Introduction

In this chapter we describe how to interface TeXmacs with an extern application. Such interfaces should be distributed in the form of plugins. The plug-in may either contain the extern application, or provide the “glue” between TeXmacs and the application. Usually, interfaces are used interactively in shell sessions (see Text→Session). But they may also be designed for background tasks, such as spell checking or typesetting.

The communication between TeXmacs and the application takes place using a customizable input format and the special TeXmacs meta-format for output from the plug-in. The meta-format enables you to send structured output to TeXmacs, using any common format like verbatim, LaTeX, Postscript, HTML, or TeXmacs itself. This is useful when adding a TeXmacs interface to an existing system, since LaTeX or Postscript output routines are often already implemented. It will then suffice to put the appropriate markers in order to make a first interface with TeXmacs.

As soon as basic communication between your application and TeXmacs is working, you may improve the interface in many ways. Inside shell sessions, there is support for prompts, default inputs, tab-completion, mathematical and multi-line input, etc. In general, your application may take control of TeXmacs and modify the user interface (menus, keyboard, etc.) or add new Scheme routines to TeXmacs. Your application may even extend the typesetter.

In the directory $TEXMACS_PATH/examples/plugins, you can find many examples of simple plug-ins. In the next sections, we will give a more detailed explanation of the interfacing features of TeXmacs on the hand of these examples. In order to try one of these examples, we recall that you just have to copy it to either one of the directories

    $TEXMACS_PATH/plugins
    $TEXMACS_HOME_PATH/plugins

and run the Makefile (if there is one).