sendmail, 4th Edition

Build with m4

The make(1) program^[33] is used to compile and install sendmail. The Build script creates not only an object working directory, but also an appropriate Makefile in that directory using m4(1). Unless you tell Build to do otherwise, the Makefile it creates will be based solely on information it finds in the appropriate devtools/OS and devtools/Site subdirectories.

For most sites, this default behavior will produce the desired result. For other sites, different defaults are needed.

In this section, we discuss those m4 directives necessary for building a Makefile. To understand m4(1), leap ahead to Chapter 17 on page 584, review the information there, then return here.

Creating a Makefile with Build is simplicity itself. First decide whether you wish to maintain your m4 file inside the sendmail source tree, or outside it. If you choose to maintain your m4 file inside the source tree, just name it devtools/Site/site.config.m4 (see Build sendmail on page 53 for details) and run Build like this:

% ./Build

Note that here we have chosen to maintain all our Build m4 files inside the sendmail source tree. This approach allows administrators to rebuild sendmail without needing to remember where the m4 file is located.

If you choose to maintain your m4 file outside the source tree, use the -f command-line switch with Build to specify the location of that file:

% ./Build -f /usr/local/configs/sendmail/oursite.m4

Note that here we have chosen to maintain all our Build m4 files in a directory ...