Some software packages require complex site-specific information. Some examples are host names to use for certain services, company names, and email addresses to contact. Since some configuration scripts generated by Metaconfig ask for such information interactively, people sometimes wonder how to get that information in Autoconf-generated configuration scripts, which aren't interactive.
Such site configuration information should be put in a file that is
edited only by users, not by programs. The location of the file
can either be based on the prefix variable, or be a standard
location such as the user's home directory. It could even be specified
by an environment variable. The programs should examine that file at
runtime, rather than at compile time. Runtime configuration is more
convenient for users and makes the configuration process simpler than
getting the information while configuring. See Variables for Installation Directories, for more information on where to put data files.