I would like to define a command which checks if it is executed inside a certain environment. Like this:


\newenvironment{myenv}[0]{at start}{ at end}

  % if iside a myenv
  % else
  % end





See the definition of \inner. Is an if-condition of this form possible?


LaTeX keeps the current environment in the macro \@currenvir


Another approach would be to define a global conditional that's set to true by myenv start code and to false by myenv end code. It depends mostly on what you are expecting from the myenv environment: can it appear nested inside itself?

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  • 3
    @Nickoley: Note that this doesn't work any longer when \inner is used inside another environment inside the myenv environment, e.g. \begin{myenv}\begin{center}\inner\end{center}\end{myenv}. Then \@currenvir` will be center when \inner is expanded. – Martin Scharrer May 20 '11 at 10:28
  • This does not seem to work on my end. It produces the "else" output both inside and outside a myenv environment. However, both \@currenvir and \@myenvname display the correct (and the same) output when placed inside the environment. – Danny Hansen Mar 25 '19 at 21:33
  • 2
    @DannyHansen Right: in some update during the last eight years, the LaTeX kernel changed \@currenvir to not be \long as it used to be. Fixed by adding a *. – egreg Mar 25 '19 at 21:41

If you use pdftex, etex or xetex (I mean engine), you can define a fully expandable test:

\makeatletter \def\IfEnvir #1%
% implicit #2 "what if true"
% implicit #3 "what if false"
  \ifnum \strcmp{\@currenvir}{#1}=0


Such a conditional is defined in the gmutils package: \@ifenvir, but there it's \protected for some reason.

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  • If you prefer the \if… … \else … \fi form, just replace \expandafter\@first/secondoftwo with your stuff, but i'd suggest the arguments-form because it's robust to unbalanced \if's. – Natror May 20 '11 at 9:06
  • Please indent your code with four spaces (or use the '101010' button to do this) so that it is properly highlighted. Please don't use HTML for code formatting. Thanks. – Martin Scharrer May 20 '11 at 9:39
  • the command is \strcmp in XeTeX and \pdfstrcmp in pdfTeX. One can load pdftexcmds and use \pdf@strcmp in all engines (including LuaTeX). – egreg May 20 '11 at 10:04

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