Editing a file as root

Editing a file as root

[bhiker]

To edit a file as root, do I have to start another emacs ?
Many thanks
BH

Re: Editing a file as root

[Dan Anderson]

bhiker@free.fr writes:

> To edit a file as root, do I have to start another emacs ?

Start emacs under  a root shell or after suing  (or sudoing emacs) and
you'll start emacs running with root permissions.

-Dan

Re: Editing a file as root

[David Kastrup]

Dan Anderson <dan@mathjunkies.com> writes:

> bhiker@free.fr writes:
> 
> > To edit a file as root, do I have to start another emacs ?
> 
> Start emacs under  a root shell or after suing  (or sudoing emacs) and
> you'll start emacs running with root permissions.

If you have tramp installed (like the CVS Emacs has by default), you
can just edit the file
/su::/etc/fstab
(for example), Emacs will ask you for the root password, spawn a root
shell and use a pipe to it to send files back and forth transparently.

tramp is available as a separate package, too, if you don't like
using developer Emacsen.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: Editing a file as root

[Micha Feigin]

On Sun, Dec 14, 2003 at 10:25:41PM +0100, David Kastrup wrote:
> Dan Anderson <dan@mathjunkies.com> writes:
> 
> > bhiker@free.fr writes:
> > 
> > > To edit a file as root, do I have to start another emacs ?
> > 
> > Start emacs under  a root shell or after suing  (or sudoing emacs) and
> > you'll start emacs running with root permissions.
> 
> If you have tramp installed (like the CVS Emacs has by default), you
> can just edit the file
> /su::/etc/fstab
> (for example), Emacs will ask you for the root password, spawn a root
> shell and use a pipe to it to send files back and forth transparently.
> 
> tramp is available as a separate package, too, if you don't like
> using developer Emacsen.
> 

Actually reading the tramp documentation it would seem that the correct
way to do this is
/[su/localhost]/etc/fstab
Is it possible to make this shorter ? (dropping localhost results with
an error).
Using the way you said gives the following error:
Opening FTP connection to su...
ange-ftp-error: FTP Error: OPEN request failed: ftp: su: No address
associated with name
BTW, is there a way to do this using emacsclient?

> -- 
> David Kastrup, Kriemhildstr. 15, 44793 Bochum
> _______________________________________________
> Help-gnu-emacs mailing list
> Help-gnu-emacs@gnu.org
> http://mail.gnu.org/mailman/listinfo/help-gnu-emacs
> 

Re: Editing a file as root

[David Kastrup]

Micha Feigin <michf@post.tau.ac.il> writes:

> On Sun, Dec 14, 2003 at 10:25:41PM +0100, David Kastrup wrote:
> > Dan Anderson <dan@mathjunkies.com> writes:
> > 
> > > bhiker@free.fr writes:
> > > 
> > > > To edit a file as root, do I have to start another emacs ?
> > > 
> > > Start emacs under  a root shell or after suing  (or sudoing emacs) and
> > > you'll start emacs running with root permissions.
> > 
> > If you have tramp installed (like the CVS Emacs has by default), you
> > can just edit the file
> > /su::/etc/fstab
> > (for example), Emacs will ask you for the root password, spawn a root
> > shell and use a pipe to it to send files back and forth transparently.
> > 
> > tramp is available as a separate package, too, if you don't like
> > using developer Emacsen.
> 
> Actually reading the tramp documentation it would seem that the correct
> way to do this is
> /[su/localhost]/etc/fstab

Then you are either using an outdated tramp or XEmacs or both.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum

Re: Editing a file as root

[Sébastien Kirche]

On my system (Mac OSX 10.2.8), emacs fails or freezes after entering the 
superuser password.
"top" shows that no cpu is used by emacs, and i can get the control back 
with C-g

Here is the messages left by tramp :

Loading tramp...
Loading executable...done
Loading tramp...done
tramp: Opening connection for `<root>' using `su'...
tramp: Waiting for prompts from remote shell
tramp: Waiting 60s for prompt from remote shell
tramp: Sending password
Password:
Password:.
Password:..
Password:...
Password:....
Password:.....
Password:......
Password:.......
tramp-process-actions: Login failed

I remember recent considerations about a bad behavior of emacs on osx
and communication with sub-processes. But i wasn't able to find them again.
Maybe it is relative to my problem ?

Sébastien Kirche

Re: Editing a file as root

[gebser]

Did you try logging into the server as root from the command line...  
i.e., without using tramp?


At 11:47 (UTC+0100) on Mon, 15 Dec 2003 Sébastien Kirche said:

= On my system (Mac OSX 10.2.8), emacs fails or freezes after entering the 
= superuser password.
= "top" shows that no cpu is used by emacs, and i can get the control back 
= with C-g
= 
= Here is the messages left by tramp :
= 
= Loading tramp...
= Loading executable...done
= Loading tramp...done
= tramp: Opening connection for `<root>' using `su'...
= tramp: Waiting for prompts from remote shell
= tramp: Waiting 60s for prompt from remote shell
= tramp: Sending password
= Password:
= Password:.
= Password:..
= Password:...
= Password:....
= Password:.....
= Password:......
= Password:.......
= tramp-process-actions: Login failed
= 
= I remember recent considerations about a bad behavior of emacs on osx
= and communication with sub-processes. But i wasn't able to find them again.
= Maybe it is relative to my problem ?
= 
= Sébastien Kirche
= _______________________________________________
= Help-gnu-emacs mailing list
= Help-gnu-emacs@gnu.org
= http://mail.gnu.org/mailman/listinfo/help-gnu-emacs
= 

Re: Editing a file as root

[Sébastien Kirche]

gebser@speakeasy.net writes:

> Did you try logging into the server as root from the command line...  
> i.e., without using tramp?

mmh , i am not sure to clearly understand the question.

I can actually log in as root, or su/sudoing from within my user account
(outside emacs) without any problem.

As a test i just tried the same commands from within eshell : i seems that
sudo works flawlessly, but i found that i lost the prompt when suing.
That made me think it also hangs, but in fact eshell keeps responsive with
su, it just stops displaying the prompt. It comes back after an exit to the
normal user.

Sébastien Kirche

Re: Editing a file as root

[gebser]

At 14:15 (UTC+0100) on Mon, 15 Dec 2003 Sébastien Kirche said:

= gebser@speakeasy.net writes:
= 
= > Did you try logging into the server as root from the command line...  
= > i.e., without using tramp?
= 
= mmh , i am not sure to clearly understand the question.
= 
= I can actually log in as root, or su/sudoing from within my user account
= (outside emacs) without any problem.

Yes, this is what I was asking.  I just wanted to make sure that the 
problem wasn't with the server.  For example, servers are often set up 
to disallow remote logins to the root account.  (From a security 
standpoint, this is a very good idea.)

= 
= As a test i just tried the same commands from within eshell : i seems that
= sudo works flawlessly, but i found that i lost the prompt when suing.
= That made me think it also hangs, but in fact eshell keeps responsive with
= su, it just stops displaying the prompt. It comes back after an exit to the
= normal user.
= 
= ...

Just a blind guess... perhaps tramp isn't recognizing the remote
system's prompt.  In tramp.el is said:  "Recognition of the remote shell
prompt is based on the variables `shell-prompt-pattern' and
`tramp-shell-prompt-pattern' which must be set up correctly."


hth,
ken

Re: Editing a file as root

[Micha Feigin]

On Mon, Dec 15, 2003 at 01:50:12AM +0100, David Kastrup wrote:
> Micha Feigin <michf@post.tau.ac.il> writes:
> 
> > On Sun, Dec 14, 2003 at 10:25:41PM +0100, David Kastrup wrote:
> > > Dan Anderson <dan@mathjunkies.com> writes:
> > > 
> > > > bhiker@free.fr writes:
> > > > 
> > > > > To edit a file as root, do I have to start another emacs ?
> > > > 
> > > > Start emacs under  a root shell or after suing  (or sudoing emacs) and
> > > > you'll start emacs running with root permissions.
> > > 
> > > If you have tramp installed (like the CVS Emacs has by default), you
> > > can just edit the file
> > > /su::/etc/fstab
> > > (for example), Emacs will ask you for the root password, spawn a root
> > > shell and use a pipe to it to send files back and forth transparently.
> > > 
> > > tramp is available as a separate package, too, if you don't like
> > > using developer Emacsen.
> > 
> > Actually reading the tramp documentation it would seem that the correct
> > way to do this is
> > /[su/localhost]/etc/fstab
> 
> Then you are either using an outdated tramp or XEmacs or both.
> 

its bidi emacs. Its based on the cvs version (2.3.50 iirc).

> -- 
> David Kastrup, Kriemhildstr. 15, 44793 Bochum
> _______________________________________________
> Help-gnu-emacs mailing list
> Help-gnu-emacs@gnu.org
> http://mail.gnu.org/mailman/listinfo/help-gnu-emacs
> 

Re: Editing a file as root

[kgold]

This uses ftp:

	M-x find-file <RET> /root@localhost:/etc/passwd

bhiker@free.fr writes:
> To edit a file as root, do I have to start another emacs ?
> Many thanks

-- 

Re: Editing a file as root

[Benjamin Rutt]

Micha Feigin <michf@post.tau.ac.il> writes:

>> Then you are either using an outdated tramp or XEmacs or both.
>> 
>
> its bidi emacs. Its based on the cvs version (2.3.50 iirc).

Are you sure you're reading the right Info file?  Maybe visiting the
tramp info file manually will help.  (This can be done e.g. in dired
with the 'I' command, if the cursor is on the right file).
-- 
Benjamin

Re: Editing a file as root

[Micha Feigin]

On Mon, Dec 15, 2003 at 04:57:25PM -0500, Benjamin Rutt wrote:
> Micha Feigin <michf@post.tau.ac.il> writes:
> 
> >> Then you are either using an outdated tramp or XEmacs or both.
> >> 
> >
> > its bidi emacs. Its based on the cvs version (2.3.50 iirc).
> 
> Are you sure you're reading the right Info file?  Maybe visiting the
> tramp info file manually will help.  (This can be done e.g. in dired
> with the 'I' command, if the cursor is on the right file).

I visited it manually from the command line and I also tried both
syntax types, the one in the thread didn't work as menssioned (I can
send the error message again if you want).
There is no other emacs version currently installed on my machine.
I compiled it myself from the sources though. Maybe you are using a
packaged version that provides a newer version as part of the package
and not part of emacs?

> -- 
> Benjamin
> _______________________________________________
> Help-gnu-emacs mailing list
> Help-gnu-emacs@gnu.org
> http://mail.gnu.org/mailman/listinfo/help-gnu-emacs
> 

Re: Editing a file as root

[Benjamin Rutt]

Micha Feigin <michf@post.tau.ac.il> writes:

> I visited it manually from the command line and I also tried both
> syntax types, the one in the thread didn't work as menssioned (I can
> send the error message again if you want).
> There is no other emacs version currently installed on my machine.
> I compiled it myself from the sources though. 

Then look at the sources you compiled from.  There should be a
tramp.texi that contains the syntax.

> Maybe you are using a packaged version that provides a newer version
> as part of the package and not part of emacs?

Me?  I am using cvs emacs, which contains tramp.  I don't use tramp as
an external package anymore, once it was included in emacs cvs.
-- 
Benjamin

Re: Editing a file as root

[Sébastien Kirche]

gebser@speakeasy.net writes:

> Yes, this is what I was asking.  I just wanted to make sure that the 
> problem wasn't with the server.  For example, servers are often set up 
> to disallow remote logins to the root account.  (From a security 
> standpoint, this is a very good idea.)

Well the "server" is actually the same local machine. So I guess that
even if remote login is disabled (not sure it is) it should not
interfere with local login from within emacs. 
Or do i misunderstood and the /su::/some/path acts as a rlogin even on
local system ?

>
> Just a blind guess... perhaps tramp isn't recognizing the remote
> system's prompt.  In tramp.el is said:  "Recognition of the remote shell
> prompt is based on the variables `shell-prompt-pattern' and
> `tramp-shell-prompt-pattern' which must be set up correctly."

I will check for that.


Regards,
Sébastien Kirche

Re: Editing a file as root

[gebser]

At 11:07 (UTC+0100) on Wed, 17 Dec 2003 Sébastien Kirche said:

= gebser@speakeasy.net writes:
= 
= > Yes, this is what I was asking.  I just wanted to make sure that the 
= > problem wasn't with the server.  For example, servers are often set up 
= > to disallow remote logins to the root account.  (From a security 
= > standpoint, this is a very good idea.)
= 
= Well the "server" is actually the same local machine. So I guess that
= even if remote login is disabled (not sure it is) it should not
= interfere with local login from within emacs. 
= Or do i misunderstood and the /su::/some/path acts as a rlogin even on
= local system ?
= 
= ...

I guess the local/remote paradigm can be confusing in this case, so we
should speak in terms of client/server.  So, yes, if the server is
configured to disallow root logins, then you won't be able to log in as
root, even if the client and server are one the same physical machine.  
So check out the server configuration to see if this is the case.  And
as said before, the definition of the prompt string might be the problem
also.


hth,
ken

Re: Editing a file as root

[Piet van Oostrum]

>>>>> sebastien.kirche.no@spam.free.fr ( Sébastien Kirche) (SK) wrote:

SK> On my system (Mac OSX 10.2.8), emacs fails or freezes after entering the 
SK> superuser password.
SK> "top" shows that no cpu is used by emacs, and i can get the control back 
SK> with C-g

I use the following entry in tramp-default-method-alist:

 ("\\`nono\\'" ".*" "sudo")

(nono is the name of my computer), and then I enter /nono:/filename
This works.
-- 
Piet van Oostrum <piet@cs.uu.nl>
URL: http://www.cs.uu.nl/~piet [PGP]
Private email: P.van.Oostrum@hccnet.nl

Re: Editing a file as root

[Kai Grossjohann]

Micha Feigin <michf@post.tau.ac.il> writes:

> its bidi emacs. Its based on the cvs version (2.3.50 iirc).

I guess your Tramp is too old.  Note that a version like 2.95 is old,
whereas 2.0.38 is the current one.

I apologize for the confusion resulting from the numbering change.
2.95 was the RCS/CVS version number of the tramp.el file; this doesn't
make sense for packages comprising multiple files.

Kai

Re: Editing a file as root

[Kai Grossjohann]

sebastien.kirche.no@spam.free.fr ( Sébastien Kirche) writes:

> I remember recent considerations about a bad behavior of emacs on osx
> and communication with sub-processes. But i wasn't able to find them again.
> Maybe it is relative to my problem ?

The variable is process-connection-type.  Setting it to t makes Tramp
work, I believe, but could cause problems elsewhere.  You could try it
our for yourself -- if something else breaks then you know where to
look.

It may work to use the sshx method instead of ssh.  (Of course, that
is not an option with sudo.  Hm.  In principle, sudo could be changed
in a similar way.)

It may also work to use a method similar to sshx which invokes "bash
-i" instead of /bin/sh.

Kai

Re: Editing a file as root

[Kai Grossjohann]

sebastien.kirche.no@spam.free.fr ( Sébastien Kirche) writes:

> As a test i just tried the same commands from within eshell : i
> seems that sudo works flawlessly, but i found that i lost the prompt
> when suing.

eshell is not a real shell.  It is just elisp code.  So eshell uses
magic to recognize prompts: it prints them itself, so it knows what is
a prompt.  For su/sudo, the program prints a prompt, so eshell doesn't
recognize those as prompts.

"sudo bash -i" might give you a prompt from within eshell.  Not that
eshell will recognize it, but at least you can see it.

Use "cd" to have eshell cooperate with Tramp.

Kai

Re: Editing a file as root

[Kai Grossjohann]

sebastien.kirche.no@spam.free.fr ( Sébastien Kirche) writes:

> Well the "server" is actually the same local machine. So I guess that
> even if remote login is disabled (not sure it is) it should not
> interfere with local login from within emacs. 

Yes, but for a different reason.

> Or do i misunderstood and the /su::/some/path acts as a rlogin even on
> local system ?

No, /su::/some/path invokes the su program.  It does not involve
rlogin (nor ssh) at all.  So even if those are configured to say no,
then su might still let you in.

Kai

Re: Editing a file as root

[Kevin Rodgers]

Kai Grossjohann wrote:
 > sebastien.kirche.no@spam.free.fr ( Se'bastien Kirche) writes:
 >>I remember recent considerations about a bad behavior of emacs on osx
 >>and communication with sub-processes. But i wasn't able to find them again.
 >>Maybe it is relative to my problem ?
 >
 > The variable is process-connection-type.  Setting it to t makes Tramp
 > work, I believe, but could cause problems elsewhere.  You could try it
 > our for yourself -- if something else breaks then you know where to
 > look.

Does tramp provide a hook where Se'bastien could do

	(set (make-local-variable 'process-connection-type) t)

-- 
Kevin Rodgers

Re: Editing a file as root

[Kai Grossjohann]

Kevin Rodgers <ihs_4664@yahoo.com> writes:

> Does tramp provide a hook where Se'bastien could do
>
> 	(set (make-local-variable 'process-connection-type) t)

Hm.  Since it is used when start-process is called, then maybe I
should just provide a tramp-process-connection-type variable to
tweak...  Does anybody here want to submit a patch?  ;-)

Hm...

Maybe it is better to use a tramp-init-buffer function which invokes a
hook for users to tweak.  Hm.

Kai

Re: Editing a file as root

[Piet van Oostrum]

>>>>> Kai Grossjohann <kai@emptydomain.de> (KG) wrote:

KG> Kevin Rodgers <ihs_4664@yahoo.com> writes:
>> Does tramp provide a hook where Se'bastien could do
>> 
>> (set (make-local-variable 'process-connection-type) t)

KG> Hm.  Since it is used when start-process is called, then maybe I
KG> should just provide a tramp-process-connection-type variable to
KG> tweak...  Does anybody here want to submit a patch?  ;-)

I think inside tramp process-connection-type should always be set to t (or
'pty) 
I have advised tramp myself to get this:

(defadvice tramp-maybe-open-connection 
  (around set-process-connection-type)
  "Set process-connection-type to pty."
  (let ((process-connection-type 'pty))
    ad-do-it))
(ad-activate 'tramp-maybe-open-connection)

-- 
Piet van Oostrum <piet@cs.uu.nl>
URL: http://www.cs.uu.nl/~piet [PGP]
Private email: P.van.Oostrum@hccnet.nl

Re: Editing a file as root

[Kai Grossjohann]

Piet van Oostrum <piet@cs.uu.nl> writes:

> (defadvice tramp-maybe-open-connection 
>   (around set-process-connection-type)
>   "Set process-connection-type to pty."
>   (let ((process-connection-type 'pty))
>     ad-do-it))
> (ad-activate 'tramp-maybe-open-connection)

Cool.  I've now added code in tramp-maybe-open-connection to do this.
I hope it works.  Will commit when Savannah is back up.

Kai