running gdb as root under emacs (24)

running gdb as root under emacs (24)

[stefan.puiu]

Hi, 

I'm working on a project that needs to run as root and was wondering if there is a way to run gdb as root from emacs. Simply trying 'M-x gdb' and then 'sudo gdb ...' does not seem to work. While googling, I found that you can use tramp to run certain commands as root (https://groups.google.com/forum/#!topic/gnu.emacs.help/fXxnXc3v-pM), so based on that I tried 'M-:' and then something like this: 

(with-temp-buffer
  (cd "/sudo::/")
  (shell-command "gdb -q"))

This doesn't seem to work interactively, however - I get a buffer that simply has "(gdb) quit" as the output and then there are some weird characters in the minibuffer. 

What would be a workable approach to achieve this? I'm using emacs24 on Ubuntu 16.04 (though I don't mind upgrading if that's what it takes). 

Thanks,
Stefan.

Re: running gdb as root under emacs (24)

[Michael Albinus]

stefan.puiu@gmail.com writes:

> Hi, 

Hi,

> What would be a workable approach to achieve this? I'm using emacs24
> on Ubuntu 16.04 (though I don't mind upgrading if that's what it
> takes).

Call "M-x gdb" from a buffer, which has a default-directory somewhere at
"/sudo::". I'm not sure whether it works with Emacs 24, but it is worth
a try.

> Thanks,
> Stefan.

Best regards, Michael.

Re: running gdb as root under emacs (24)

[stefan.puiu]

Hi Michael,

> Call "M-x gdb" from a buffer, which has a default-directory somewhere at
> "/sudo::". I'm not sure whether it works with Emacs 24, but it is worth
> a try.

Thanks for the suggestion. 
I've tried this - opened up a C file from my project in emacs, then 'M-x cd' and used '/sudo::/'. I see a '@' next to the file name in the grey bar below, and if I hover over it it says 'Current directory is: remote:/sudo...'. However, running 'M-x gdb' results in gdb running as my user. Am I missing something, or was this what you suggested? 

I tried this only on Emacs 24, the one that comes with Ubuntu. I can try a newer version, just to make sure. 

Thanks,
Stefan.

Re: running gdb as root under emacs (24)

[stefan.puiu]

> I tried this only on Emacs 24, the one that comes with Ubuntu. I can try a newer version, just to make sure. 

Hey, what do you know, this actually works on emacs 25! It asks for my password twice (once when setting the current directory, once when starting gdb), but otherwise, works OK! Thanks a lot! 

Re: running gdb as root under emacs (24)

[Michael Albinus]

stefan.puiu@gmail.com writes:

> Hey, what do you know, this actually works on emacs 25! It asks for my
> password twice (once when setting the current directory, once when
> starting gdb), but otherwise, works OK! Thanks a lot!

That's why I said I don't know the situation with Emacs 24. There were
some changes, but I didn't remember when they've arrived Emacs.

The password requests could be minimized, check the Tramp manual about.

Best regards, Michael.