texdef – Display the definitions of TeX commands

The (Perl) script dis­plays the def­i­ni­tion of (La)TeX com­mand se­quences/macros. Var­i­ous op­tions al­low the se­lec­tion of the used class and pack­age files and other things which can have in­flu­ence on the def­i­ni­tion (be­fore/af­ter the pream­ble, in­side an en­vi­ron­ment, …).
The script cre­ates a tem­po­rary TeX file which is then com­piled us­ing (La)TeX to find the ‘\mean­ing’ of the com­mand se­quence. The re­sult is for­mat­ted and pre­sented to the user. Length or num­ber com­mand se­quences (di­men­sions, \char…, count reg­is­ters, …) are rec­og­nized and the con­tained value is also shown (us­ing \the). Spe­cial def­i­ni­tions like pro­tected macros are also rec­og­nized and the un­der­ly­ing macros are shown as well.
The script will show plain TeX def­i­ni­tions by de­fault. LaTeX and ConTeXt are sup­ported, in­clud­ing flavours (pdf(la)tex, lua(la)tex, xe(la)tex, …). The flavour can be se­lected us­ing an com­mand line op­tion or over the script name: la­texdef will use LaTeX as de­fault, etc.