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 Macro Names, for a description of the new scheme. Although the old names still work (see 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
autoupdate accepts the following options: