE' implies `--no-window-system'

but it does not.

Perhaps this trouble is an ambiguity of the documentation?


    > It fails to run Emacs although

    In which way does it fail when used as documented?

    >
    >     $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system
    >
    > does.

    Does what?

/usr/local/src/emacs/src/emacs -Q -D --no-window-system 
runs an instance of Emacs.  

-- 
    Robert J. Chassell                          GnuPG Key ID: 004B4AC8
    bob@rattlesnake.com                         bob@gnu.org
    http://www.rattlesnake.com                  http://www.teak.cc

Re: documentation typo: `--terminal' fails

[Stefan Monnier]

>>> `-t DEVICE'
>>> `--terminal=DEVICE'
>>> Use DEVICE as the device for terminal input and output.
>>> `--terminal' implies `--no-window-system'.

>> In which way is this wrong?
>> It fails to run Emacs although
>> $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system
>> does.

>     Because you forgot the DEVICE argument, which is clearly required
>     according to the documentation you quoted.

> No, the documentation clearly says that

>     `--terminal' implies `--no-window-system'

But the documentation also doesn't mention that --terminal is
a valid argument.  So I think your interpretation is pretty far fetched,
but obviously you disagree.  I suggest we replace "`--terminal'" with
"This argument" or just "This".


        Stefan

Re: documentation typo: `--terminal' fails

[Andreas Schwab]

"Robert J. Chassell" <bob@rattlesnake.com> writes:

>     >> `-t DEVICE'
>     >> `--terminal=DEVICE'
>     >>      Use DEVICE as the device for terminal input and output.
>     >>      `--terminal' implies `--no-window-system'.
>
>     >    In which way is this wrong?
>     > It fails to run Emacs although
>     >     $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system
>     > does.
>
>     Because you forgot the DEVICE argument, which is clearly required
>     according to the documentation you quoted.
>
> No, the documentation clearly says that
>
>     `--terminal' implies `--no-window-system'
>
> and neither `--terminal' nor `--no-window-system' say they need an argument.

The doc clearly says that --terminal requires an argument.

> If the `--terminal' for `--no-window-system' needed a DEVICE argument
> I would expect it to say
>
>     `--terminal=DEVICE' implies `--no-window-system'

The argument is not part of the option name.

> Perhaps this trouble is an ambiguity of the documentation?

There is no ambiguity in referring to the option as --terminal.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: documentation typo: `--terminal' fails

[Andreas Schwab]

"Robert J. Chassell" <bob@rattlesnake.com> writes:

>    >     `-t DEVICE'
>    >     `--terminal=DEVICE'
>    >          Use DEVICE as the device for terminal input and output.
>    >          `--terminal' implies `--no-window-system'.
>
>    In which way is this wrong?
>
> It fails to run Emacs although

In which way does it fail when used as documented?

>
>     $ /usr/local/src/emacs/src/emacs -Q -D --no-window-system
>
> does.

Does what?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
PGP key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: documentation typo: `--terminal' fails

[Robert J. Chassell]

    But the documentation also doesn't mention that --terminal is
    a valid argument.  

Since it says      `--terminal' implies `--no-window-system'.
I think it is fair to presume that `--terminal' is a valid argument.

    I suggest we replace "`--terminal'" with
    "This argument" or just "This".

That does not make it the same as `--no-window-system' or `-nw' which
is how I understand the documentation
     `--terminal' implies `--no-window-system'.

Incidently, 
    (info "(emacs) Emacs Invocation")
says

    GNU Emacs supports command line arguments to request various actions
    when invoking Emacs.

`--terminal=DEVICE', `--display=DISPLAY', and `--no-window-system' are
called `initial options' both in that node and in the subnode
    (info "(emacs) Initial Options")


    > If the `--terminal' for `--no-window-system' needed a DEVICE argument
    > I would expect it to say
    >
    >     `--terminal=DEVICE' implies `--no-window-system'

    The argument is not part of the option name.

Perhaps to an expert that is true, but when the documentation says
    `--terminal' implies `--no-window-system'
I do not expect it to mean
    `--terminal=DEVICE' implies `--no-window-system'
That is why I asked, 

    Perhaps this trouble is an ambiguity of the documentation?

-- 
    Robert J. Chassell                          GnuPG Key ID: 004B4AC8
    bob@rattlesnake.com                         bob@gnu.org
    http://www.rattlesnake.com                  http://www.teak.cc

Re: documentation typo: `--terminal' fails

[Stefan Monnier]

> That does not make it the same as `--no-window-system' or `-nw' which
> is how I understand the documentation
>      `--terminal' implies `--no-window-system'.

"Implies" is not the same as "is identical to".  An implication
is unidirectional.


        Stefan