[texworks] SCRIPTING: on linux say Ubuntu - script write priveledges

[Stefan Löffler]

Hi,

On 2011-05-24 09:08, Paul A Norman wrote:
>
> <ramblings>
>
> Would look to putting current Xp systems into sandboxed VBoxes under
> say Ubuntu when the time for Xp expires...

The time for XP has expired, hasn't it? (mainstream support ended in
2009, anyway)
FWIW, running XP under VirtualBox on Ubuntu works. Whether it works well
depends on your system, processor, and its ability for virtualization.
On my PC at work, things slow down horribly when running VBox, on my
laptop at home it works quite well (though I still wouldn't try to play
games on it ;)).

> </ramblings>
>
>>> After setting the ppa required
>>> https://launchpad.net/~texworks/+archive/ppa, Using sudo apt-get
>>> install stuff to setup TeXworks 0.5 ver813 (works really nicely), when
>>> a user runs a Tw script from TeXworks, can the script automatically
>>> (if Tw's preferences permissions are already set) write/read to
>>> subdirectories of the Tw script's own directory?
>> Yes, that should be possible in the same way as on the other OSs by default.
>> <random rambling>
>> Of course, the user must have read/write permissions to the files and
>> directories in question. This is required by Linux independent of Tw.
>> Since, by default, the resources are put under the user's home
>> directory, this shouldn't be a problem.
> Ok, please see point below. This is leading to what I am thinking about.
>
>>  Note, though, that resources
>> provided by Tw typically are installed read-only (on my machine,
>> anyway). I haven't investigated this yet, as it is not a problem for me
>> (any noone else has complained yet ;)) - you wouldn't want to overwrite
>> "official" files, anyway, would you?
>> </random rambling>
>>
>>> Also I have found that when logged in under the user name established
>>> during Ubuntu install, running TeXworks form a console produces a
>>> version that shows the TeXworks menu items in the new Unity top frame,
>>> however if I start TeXworks as sudo TeXworks I get a more classical
>>> looking (similar to Windows) appearance of TeXworks layout with the Tw
>>> menus in the program's own frame. What should I make of that please?
>> Interesting, I haven't noticed this before, but I can confirm it. Is
>> there a special reason to run Tw with sudo (normally, one wouldn't; btw,
>> GUI applications should be run with gksudo, but this doesn't change the
>> effect)?
>> I tried with other Qt/KDE applications as well (kcalc, kdenlive), and
>> they exhibit the same problem. So I'd say this is a problem with the
>> interaction Qt-unity as the root user. Did you try creating a new user
>> (different from the one created during installation) and running Tw or
>> other Qt/KDE apps there?

I tried the new user thing myself, it seems the behavior is exactly the
same as with the "default" (i.e., created during installation) user. So,
this indeed seems to be a Qt/unity bug. Since you found it, I leave it
to you to report it (try `ubuntu-bug unity` on the command line) if you
want to.

> Well this is where I am at...
>
> Using a new user, would require that the scripts were copied to their
> (new) home directory?

Yes. The bundled scripts (and other resources) are installed
automatically when the user runs Tw for the first time. But other
scripts would need to be copied/linked manually.

> Or what happens to Linux file permissions, or does TeXworks install as
> it's own group with linux file permissions to everyone or as its in
> HOME/USER obviously then scripts are limited to that User?

Tw should install scripts with the permissions of the user it was run by
(i.e., either the current user or root). It seems files are created with
read permission for everyone, write and execute permissions for no one.
User and group are set to the ones of the user that ran Tw.

> That's when/why I started looking at sudo - thanks for note on gksudo,
> it floats back into memory dimmly :)

There's really no need for that, as everyone gets the same permissions.
In fact, it will probably create the files with user and group root,
which means that it's harder to change permissions (e.g., if you want to
change a script).

> (I like Jamie's comment when talking about gksudo , "...Man pages are
> extremely useful for this kind of thing, a lot of the time
> they seem to contain gibberish or language that only experienced
> unix/linux sysadmins can understand, but this really just depends on
> the author. ...
> https://lists.ubuntu.com/archives/ubuntu-studio-users/2007-September/000472.html)

How true...
In fact, I don't understand the differences myself, I just read about it
somewhere and thought that there probably is a (good?) reason for it ;).

> In some educational situations say, and  in other shared
> circumstances, does each User maintain their own Script folder (yes),
> or/and can an administrator set up a central Tw script repository on
> each PC, or preferably even for a whole local network?

Partly global setups are not supported at the moment. Basically, this is
because there's no waterproof concept yet how to "merge" global and
local settings. For instance, how to distinguish (easily) between a
sys-admin wanting to override user settings (e.g., for security reasons)
and one wanting to provide sensible defaults for the user to customize?

That said, the texworks-setup.ini approach still works (you can put it
alongside the texworks binary; in the ppa install, this would be in
/usr/bin/). This way, all users could use the same resources (preferably
not in /usr/bin, but instead maybe in /etc/texworks or /var/texworks or
something of the sort).

HTH
Stefan