Is there a \die command?

Question

Is there a command that generates the error or warning of my choice? I'm planning to put it in an \ifthenelse, so it can't be a syntax error.

Answer 1

There are commands \GenericInfo, \GenericWarning and \GenericError. For class and package writers there are also \Class… and \Package… equivalents, described in the clsguide.

An example:

\documentclass{minimal}

\GenericWarning{}{A simple warning}

\GenericError{(cont.)\space\space}
  {This is a\MessageBreak
    multi-line error\MessageBreak
    message}
  {Describe here where to go for more information}
  {This is the error help (type H to see me)}

\begin{document}
\end{document}