16.5.4 @value Example

You can use the @value command to minimize the number of places you need to change when you record an update to a manual. See GNU Sample Texts, for the full text of an example of using this to work with Automake distributions.

This example is adapted from The GNU Make Manual.

1. Set the flags:

   @set EDITION 0.35 Beta
   @set VERSION 3.63 Beta
   @set UPDATED 14 August 1992
   @set UPDATE-MONTH August 1992
   

2. Write text for the @copying section (see @copying):

   @copying
   This is Edition @value{EDITION},
   last updated @value{UPDATED},
   of @cite{The GNU Make Manual},
   for @code{make}, version @value{VERSION}.
   
   Copyright …
   
   Permission is granted …
   @end copying
   

3. Write text for the title page, for people reading the printed manual:

   @titlepage
   @title GNU Make
   @subtitle A Program for Directing Recompilation
   @subtitle Edition @value{EDITION}, …
   @subtitle @value{UPDATE-MONTH}
   @page
   @insertcopying
   …
   @end titlepage
   

   (On a printed cover, a date listing the month and the year looks less fussy than a date listing the day as well as the month and year.)

4. Write text for the Top node, for people reading the Info file:

   @ifnottex
   @node Top
   @top Make
   
   This is Edition @value{EDITION},
   last updated @value{UPDATED},
   of @cite{The GNU Make Manual},
   for @code{make}, version @value{VERSION}.
   @end ifnottex
   

   After you format the manual, the @value constructs have been expanded, so the output contains text like this:

   This is Edition 0.35 Beta, last updated 14 August 1992,
   of `The GNU Make Manual', for `make', Version 3.63 Beta.
   

When you update the manual, you change only the values of the flags; you do not need to edit the three sections.