6.3.1 aclocal Options
aclocal accepts the following options:
- Look for the automake-provided macro files in dir instead of
in the installation directory. This is typically used for debugging.
- Look for the system-wide third-party macro files (and the special
dirlist file) in dir instead of in the installation
directory. This is typically used for debugging.
- Run command on M4 file that would be installed or overwritten
by --install. The default command is ‘diff -u’.
This option implies --install and --dry-run.
- Do not actually overwrite (or create) aclocal.m4 and M4
files installed by --install.
- Print a summary of the command line options and exit.
- Add the directory dir to the list of directories searched for
- Install system-wide third-party macros into the first directory
specified with ‘-I dir’ instead of copying them in the
Note that this will happen also if dir is an absolute path.
When this option is used, and only when this option is used,
aclocal will also honor ‘#serial number’ lines
that appear in macros: an M4 file is ignored if there exists another
M4 file with the same basename and a greater serial number in the
search path (see Serials).
- Always overwrite the output file. The default is to overwrite the output
file only when really needed, i.e., when its contents changes or if one
of its dependencies is younger.
This option forces the update of aclocal.m4 (or the file
specified with --output below) and only this file, it has
absolutely no influence on files that may need to be installed by
- Cause the output to be put into file instead of aclocal.m4.
- Prints the name of the directory that aclocal will search to
find third-party .m4 files. When this option is given, normal
processing is suppressed. This option was used in the past by
third-party packages to determine where to install .m4 macro
files, but this usage is today discouraged, since it causes
‘$(prefix)’ not to be thoroughly honoured (which violates the
GNU Coding Standards), and a similar semantics can be better obtained
with the ACLOCAL_PATH environment variable; see Extending aclocal.
- Print the names of the files it examines.
- Print the version number of Automake and exit.
- Output warnings falling in category. category can be
- dubious syntactic constructs, underquoted macros, unused macros, etc.
- unknown macros
- all the warnings, this is the default
- turn off all the warnings
- treat warnings as errors
All warnings are output by default.
The environment variable WARNINGS is honored in the same
way as it is for automake (see automake Invocation).