On 12/07/2011 06:01 PM, Yasha Karant wrote:
> It seems the default PDF reader for EL 6 is evince. In which file(s) is
> this set so that I can select a different default application? If any of
> these files are not plain ASCII text, but require a special application
> to read/write the file, which such application(s)?

This is a desktop/window manager specific setting. If you install KDE 
and Gnome you can have each prefer a different application for a 
specific MIME type (in this case PDF).

Evince is free, safe, and is the default reader nearly everywhere for 
Linux. Adobe Reader/Acrobat have some pretty large security issues 
(hopefully well tacked down by SELinux, but hope != security_plan).

PDFs are not ASCII text. PDF is an extension of the PostScript language 
that printers speak which describe how a document should look and what 
it should do, which includes a description of text to include, but this 
is not restricted to ASCII characters by any means. PDF adds to PS in 
ways that let a document do a few things dynamically based on 
environment (like switch date formats around), include user input fields 
(and change based on what is input/selected), accept digital signatures, 
etc. Many static PDFs passed about in business are nothing more than 
scans of text, which mean they are pictures of a page which contains 
text, not the actual text itself. It is quite common to receive 
documents in mass business mailings which are just a giant jpeg image 
pasted to a standard page-size background which is called a PDF because 
the scanner/digital sender formatted it that way -- but its not actually 
text and you can't copy/paste it (this is also why a PDF exported from 
OpenOffice will be often measured in kilobytes, while a scan of a 
printout of the same thing can easily be a few megabytes/page at high 
resolution + color).

For Gnome2 you can find settings for nearly everything in gconf editor. 
This is usually found under Applications > System Tools > Configuration 
Editor if you've installed it, I believe.

I personally prefer Evince for nearly everything and use it as much as 
possible. For digital signatures which must conform to Adobe's way of 
doing things, however, I open documents in Acrobat Reader -- but I do 
not set the default PDF reader to Acrobat Reader. In Gnome you can just 
right-click, and select "Open With >" and pick the PDF capable software 
you want. I also use Xournal a lot for PDF markup and passing notes 
around, so this is another program I access by right-clicking quite 
frequently on PDF files -- but my default is still happily set to Evince 
(and you'll find it is by far the fastest loading PDF/PS file reader 
available right now).