[Chapter 19] 19.5 Pitfalls
Author: Bryan Costales & Eric Allman
Date: 1999-01-06T19:18:34Z

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| Chapter 19 V8 m4 Configuration |

## 19.5 Pitfalls

The use of the `#` to place comments into an `mc` file for eventual transfer to your configuration file may not work as expected. The `#` is not special to m4, so m4 continues to process a line even though that line is a comment. So instead of

>     # Here we define $m as our domain

(which would see `define` as an m4 keyword), use single quotes to insulate all such comments from m4 interpretation:

>     # `Here we define $m as our domain'

19.4 m4 Macros by Function |  | 19.6 Alphabetized m4 Macros