Imagine this but with pretty colors:
$ latexdef def @newcommand author box parskip thanks begin bedgin
\def is primitive.
\@newcommand = #1[#2] -> \kernel@ifnextchar [{\@xargdef #1[#2]}{\@argdef #1[#2]}
\author = #1 -> \gdef \@author {#1}
\box is primitive.
\parskip is primitive.
\thanks = #1 -> \footnotemark \protected@xdef \@thanks {\@thanks \protect \footnotetext [\the \c@footnote ]{#1}}
\begin = #1 -> \@ifundefined {#1}{\def \reserved@a {\@latex@error {Environment #1 undefined}\@eha }}{\def \reserved@a {\def \@currenvir {#1}\edef \@currenvline {\on@line }\csname #1\endcsname }}\@ignorefalse \begingroup \@endpefalse \reserved@a
Further:
$ latexdef --help
latexdef 0.1.0
Rebecca Turner <rbt@sent.as>
Prints definitions of LaTeX macros.
USAGE:
latexdef [FLAGS] [OPTIONS] <COMMAND>... --documentclass <CLASS> --engine <ENGINE>
FLAGS:
-e, --expl3 Enable LaTeX3e features with the expl3 package
--math Load common math packages (amsmath, amssymb, amsthm, mathtools)
-h, --help Prints help information
-V, --version Prints version information
OPTIONS:
--documentclass <CLASS> Document class to use [default: article]
--engine <ENGINE> TeX engine to run. [default: latex]
-p, --packages <PACKAGE>... Packages to load
ARGS:
<COMMAND>... Commands to show definitions of
Install with:
cargo install latexdef