23.3.1 Non-interactive behavior

Autoconf's generated `configure' scripts are designed to be non-interactive -- they should not prompt the user for input. Many users like the fact that `configure' can be used as part of a automated build process. By introducing code into `configure' which prompts a user for more information, you will prohibit unattended operation. Instead, you should use the AC_ARG_ENABLE macro in `configure.in' to add extra options to `configure' or consider runtime configuration (see section 23.3.2 Testing system features at application runtime).