LuaLaTeX Variable Expansion

Question

I've run into an issue with variable expansion in the different distributions of LuaLaTeX (chiefly MikTeX and TeXLive). In TeXLive (both 2014 and 2016), I can use the following to reference my home directory:

\newcommand{\home}{$HOME}

and subsequently have commands like the following to allow me to reference both my Windows (work) and Linux (home) filesystems.

\graphicspath{{\home/LaTeX/logos/}{\home/LaTeX/signature}}

The problem that I'm running into is that I can't figure out how to make the MikTeX version of LuaLaTeX expand the path variable.

I've tried just about every combination of

\newcommand{\home}{${HOME}}
\newcommand{\home}{${$HOME}}
\newcommand{\home}{\%HOME\%}
\newcommand{\home}{${\%HOME\%}}

and

miktex-lualatex --enable-write18
miktex-lualatex -enable-write18
miktex-lualatex --shell-escape
miktex-lualatex -shell-escape

but nothing I do allows me to find the font I'm trying to reference. I get varying versions of

luaotfload | db : Reload initiated (formats: otf,ttf,ttc); reason: "File not found: ${$HOME}/LaTeX/fonts/

depending on what I try to make the combo of options above.

If someone could shed some light on what I'm missing or perhaps present a better solution that what I have been doing, it would be greatly appreciated. I compile with both pdfLaTeX and LuaLaTeX depending on whether or not I need the OTF fonts.

score 2 · Answer 1 · answered Jul 21 '16 at 16:15

2

I can't really believe that $HOME works, but on windows you can use something like this (to avoid problems with the backslash in pathes, one should print the path with another catcode table):

\documentclass{article}
%
\usepackage{graphicx}


%log all values of os.env:

\directlua{for k, v in pairs( os.env ) do
   texio.write_nl ("key: "..k .. " value: ".. v)
end}

\begin{document}
\includegraphics{\directlua{tex.print(-2,os.getenv("USERPROFILE"))}/Pictures/babel.png}
\end{document}

answered Jul 21 '16 at 16:15

Ulrike Fischer

327,261

This solves the problem for miktex-lualatex and the texlive version, but leaves miktex-pdflatex in a lurch. It also breaks my Linux lualatex. – aepksbuck Jul 21 '16 at 16:30
Your question didn't mention pdflatex, it also didn't mention linux. Perhaps you can use a variant of this solution http://tex.stackexchange.com/a/62032/2388 – Ulrike Fischer Jul 21 '16 at 16:37
My question did initially mention Linux and I updated it to mention pdflatex, which I hadn't gotten to yet. Sorry for the confusion. – aepksbuck Jul 21 '16 at 16:58

score 2 · Accepted Answer · answered Jul 21 '16 at 16:48

2

If you pass \newcommand{\home}{$HOME} in the command line, then the shell will interpret the variable, but in a TeX file it would not work.

You can use catchfile and kpsewhich that, I believe, also works in MiKTeX.

\documentclass{article}
\usepackage{catchfile}

\CatchFileEdef{\home}{|"kpsewhich -var-value=HOME"}{\endlinechar=-1 }

\begin{document}

\texttt{\home}

\end{document}

Real data has been masked off:

If you're afraid of backslashes, do

\CatchFileEdef{\home}{|"kpsewhich -var-value=HOME"}{%
  \endlinechar=-1
  \catcode`\\=12
}

answered Jul 21 '16 at 16:48

egreg

1,121,712

With miktex one has to use --enable-pipes. – Ulrike Fischer Jul 21 '16 at 17:00
This seems to work across everything that I want it to.
I needed to add --enable-pipes for miktex-pdflatex but not for miktex-lualatex.
– aepksbuck Jul 21 '16 at 17:10

michal.h21 · Answer 3 · 2016-07-21T17:09:19.303

1

There is os.getenv function provided by Lua, so I would use that:

\documentclass{article}

\newcommand\home{\directlua{tex.print(-2,os.getenv("HOME"))}}

\begin{document}

this is home: \home

\end{document}

edited Jul 21 '16 at 17:09

answered Jul 21 '16 at 16:11

michal.h21

50,697

This works for Linux, but has issues on Windows with backslashes. – aepksbuck Jul 21 '16 at 16:31

LuaLaTeX Variable Expansion

3 Answers3