Re: Help needed with using gnomevfs/gvfs

[Alexander Larsson <alexl redhat com>]

On Fri, 2009-04-24 at 13:07 +0200, Andreas Heinlein wrote:
> Alexander Larsson schrieb:
> > On Thu, 2009-04-23 at 10:10 +0200, Andreas Heinlein wrote:
> >   
> >> Hello,
> >>
> >> I need to write a small app which will catch volume mounts and unmounts
> >> as well as drive insertions/removal.
> >>
> >> I have written a Perl daemon for that, which hooks to the signals
> >> "drive-connected", "drive-disconnected", "volume-mounted" and
> >> "volume-pre-unmount" of a Gnome2::VFS::VolumeMonitor object. Getting
> >> "volume-mounted" or the disk signals works just fine, but I never get
> >> "volume-pre-unmount".
> >>
> >> I have no idea why, I already asked on the gtk2-perl mailing list but
> >> got no answer. In addition, I noticed that I am not getting
> >> "drive-connected" any more und Ubuntu Jaunty when the drive in question
> >> contains no recognized file system. This is bad because one use for this
> >> app is to auto-mount TrueCrypt encrypted volumes.
> >>
> >> I suspect this has to do with deprecation of GnomeVFS, but Python and
> >> Perl (the languages I know best) bindings for GVFS seem to not exist or
> >> are badly documented.
> >>
> >> Can anyone help me with this?
> >>     
> >
> > You only get volume-pre-unmount when unmounting via gnome-vfs. And
> > unfortunately, everything in the desktop now unmounts via gio, so you
> > need to use that to get this.
> >
> > GVfs has no bindings, because it doesn't have an API, its purely an
> > extension of glib. All the API is in gio (in glib), which is availible
> > at least in the python bindings.
> >
> >   
> Thanks for your help. I found out how to get a GVolumeMonitor reference
> with Python, but the situation is now even worse. I tried connecting to
> all signals of GVolumeMonitor, but this time I get only "mount-added"
> and "mount-removed". Still no pre-unmount, and no drive-(dis)connected
> (I have yet to find out what "volume-(dis)connected" means here). I
> managed to get the "unmounted" signal of a GMount returned by above
> signals, but that's too late; I need to be able to write to the
> filesystem being unmounted.

Pre-unmount was actually only implemented very recently, so you need
gnome 2.26.

> Also, I noticed that the output of e.g. get_mounts() in my app does
> never change. I.e. this code snippet:
> 
> #!/usr/bin/python
> import gio, time
> while True:
>     print gio.volume_monitor_get().get_mounts()
>     time.sleep(1)
> 
> will always show the state when it was invoked, but will never display
> new mounts and keep displaying mount which where removed in the meantime.

Yes, for this to work you must be running the glib mainloop.