shell-command parameters

shell-command parameters

[rustom]

When I issue a shell command which is a pipeline such as say

echo 1 2 3; echo 4 5

in a normal shell I should get
1 2 3
4 5

However in windows for emacs shell-command (M-!) I get
1 2 3;echo 4 5

Any clues??

The worst part is it sometimes works and sometimes not!

Re: shell-command parameters

[Chetan]

rustom <rustompmody@gmail.com> writes:

> When I issue a shell command which is a pipeline such as say
>
> echo 1 2 3; echo 4 5
>
> in a normal shell I should get
> 1 2 3
> 4 5
>
> However in windows for emacs shell-command (M-!) I get
> 1 2 3;echo 4 5
>
> Any clues??
>
> The worst part is it sometimes works and sometimes not!

Do you mean you get different results on Windows or between Windows
and other systems?

If it is the latter, isn't that the expected behaviour?

Re: shell-command parameters

[Peter Dyballa]

> rustom <rustompmody@gmail.com> writes:
>
>> When I issue a shell command which is a pipeline such as say
>>
>> echo 1 2 3; echo 4 5


This no pipeline, it's a sequence.

In a pipeline stdout of command a becomes stdin of command b.

--
Greetings

   Pete

The problem with the French is that they don't have a word for «  
entrepreneur ».
				– George W. Bush

Re: shell-command parameters

[Eli Zaretskii]

> From: Chetan <Chetan.xspam@xspam.sbcglobal.net>
> Date: Mon, 05 Jan 2009 05:35:45 -0800
> 
> rustom <rustompmody@gmail.com> writes:
> 
> > When I issue a shell command which is a pipeline such as say
> >
> > echo 1 2 3; echo 4 5
> >
> > in a normal shell I should get
> > 1 2 3
> > 4 5
> >
> > However in windows for emacs shell-command (M-!) I get
> > 1 2 3;echo 4 5
> >
> > Any clues??
> >
> > The worst part is it sometimes works and sometimes not!
> 
> Do you mean you get different results on Windows or between Windows
> and other systems?
> 
> If it is the latter, isn't that the expected behaviour?

Yes, it certainly is.

On Windows, if you want 2 commands on a single line, use `&' instead
of `;', as in

   echo 1 2 3 & echo 4 5

Re: shell-command parameters

[Chetan]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Chetan <Chetan.xspam@xspam.sbcglobal.net>
>> Date: Mon, 05 Jan 2009 05:35:45 -0800
>> 
>> rustom <rustompmody@gmail.com> writes:
>> 
>> > When I issue a shell command which is a pipeline such as say
>> >
>> > echo 1 2 3; echo 4 5
>> >
>> > in a normal shell I should get
>> > 1 2 3
>> > 4 5
>> >
>> > However in windows for emacs shell-command (M-!) I get
>> > 1 2 3;echo 4 5
>> >
>> > Any clues??
>> >
>> > The worst part is it sometimes works and sometimes not!
>> 
>> Do you mean you get different results on Windows or between Windows
>> and other systems?
>> 
>> If it is the latter, isn't that the expected behaviour?
>
> Yes, it certainly is.
>
> On Windows, if you want 2 commands on a single line, use `&' instead
> of `;', as in
>
>    echo 1 2 3 & echo 4 5
Or
echo 1 2 3 && echo 4 5 and get the same result everywhere

Re: shell-command parameters

[Eli Zaretskii]

> From: Chetan <Chetan.xspam@xspam.sbcglobal.net>
> Date: Mon, 05 Jan 2009 13:40:27 -0800
> 
> > On Windows, if you want 2 commands on a single line, use `&' instead
> > of `;', as in
> >
> >    echo 1 2 3 & echo 4 5
> Or
> echo 1 2 3 && echo 4 5 and get the same result everywhere

The semantics of ;/& and && is not the same.  With `echo', the
difference hardly matters, but in general, the former will always run
both commands, while the latter will sometimes only run the first one.

Re: shell-command parameters

[rustom]

On Jan 6, 9:05 am, Eli Zaretskii <e...@gnu.org> wrote:
> > From: Chetan <Chetan.xs...@xspam.sbcglobal.net>
> > Date: Mon, 05 Jan 2009 13:40:27 -0800
>
> > > On Windows, if you want 2 commands on a single line, use `&' instead
> > > of `;', as in
>
> > >    echo 1 2 3 & echo 4 5
> > Or
> > echo 1 2 3 && echo 4 5 and get the same result everywhere
>
> The semantics of ;/& and && is not the same.  With `echo', the
> difference hardly matters, but in general, the former will always run
> both commands, while the latter will sometimes only run the first one.

Thanks.

I guess mostly one needs cmd1 && cmd2.  And the unix equivalent of
cmd1 ; cmd2 is cmd1 & cmd2.

But I still wonder what shell is running in windows emacs?

Re: shell-command parameters

[Kevin Rodgers]

rustom wrote:
> On Jan 6, 9:05 am, Eli Zaretskii <e...@gnu.org> wrote:
>>> From: Chetan <Chetan.xs...@xspam.sbcglobal.net>
>>> Date: Mon, 05 Jan 2009 13:40:27 -0800
>>>> On Windows, if you want 2 commands on a single line, use `&' instead
>>>> of `;', as in
>>>>    echo 1 2 3 & echo 4 5
>>> Or
>>> echo 1 2 3 && echo 4 5 and get the same result everywhere
>> The semantics of ;/& and && is not the same.  With `echo', the
>> difference hardly matters, but in general, the former will always run
>> both commands, while the latter will sometimes only run the first one.
> 
> Thanks.
> 
> I guess mostly one needs cmd1 && cmd2.  And the unix equivalent of
> cmd1 ; cmd2 is cmd1 & cmd2.
> 
> But I still wonder what shell is running in windows emacs?

,----[ C-h v shell-file-name RET ]
| shell-file-name is a variable defined in `src/callproc.c'.
| Its value is "/bin/bash"
|
|
| Documentation:
| *File name to load inferior shells from.
| Initialized from the SHELL environment variable, or to a system-dependent
| default if SHELL is not set.
|
| You can customize this variable.
|
| [back]
`----

Looking at callproc.c, the system-dependent default is "/bin/sh".

-- 
Kevin Rodgers
Denver, Colorado, USA

Re: shell-command parameters

[rustom]

On Jan 6, 7:29 pm, Kevin Rodgers <kevin.d.rodg...@gmail.com> wrote:
> rustom wrote:
> > But I still wonder what shell is running in windows emacs?
>
> ,----[ C-h v shell-file-name RET ]
> | shell-file-name is a variable defined in `src/callproc.c'.
> | Its value is "/bin/bash"


Thanks. Thats the variable I was looking for.
It turns out to be /path/to/emacs/bin/cmdproxy.exe
Changing it to c:/cygwin/bin/bash.exe makes it work as expected (by a
unix user)

I wonder does emacs go out of its way to make life difficult for a
windows user?  MS does a good job of this without help from emacs :-)
I mean 'cmd' has one expected behavior; shell has another. Why make
the 'shell' variable point to a cmd imitation?

(Sorry to grumble)

Is it possible to remember the calls to these shell calls (made with
M-!) across emacs invocations -- the way bash remembers?

Re: shell-command parameters

[Andreas Politz]

rustom wrote:
> On Jan 6, 7:29 pm, Kevin Rodgers <kevin.d.rodg...@gmail.com> wrote:
>> rustom wrote:
>>> But I still wonder what shell is running in windows emacs?
>> ,----[ C-h v shell-file-name RET ]
>> | shell-file-name is a variable defined in `src/callproc.c'.
>> | Its value is "/bin/bash"
> 
> 
> Thanks. Thats the variable I was looking for.
> It turns out to be /path/to/emacs/bin/cmdproxy.exe
> Changing it to c:/cygwin/bin/bash.exe makes it work as expected (by a
> unix user)
> 
> I wonder does emacs go out of its way to make life difficult for a
> windows user?  MS does a good job of this without help from emacs :-)
> I mean 'cmd' has one expected behavior; shell has another. Why make
> the 'shell' variable point to a cmd imitation?
> 
> (Sorry to grumble)
> 
> Is it possible to remember the calls to these shell calls (made with
> M-!) across emacs invocations -- the way bash remembers?

savehist-mode

?

-ap

Re: shell-command parameters

[Eli Zaretskii]

> From: rustom <rustompmody@gmail.com>
> Date: Tue, 6 Jan 2009 07:02:14 -0800 (PST)
> 
> On Jan 6, 7:29 pm, Kevin Rodgers <kevin.d.rodg...@gmail.com> wrote:
> > rustom wrote:
> > > But I still wonder what shell is running in windows emacs?
> >
> > ,----[ C-h v shell-file-name RET ]
> > | shell-file-name is a variable defined in `src/callproc.c'.
> > | Its value is "/bin/bash"
> 
> 
> Thanks. Thats the variable I was looking for.
> It turns out to be /path/to/emacs/bin/cmdproxy.exe
> Changing it to c:/cygwin/bin/bash.exe makes it work as expected (by a
> unix user)
> 
> I wonder does emacs go out of its way to make life difficult for a
> windows user?  MS does a good job of this without help from emacs :-)
> I mean 'cmd' has one expected behavior; shell has another. Why make
> the 'shell' variable point to a cmd imitation?

cmdproxy is not an imitation of CMD, it's a _proxy_ which eventually
invokes the real CMD.EXE.  Thus its name.

As to the reasons why this is needed, here's the relevant commentary
from cmdproxy.c:

   Accepts subset of Unix sh(1) command-line options, for compatibility
   with elisp code written for Unix.  When possible, executes external
   programs directly (a common use of /bin/sh by Emacs), otherwise
   invokes the user-specified command processor to handle built-in shell
   commands, batch files and interactive mode.

   The main function is simply to process the "-c string" option in the
   way /bin/sh does, since the standard Windows command shells use the
   convention that everything after "/c" (the Windows equivalent of
   "-c") is the input string.

Re: shell-command parameters

[Barry Margolin]

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In article 
<dd6000ea-5ab7-411c-966d-a715f68c94c9@d42g2000prb.googlegroups.com>,
 rustom <rustompmody@gmail.com> wrote:

> On Jan 6, 7:29 pm, Kevin Rodgers <kevin.d.rodg...@gmail.com> wrote:
> > rustom wrote:
> > > But I still wonder what shell is running in windows emacs?
> >
> > ,----[ C-h v shell-file-name RET ]
> > | shell-file-name is a variable defined in `src/callproc.c'.
> > | Its value is "/bin/bash"
> 
> 
> Thanks. Thats the variable I was looking for.
> It turns out to be /path/to/emacs/bin/cmdproxy.exe
> Changing it to c:/cygwin/bin/bash.exe makes it work as expected (by a
> unix user)
> 
> I wonder does emacs go out of its way to make life difficult for a
> windows user?  MS does a good job of this without help from emacs :-)
> I mean 'cmd' has one expected behavior; shell has another. Why make
> the 'shell' variable point to a cmd imitation?

I think the expectation is that shell-command should behave similarly to 
typing the command in the system's normal command line interface.  Why 
would a Windows user expect Unix-like behavior?

-- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
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