Ensure that a recent enough version of Autoconf is being used. If the version of Autoconf being used to create configure is earlier than version, print an error message to the standard error output and exit with failure (exit status is 63). For example:

          AC_PREREQ([2.60])
     

This macro is the only macro that may be used before AC_INIT, but for consistency, you are invited not to do so.

State that, in addition to the Free Software Foundation's copyright on the Autoconf macros, parts of your configure are covered by the copyright-notice.

The copyright-notice shows up in both the head of configure and in ‘configure --version’.

Copy revision stamp revision-info into the configure script, with any dollar signs or double-quotes removed. This macro lets you put a revision stamp from configure.ac into configure without RCS or CVS changing it when you check in configure. That way, you can determine easily which revision of configure.ac a particular configure corresponds to.

For example, this line in configure.ac:

          AC_REVISION([$Revision: 1.1 $])
     

produces this in configure:

          #!/bin/sh
          # From configure.ac Revision: 1.30