Wrapper for distinguishing autoconf 2.13 and 2.50
autoconf [ options ]
autoheader [ options ]
autoreconf [ options ]
Autoconf is an automatic configure script builder with two major version series: 2.13 and earlier, 2.50 and later. Versions within either series are largely compatible, but the two series are largely incompatible. When both versions are installed, as they are on your system (given that you're reading this manpage), Debian selects between the two versions simultaneously. This manpage documents how the automatic selection works. If you are actually looking for the documentation for either version of Autoconf, then refer to the SEE ALSO section below.
Automatic version selection works via a wrapper script installed under the names autoconf, autoheader, and autoreconf. Each of these attempts to detect which Autoconf is needed and run the correct version of the tool.
There are no wrappers for autoupdate, autoscan, or ifnames. These are not used during a package build. Choose the proper version by hand.
The following heuristics are used to choose an Autoconf version:
* If file
configure.ac exists, Autoconf 2.50 is used. Autoconf 2.13 used the name configure.in instead, but version 2.50 supports both.
(Usually autoconf is run without nonoption arguments. If a filename is supplied on the command line, then version 2.50 is used if the filename ends in .ac.)
configure.in (or the file specified on the command line, if any) is read. It is checked for the presence of an AC_PREREQ directive. If it specifies a minimum version higher than 2.13, Autoconf 2.50 is used. aclocal.m4, if present, is also scanned.
* Otherwise, Autoconf 2.13 is used.
To force Autoconf 2.13 to be used, name the Autoconf input file configure.in and omit the use of AC_PREREQ() or specify a minimum version of 2.13 or earlier. To force Autoconf 2.50 to be used, name the input file configure.ac or use AC_PREREQ(2.50).
I recommend not calling the programs autoconf2.13 or autoconf2.50, etc., directly, instead of through the wrappers. When used with programs like Automake, these direct calls won't propagate through into the Makefile, so later re-autoconf'ings won't use the correct version. It's better to use one of the methods explained above to force a particular version.
David MacKenzie, with help from Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor, Roland McGrath, Noah Friedman, David D. Zuhn, and many others. This manpage written by Ben Pfaff <[email protected]> for the Debian GNU/Linux autoconf2.13 package.