LaTeXDatax

Save specified variables to a data file to be read into a LaTeX document using the accompanying package datax.sty.

using Pkg;Pkg.add("LaTeXDatax"), and install the datax package [ctan].

using LaTeXDatax, Unitful
a = 25;

@datax a b=3a c=3e8u"m/s" d="Raw string" filename:="data.tex"

\documentclass{article}
\usepackage{siunitx}
\usepackage[dataxfile=data.tex]{datax}

\begin{document}
The speed of light is \datax{c}.
\end{document}

More detailed usage information is in the docstrings of the code, run ?@datax in REPL to read them.