On Wed, May 6, 2009 at 11:49 AM, Rex Dieter rdieter@math.unl.edu wrote:
Paul Johnson wrote:
In Centos 5.3, a bad problem has surfaced in user land. We want to use either Evince or Adobe acroread as the pdf view, but the update of kdegraphics has somehow screwed up these systems so that the odious, horrible, awful pdf viewer kghostview is used.
It's most likely Acrobat Reader that f#$#$#d up here. It mucks with system copies of mimetypes, etc...
My guess is that kdegraphics update simply replaced the muck'd system copies with known good ones.
Now, opening pdf's from where is causing problems? Say, opening in nautilus, a webbrowser, what?
-- Rex
Same result in opening pdf from nautilus or LyX (via pdflatex). kghostview refuses to open the pdf file, saying its type is application/octet-stream. evince or acroread can open same without trouble. I have not bothered with this because I'm not using kde anymore, but the kdegraphics update with Centos-5.3 caused this by installing the program and re-configuring (explanation next).
I've tracked down the problem, though, so I can stop kghostview from being invoked.
When RPMS install, they often have a post script call to execute "update-desktop-database" which scans the desktop files under /usr/share/applications and it builds /usr/share/applications/mimeinfo.cache.
To my surprise/astonishment, the update-desktop-database function is completely undocumented, not even a man page or a mention in the README file from the xdg group that provides it. To my even greater surprise, there is apparently no way to predict which programs will be at the front of the list for each mime type. The mimeinfo.cache is used by programs like nautilus to know what programs are available. update-desktop-database, for reasons I don't know, places ghostview first among pdf opener programs.
More and more programs are relying on the "xdg-open" script to select viewers for files. xdg-open ends up scanning for the desktop framework in use, in my case Gnome, and then it passes off the pdf file to the program gnome-open, which is supposed to check for "defaults.list" in the user's config and in the system at /usr/share/applications. The mimeinfo.cache file is not supposed to be dominant setting here because the preferred viewer is supposed to be specified in defaults.list. We have AdobeReader.desktop specified there.
However, when the config in defaults.list is broken, then xdg-open (hence gnome-open) don't know what to do, and they consult mimeinfo.cache and they take the first program listed.
Our config was broken because Adobe was installed incorrectly. The RPM that installed AdobeReader did not copy AdobeReader.desktop into /usr/share/applications. As a result, when the user tries to configure "xdg-open" (via xdg-mime) or use "gnome-open", both try to use AdobeReader.desktop, and fail, and then they fall back to use the things in /usr/share/applications/mimeinfo.cache. One can just copy AdobeReader.desktop from /opt/Adobe/... into /usr/share/applications to fix this. To be fancier, one can run "
To protect my systems from ever using kghostview, I ended up deleting the Mime line in all of the relevant desktop files in /usr/share/applicaitons/kde. After that, "update-desktop-database" can be called and kghostview is never listed as a pdf opener.