Python: rather than permission denied, can you get an OS specific password challenge?

BrianK · 08-25-2011, 07:49 PM

In my python script, I need to copy files from one place to another. I know that the majority of the time, the destination will require the user to sudo or be the owner of the destination dir. Rather than get a simple "permission denied" message, is there a way to get a password challenge dialog to display (assuming running X or OSX, etc) so that the user can sudo/elevate so the file(s) can be copied w/o changing permissions on the dest?

ta0kira · 08-28-2011, 03:48 PM

First off, I have to tell you I don't know python; however, you might be able to translate this from bash to python because I think the general concept applies:

Code:

source=( 'some' 'list' 'of' 'files' )
dest='/home/you/some-dir'

[ -d "$dest" ] || exit 1

if [ ! -w "$dest" ]; then
  sudo -u "$( stat -c%U "$dest" )" cp -v "${source[@]}" -t "$dest"
else
  cp -v "${source[@]}" -t "$dest"
fi

Kevin Barry

BrianK · 08-29-2011, 02:16 PM

Thanks Kevin, but what I'm after is getting an OS-specific dialog asking for a password to pop-up. For example, when I open Synaptic on Debian/Ubuntu, I get asked for a password. The same thing often happens for update manager or something of the sort. If, in OSX, I try to copy a file (with the finder) from my homedir to, say, /Applications, it brings up a password dialog. I know those are already X applications, but I was hoping for some sort of way to spawn that from a python script... maybe using an os.system("cp --elevate_privileges /foo /bar") or something like that.

At the end of the day, I'm writing in some functionality into an existing wxPython application that will copy files from one place on a computer to another & would like to be able to do more than tell the user they don't have write permissions to the area they are trying to copy to.

Tinkster · 08-29-2011, 05:21 PM

In terms of portability the problem for Python developers would
be that they need to cater for a whole host WM/DEs, with a variety
of possible choices to get the dialog you desire. There's no generic
built in X11 way to do that, they'll be usinge kdesu, kdesudo, the
gnome equivalents, or even use something as simple as x11-ssh-askpass.

Cheers,
Tink

BrianK · 08-29-2011, 05:25 PM

I figured that might be the case.

Thanks for the replies/suggestions.

ta0kira · 08-29-2011, 09:29 PM

Quote:

Originally Posted by Tinkster

In terms of portability the problem for Python developers would
be that they need to cater for a whole host WM/DEs, with a variety
of possible choices to get the dialog you desire. There's no generic
built in X11 way to do that, they'll be usinge kdesu, kdesudo, the
gnome equivalents, or even use something as simple as x11-ssh-askpass.

Cheers,
Tink

And if none of those GUI options are available, you can always fake it with an xterm:

Code:

xterm -e 'sudo -u user cp src dest'

Kevin Barry

PS I think this is the first Programming thread I've seen with > 3,000 views that wasn't over 5 years old. It must make a good search result.

grail · 08-29-2011, 10:22 PM

Just for 2 cents of dissent, you would also need to test / know if something like sudo is actually available too

Ian John Locke II · 09-23-2011, 01:37 PM

I'm disappointed that no one suggested just running the python script with Audi in the first place... Unless of course you're programming a GUI (for some god awful reason) in which case either os or sys should have the equivalent to C's setuid. It's dangerous, but it works.

BrianK · 10-03-2011, 10:39 AM

Ian John Locke II, mind sharing some info on "Audi"? Google searching for "Audi Authentication" or "Python Audi" doesn't bring back much in the way of info that isn't related to Audi Automobiles. Do you have a link?

Ian John Locke II · 10-04-2011, 01:33 PM

Quote:

Originally Posted by BrianK

Ian John Locke II, mind sharing some info on "Audi"? Google searching for "Audi Authentication" or "Python Audi" doesn't bring back much in the way of info that isn't related to Audi Automobiles. Do you have a link?

Har, phone auto "correction". I meant simply running the script with sudo. If you were concerned about doing it across multiple machines fabric (fabfile.org iirc) and paramiko are a must. (I think paramiko relies on pycrypto so that's three things you'd need to download & install)

Sorry about the confusion.