\input regression-test.tex
\DocumentMetadata{tagging=on,lang=en-US}
\documentclass{article}
\usepackage{ansiterm}
\begin{document}

Plain paragraph before.

% Guarded on top of excludetests (see build.lua): even run by explicit
% name, this only actually executes a shell command once a human has
% deliberately opted in here, rather than the moment someone tries it.
%
% Two things had to be worked around to get this guard right:
%  - fancyvrb's raw file-scanning for \begin{ansitermexec}...\end{...}
%    cannot survive being nested inside a brace-delimited macro argument,
%    so the environment call below sits behind a plain \if, not an expl3
%    TF conditional -- comparing the flag itself can still use expl3, as
%    long as its own true/false branches stay free of that scanning.
\newif\ifansitermrunexec
\ExplSyntaxOn
\tl_set:Ne \l_tmpa_tl
  { \directlua{ tex.print(os.getenv("ANSITERM_RUN_EXEC_TESTS") or "") } }
\str_if_eq:VnTF \l_tmpa_tl { 1 }
  { \ansitermrunexectrue }
  { \ansitermrunexecfalse }
\ExplSyntaxOff
\ifansitermrunexec
\begin{ansitermexec}[show-input=true,cache=refresh,lines={1-}]
printf 'red\n'
printf 'green\n'
\end{ansitermexec}
\else
\TYPE{skipped~(set~ANSITERM_RUN_EXEC_TESTS=1~to~run)}
\fi

\clearpage
\SHOWPDFTAGS
\end{document}