TeX/endinput

Synopsis \endinput Description This command terminates the input process in the middle of a file. It is redundant at the end of a file. On encountering this command, TeX continues reading until the end of the line. This makes it possible to wrap \endinput in an \if oneliner. Example \def\false{false} \def\students{false} % Questions, for teachers and students ... \ifx\students\true\endinput\fi % Answers, for teacher only If the \if statement cannot be a oneliner (for legibility reasons, say), then one can use \expandafter: \ifx\students\true % ... various other statements ... \expandafter\endinput \fi