15.3 Using autoupdate to Modernize `configure.ac'

The autoupdate program updates a `configure.ac' file that calls Autoconf macros by their old names to use the current macro names. In version 2 of Autoconf, most of the macros were renamed to use a more uniform and descriptive naming scheme. See section 9.2 Macro Names, for a description of the new scheme. Although the old names still work (see section 15.4 Obsolete Macros, for a list of the old macros and the corresponding new names), you can make your `configure.ac' files more readable and make it easier to use the current Autoconf documentation if you update them to use the new macro names.

If given no arguments, autoupdate updates `configure.ac', backing up the original version with the suffix `~' (or the value of the environment variable SIMPLE_BACKUP_SUFFIX, if that is set). If you give autoupdate an argument, it reads that file instead of `configure.ac' and writes the updated file to the standard output.

autoupdate accepts the following options:

`--help'

`-h'

Print a summary of the command line options and exit.

`--version'

`-V'

Print the version number of Autoconf and exit.

`--verbose'

`-v'

Report processing steps.

`--debug'

`-d'

Don't remove the temporary files.

`--force'

`-f'

Force the update even if the file has not changed. Disregard the cache.

`--include=dir'

`-I dir'

Also look for input files in dir. Multiple invocations accumulate. Directories are browsed from last to first.