[XeTeX] Do we really need XeTeX specific paths? (was: Experiences with XeTeX on Debian Sarge and Ubuntu Edgy Eft)

[Jonathan Kew]

On 24 Oct 2006, at 6:55 pm, Ralf Stubner wrote:

> Do we really need XeTeX specific path settings? I have the impression
> that they are a constant source of errors and confusion, and I like to
> simplify stuff.

Much of this is (in my mind) an interim setup, arising because xetex  
(and its supporting files) is being installed as an add-on rather  
than integrated with the main tex/latex distribution. This will  
change soon (I hope).

>
> Let's look at the actual files installed in these directories:
>
> * .ini files:
>
> TEXMF/tex/xetex/config/xetex.ini
> TEXMF/tex/xelatex/config/xelatex.ini
>
> Like other .ini files, these should be placed in
>
> TEXMF/tex/plain/config/
> TEXMF/tex/latex/config/

And in the TL repository, that's where you'll find them.

>
> * updates to LaTeX style files (currently url.sty and xkeyval.sty):
>
> These should go somewhere below TEXMF/tex/latex/, so that other  
> engines
> together with the LaTeX format can profit from the updates.

xkeyval is included only because teTeX includes a version that is too  
old for fontspec. This will not be needed with an up-to-date base  
LaTeX installation.

url.sty is included because the version currently shipping with teTeX  
and texlive is not readable as utf-8. The changes to allow it to be  
read by xetex have no effect at all under other engines. The issue  
has been reported to the author, and I hope there will be an update  
forthcoming, at which point xetex will no longer need to provide its  
own copy.

>
> * XeLaTeX specific style files (fontspec, euenc, xltxtra, xunicode,
> xetex.def):
>
> These packages give an error message when not used with XeTeX as  
> engine.
> IMO this is better than a 'file not found' error when accidentally
> running say pdflatex on a file meant for xelatex. Hence I think
> TEXMF/tex/latex/ is better.

You shouldn't get "file not found" because of the typical $TEXMF/tex/ 
{latex,generic,}// path, which allows the entire tex subtree to be  
searched as a last resort (after tex/latex and tex/generic). So the  
xelatex subtree is primarily an organizational convenience, though it  
also makes it possible for xelatex to "prefer" different .cfg files  
to pdflatex, etc.; this may not really be needed in most cases.

>
> * Configuration files for various LaTeX packages (graphics, color,  
> crop,
> hyperref, geometry)
>
> These files should be modified such that they can distinguish between
> being loaded by XeTeX, pdfTeX, TeX, ... and incorporate the default
> behaviour from the relevant packages. I think this is one of the  
> things
> that has to be done for getting XeTeX into TeX Live.

I believe most of them, at least, are already "safe" for use under  
any engine, but this needs to be checked as part of the TL  
integration work.

JK