[gentoo-dev] showing file diffs as root

[gentoo-dev] showing file diffs as root

[Christopher Harvey]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello gentoo-dev,

I'm working on an app for GSoC that needs to show a diff of two files
to the user. Right now I've just been calling meld from the python
os.system call. I tried running my application as root to show diffs
of system files that belong to root. I got this error:

Traceback (most recent call last):
  File "/usr/bin/meld", line 90, in <module>
    meldapp.main()
  File "/usr/lib/meld/meldapp.py", line 982, in main
    app = MeldApp()
  File "/usr/lib/meld/meldapp.py", line 562, in __init__
    self.prefs = MeldPreferences()
  File "/usr/lib/meld/meldapp.py", line 435, in __init__
    super(MeldPreferences, self).__init__("/apps/meld", self.defaults)
  File "/usr/lib/meld/prefs.py", line 92, in __init__
    self._gconf.add_dir(rootkey, gconf.CLIENT_PRELOAD_NONE)
glib.GError: Failed to contact configuration server; some possible
causes are that you need to enable TCP/IP networking for ORBit, or you
have stale NFS locks due to a system crash. See
http://projects.gnome.org/gconf/ for information. (Details -  1:
Failed to get connection to session: Did not receive a reply. Possible
causes include: the remote application did not send a reply, the
message bus security policy blocked the reply, the reply timeout
expired, or the network connection was broken.)

I haven't looked into why this is happening very much because calling
os.system("meld file1 file2 &") in python is putting up so many red
flags in my head it's not funny. If anybody could tell me the proper
gentoo/linux/python way to present a root level diff to a user running
a program through su or sudo I'd really appreciate the help.

thanks,
Chris

- -- 
My GnuPGP key at:
www.basementcode.com/public_key.txt
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Re: [gentoo-dev] showing file diffs as root

[Domen Kožar]

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Hey!

Maybe I am missing something, but why not use difflib and pygments on
top of that?

Cheers, Domen

On Sun, 2010-05-30 at 10:59 -0400, Christopher Harvey wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hello gentoo-dev,
> 
> I'm working on an app for GSoC that needs to show a diff of two files
> to the user. Right now I've just been calling meld from the python
> os.system call. I tried running my application as root to show diffs
> of system files that belong to root. I got this error:
> 
> Traceback (most recent call last):
>   File "/usr/bin/meld", line 90, in <module>
>     meldapp.main()
>   File "/usr/lib/meld/meldapp.py", line 982, in main
>     app = MeldApp()
>   File "/usr/lib/meld/meldapp.py", line 562, in __init__
>     self.prefs = MeldPreferences()
>   File "/usr/lib/meld/meldapp.py", line 435, in __init__
>     super(MeldPreferences, self).__init__("/apps/meld", self.defaults)
>   File "/usr/lib/meld/prefs.py", line 92, in __init__
>     self._gconf.add_dir(rootkey, gconf.CLIENT_PRELOAD_NONE)
> glib.GError: Failed to contact configuration server; some possible
> causes are that you need to enable TCP/IP networking for ORBit, or you
> have stale NFS locks due to a system crash. See
> http://projects.gnome.org/gconf/ for information. (Details -  1:
> Failed to get connection to session: Did not receive a reply. Possible
> causes include: the remote application did not send a reply, the
> message bus security policy blocked the reply, the reply timeout
> expired, or the network connection was broken.)
> 
> I haven't looked into why this is happening very much because calling
> os.system("meld file1 file2 &") in python is putting up so many red
> flags in my head it's not funny. If anybody could tell me the proper
> gentoo/linux/python way to present a root level diff to a user running
> a program through su or sudo I'd really appreciate the help.
> 
> thanks,
> Chris
> 
> - -- 
> My GnuPGP key at:
> www.basementcode.com/public_key.txt
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> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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> -----END PGP SIGNATURE-----
> 
> 


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Re: [gentoo-dev] showing file diffs as root

[Christopher Harvey]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 05/30/10 11:21, Domen Kožar wrote:
> Hey!
> 
> Maybe I am missing something, but why not use difflib and pygments on
> top of that?
> 
> Cheers, Domen
> 

That's a good option.
Pros:
Can easily integrate the diff viewer into my application.

Cons:
Doesn't seem to be a way to interactively merge files (not a big deal
for me)

As for generating the diff is it ok to use difflib to generate the diff
text? I hear there is a diff environment variable..(but I can't seem to
find it now) should I use that instead?

- -- 
My GnuPGP key at:
www.basementcode.com/public_key.txt
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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

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Re: [gentoo-dev] showing file diffs as root

[Domen Kožar]

[-- Attachment #1: Type: text/plain, Size: 1553 bytes --]

difflib is one of the best Python libraries out there. It does it's job
perfectly.

difflib can generate diff in text, any it's very pluggable (go through
documentation, you will see)

On Sun, 2010-05-30 at 11:27 -0400, Christopher Harvey wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On 05/30/10 11:21, Domen Kožar wrote:
> > Hey!
> > 
> > Maybe I am missing something, but why not use difflib and pygments on
> > top of that?
> > 
> > Cheers, Domen
> > 
> 
> That's a good option.
> Pros:
> Can easily integrate the diff viewer into my application.
> 
> Cons:
> Doesn't seem to be a way to interactively merge files (not a big deal
> for me)
> 
> As for generating the diff is it ok to use difflib to generate the diff
> text? I hear there is a diff environment variable..(but I can't seem to
> find it now) should I use that instead?
> 
> - -- 
> My GnuPGP key at:
> www.basementcode.com/public_key.txt
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2.0.14 (GNU/Linux)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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Re: [gentoo-dev] showing file diffs as root

[Michał Górny]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Sun, 30 May 2010 11:27:41 -0400
Christopher Harvey <chris@basementcode.com> wrote:

> As for generating the diff is it ok to use difflib to generate the
> diff text? I hear there is a diff environment variable..(but I can't
> seem to find it now) should I use that instead?

If I correctly understand what you're referring to, that variable is
useful if you just need to present the diff to the user in the format
preferred by him -- he could then choose an alternate diffing program,
offering another output format.

If you need to parse the differences, that's not an option for you as
the diffing program chosen by user might use any freeform output
format, making it unparseable. Thus, in that case difflib is the solu-
tion you're looking for -- it is prepared to provide the differences
in a way suitable for program use.


- -- 
Best regards,
Michał Górny

<http://mgorny.alt.pl>
<xmpp:mgorny@jabber.ru>
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Re: [gentoo-dev] showing file diffs as root

[Sebastian Pipping]

On 05/30/10 16:59, Christopher Harvey wrote:
> [..] because calling
> os.system("meld file1 file2 &") in python is putting up so many red
> flags in my head it's not funny. [..]

On a sidenote: the subprocess module offers better alternatives to
calling os.system:
http://docs.python.org/library/subprocess.html

Best,



Sebastian

Re: [gentoo-dev] showing file diffs as root

[Francesco R]

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why not make a temporary copy of the files with appropriate permission,
send a message the application the user originally opened to diff the files,
then apply the user modified file and cleanup the $tmpdir?

This would leave the user the possibility to choose whatever application she
want to do the merge, which is a big plus.

2010/5/30 Christopher Harvey <chris@basementcode.com>

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Hello gentoo-dev,
>
> I'm working on an app for GSoC that needs to show a diff of two files
> to the user. Right now I've just been calling meld from the python
> os.system call. I tried running my application as root to show diffs
> of system files that belong to root. I got this error:
>
> Traceback (most recent call last):
>  File "/usr/bin/meld", line 90, in <module>
>    meldapp.main()
>  File "/usr/lib/meld/meldapp.py", line 982, in main
>    app = MeldApp()
>  File "/usr/lib/meld/meldapp.py", line 562, in __init__
>    self.prefs = MeldPreferences()
>  File "/usr/lib/meld/meldapp.py", line 435, in __init__
>    super(MeldPreferences, self).__init__("/apps/meld", self.defaults)
>  File "/usr/lib/meld/prefs.py", line 92, in __init__
>    self._gconf.add_dir(rootkey, gconf.CLIENT_PRELOAD_NONE)
> glib.GError: Failed to contact configuration server; some possible
> causes are that you need to enable TCP/IP networking for ORBit, or you
> have stale NFS locks due to a system crash. See
> http://projects.gnome.org/gconf/ for information. (Details -  1:
> Failed to get connection to session: Did not receive a reply. Possible
> causes include: the remote application did not send a reply, the
> message bus security policy blocked the reply, the reply timeout
> expired, or the network connection was broken.)
>
> I haven't looked into why this is happening very much because calling
> os.system("meld file1 file2 &") in python is putting up so many red
> flags in my head it's not funny. If anybody could tell me the proper
> gentoo/linux/python way to present a root level diff to a user running
> a program through su or sudo I'd really appreciate the help.
>
> thanks,
> Chris
>
> - --
> My GnuPGP key at:
> www.basementcode.com/public_key.txt
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v2.0.14 (GNU/Linux)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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>
>
>

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Re: [gentoo-dev] showing file diffs as root

[Gilles Dartiguelongue]

Le dimanche 30 mai 2010 à 10:59 -0400, Christopher Harvey a écrit :
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hello gentoo-dev,
> 
> I'm working on an app for GSoC that needs to show a diff of two files
> to the user. Right now I've just been calling meld from the python
> os.system call. I tried running my application as root to show diffs
> of system files that belong to root. I got this error:
> 
> Traceback (most recent call last):
>   File "/usr/bin/meld", line 90, in <module>
>     meldapp.main()
>   File "/usr/lib/meld/meldapp.py", line 982, in main
>     app = MeldApp()
>   File "/usr/lib/meld/meldapp.py", line 562, in __init__
>     self.prefs = MeldPreferences()
>   File "/usr/lib/meld/meldapp.py", line 435, in __init__
>     super(MeldPreferences, self).__init__("/apps/meld", self.defaults)
>   File "/usr/lib/meld/prefs.py", line 92, in __init__
>     self._gconf.add_dir(rootkey, gconf.CLIENT_PRELOAD_NONE)
> glib.GError: Failed to contact configuration server; some possible
> causes are that you need to enable TCP/IP networking for ORBit, or you
> have stale NFS locks due to a system crash. See
> http://projects.gnome.org/gconf/ for information. (Details -  1:
> Failed to get connection to session: Did not receive a reply. Possible
> causes include: the remote application did not send a reply, the
> message bus security policy blocked the reply, the reply timeout
> expired, or the network connection was broken.)
> 
> I haven't looked into why this is happening very much

https://bugs.gentoo.org/show_bug.cgi?id=286577
https://bugs.gentoo.org/show_bug.cgi?id=302597

and probably a couple more duplicates.

-- 
Gilles Dartiguelongue <eva@gentoo.org>
Gentoo