autoconf.info: Manual Configuration

Go forward to Site Configuration
Go backward to Portable Shell
Go up to Top
Go to the top op autoconf

Manual Configuration

A few kinds of features can't be guessed automatically by running test
programs.  For example, the details of the object-file format, or
special options that need to be passed to the compiler or linker.  You
can check for such features using ad-hoc means, such as having
`configure' check the output of the `uname' program, or looking for
libraries that are unique to particular systems.  However, Autoconf
provides a uniform method for handling unguessable features.