texdef -- Show definitions of TeX commands

This perl script shows the definition of (La)TeX commands in a similar way as `\show`.


Version 1.0 -- 2011/03/05
Copyright (C) 2011  Martin Scharrer <martin@scharrer-online.de>
This program comes with ABSOLUTELY NO WARRANTY;
This is free software, and you are welcome to redistribute it under certain conditions;

Usage:
  texdef   [options] commandname [commandname ...]
  latexdef [options] commandname [commandname ...]

Other program names are possible. See the 'tex' option.  Command names do not need to start with `\`.

Options:
  --tex <flv>, -t <flv> : Use given flavour of TeX: 'tex', 'latex', 'context'.
                          Variations of 'tex' and 'latex', like 'luatex', 'lualatex', 'xetex', 'xelatex' are supported.
                          The default is given by the used program name: 'texdef' -> 'tex', 'latexdef' -> 'latex', etc.
  --value, -v           : Show value of command instead (i.e. \the\command).
  --preamble, -P        : Show definition of the command inside the preamble.
  --beforeclass, -B     : Show definition of the command before \documentclass.
  --package <pkg>, -p <pkg>     : (M) Load given tex-file, package or module depending on whether '*tex', '*latex'
                                  or 'context' is used. For LaTeX the <pkg> can start with `[<options>]` and end 
                                  with `<pkgname>` or `{<pkgname>}`.
  --class <class>, -c <class>   : (LaTeX only) Load given class instead of default ('article').
                                  The <class> can start with `[<classs options>]` and end 
                                  with `<classname>` or `{<classname>}`.
  --environment <env>, -p <env> : (M) Show definition inside the given environment <env>.
  --othercode <code>, -o <code> : (M) Add other code into the preamble before the definition is shown.
                                  This can be used to e.g. load PGF/TikZ libraries.
  --before <code>, -b <code>    : (M) Place <code> before definition is shown.
                                  The <code> can be arbitray TeX code and doesn't need be be balanced.
  --after  <code>, -a <code>    : (M) Place <code> after definition is shown.
                                  The <code> can be arbitray TeX code and doesn't need be be balanced.
  --help, -h                    : Print this help and quit.

 Long option can be shorten as long the are still unique.  Short options can be combined.
 If the option 'environment', 'before' and 'after' are used toegether the
 produced code will be inserted in the given order (reversed order for 'after').
 (M) = This option can be given multiple times.

Examples:
Show the definition of '\chapter' with different classes ('article' (default), 'book' and 'scrbook'):

    latexdef chapter
    latexdef -c book chapter
    latexdef -c scrbook chapter

Show value of `\textwidth` with different class options:

    latexdef -c [a4paper]{book} -v paperwidth
    latexdef -c [letter]{book}  -v paperwidth

Show definition of TikZ's '\draw' outside and inside a 'tikzpicture' environment:

    latexdef -p tikz draw
    latexdef -p tikz --env tikzpicture draw

Show definition of TikZ's '\draw' inside a node, inside a 'beamer' frame in 'handout' mode:

    latexdef -c [handout]beamer -p tikz --env frame --env tikzpicture -b '\node {' -a '};' draw