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By default, aclocal
searches for .m4 files in the
following directories, in this order:
acdir
This directory is intended for third party .m4 files, and is
configured when automake
itself is built. This is
@datadir@/aclocal/, which typically
expands to ${prefix}/share/aclocal/. To find the compiled-in
value of acdir, use the --print-ac-dir option
(see aclocal Options).
acdir-APIVERSION
This is where the .m4 macros distributed with Automake itself
are stored. APIVERSION depends on the Automake release used;
for example, for Automake 1.11.x, APIVERSION = 1.11
.
As an example, suppose that automake-1.11.2
was configured with
--prefix=/usr/local. Then, the search path would be:
The paths for the acdir and acdir-APIVERSION directories can be changed respectively through aclocal options --system-acdir and --automake-acdir (see aclocal Options). Note however that these options are only intended for use by the internal Automake test suite, or for debugging under highly unusual situations; they are not ordinarily needed by end-users.
As explained in (see aclocal Options), there are several options that can be used to change or extend this search path.
Any extra directories specified using -I options (see aclocal Options) are prepended to this search list. Thus, ‘aclocal -I /foo -I /bar’ results in the following search path:
There is a third mechanism for customizing the search path. If a
dirlist file exists in acdir, then that file is assumed to
contain a list of directory patterns, one per line. aclocal
expands these patterns to directory names, and adds them to the search
list after all other directories. dirlist entries may
use shell wildcards such as ‘*’, ‘?’, or [...]
.
For example, suppose acdir/dirlist contains the following:
/test1 /test2 /test3*
and that aclocal
was called with the ‘-I /foo -I /bar’ options.
Then, the search path would be
/foo
/bar
/test1
/test2
and all directories with path names starting with /test3
.
If the --system-acdir=dir option is used, then
aclocal
will search for the dirlist file in
dir; but remember the warnings above against the use of
--system-acdir.
dirlist is useful in the following situation: suppose that
automake
version 1.11.2
is installed with
‘--prefix=/usr’ by the system vendor. Thus, the default search
directories are
/usr/share/aclocal/
/usr/share/aclocal-1.11/
However, suppose further that many packages have been manually installed
on the system, with ${prefix}=/usr/local
, as is typical. In
that case, many of these “extra” .m4 files are in
/usr/local/share/aclocal. A way to force /usr/bin/aclocal
to find these “extra” .m4 files is to export ACLOCAL_PATH
to ‘/usr/local/share/aclocal’. This is a little inconvenient,
since it requires either explicit user cooperation, or editing of the
system global shell initialization file. With dirlist, one may
create a file /usr/share/aclocal/dirlist containing only the
single line
/usr/local/share/aclocal
Now, the “default” search path on the affected system is
/usr/share/aclocal/
/usr/local/share/aclocal/
/usr/share/aclocal-1.11/
without the need of any explicit ACLOCAL_PATH
setting.
Similarly, dirlist can be handy if you have installed a local
copy of Automake in your account and want aclocal
to look
for macros installed at other places on the system.
The fourth and last mechanism to customize the macro search path is
also the simplest. Any directory included in the colon-separated
environment variable ACLOCAL_PATH
is added to the search path
and takes precedence over system directories (including those found via
dirlist), with the exception of the versioned directory
acdir-APIVERSION (see Macro Search Path). However, directories
passed via -I will take precedence over directories in
ACLOCAL_PATH
.
Also note that, if the --install option is used, any .m4
file containing a required macro that is found in a directory listed in
ACLOCAL_PATH
will be installed locally.
In this case, serial numbers in .m4 are honored too,
see Serials.
Conversely to dirlist, ACLOCAL_PATH
is useful if you are
using a global copy of Automake and want aclocal
to look for
macros somewhere under your home directory.
Next: Extending aclocal, Previous: aclocal Options, Up: aclocal Invocation [Contents][Index]