\batchmode \long\def\typeout#1{\immediate\write-1{#1}} \def\ { }% \output{\deadcycles0\setbox0\box255} \def\E#1{} \typeout{*** \string\par\ in non-\string\long\ cmd.} \E{a b} \E{c\par d} \outer\def\F{hoge} \typeout{*** \string\outer\ cmd in \string\message\ and \string\write.} \immediate\write-1{\F} \message{\F} \typeout{*** \string\outer\ cmd in conditionals.} \iftrue a\F \else b\F \fi \typeout{*** \string\outer\ cmd in alignment preambles.} \halign{#\F&#\cr a&d\cr} \typeout{*** \string\par\ in math mode.} $ x+1 = a\par b$ $$\eqno{a}\par$$ $$ aaa\par$$ \typeout{*** \string\pdfprimitive\ and non-primitive.} \ifdefined\primitive \primitive\batchmode \primitive\hoge \else \pdfprimitive\batchmode \pdfprimitive\hoge \fi \typeout{===============} \suppresslongerror=1 \suppressoutererror=1 \suppressmathparerror=1 \typeout{*** \string\par\ in non-\string\long\ cmd.} \E{a b} \E{c\par d} \typeout{*** \string\outer\ cmd in \string\message\ and \string\write.} \immediate\write-1{\F} \message{\F} \typeout{*** \string\outer\ cmd in conditionals.} \iftrue a\F \else b\F \fi \typeout{*** \string\outer\ cmd in alignment preambles.} \halign{#\F&#\cr a&d\cr} \typeout{*** \string\par\ in math mode.} $ x+1 = a\par b$ $$\eqno{a}\par$$ $$ aaa\par$$ \bye