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Learning GNU Emacs, Second Edition by Eric S. Raymond, Bill Rosenblatt, Debra Cameron

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Marking up Text for troff and nroff

Except for a few conveniences thrown in, nroff mode is just like text mode. For the purposes of this discussion, there is no difference between nroff and its relatives troff and groff; the commands discussed here work for the entire troff family.

To enter nroff mode, type ESC x nroff-mode RETURN. Nroff appears on the mode line. The nroff mode provides four substantial features:

  • It redefines the meaning of a paragraph by changing the regular expression for the paragraph-separate variable. With this setting, the fill-paragraph command (ESC q) works correctly.

  • It provides some special commands for navigating in a troff document. Using these commands, you can move forward and backward, jumping over all troff commands.

  • A special “electric nroff mode” (a minor mode associated with nroff mode) automatically supplies matching pairs of certain formatting commands.

  • It provides some features for inserting comments.

Paragraph Formatting

We’ll take these features one at a time. First, paragraph separation: if you do a lot of text editing and get used to typing ESC q (for fill-paragraph), troff documents will cause you misery. Emacs usually determines when a paragraph ends by looking for blank lines. troff documents usually don’t have any blank lines, so Emacs tries to reformat the entire file, creating a big mess. (Luckily, in Emacs 19, the undo command, C-x u, is powerful enough to clean up the mess.)

All troff formatting commands (usually called requests ...

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