14.3 The dist Hook

Occasionally it is useful to be able to change the distribution before it is packaged up. If the dist-hook rule exists, it is run after the distribution directory is filled, but before the actual tar (or shar) file is created. One way to use this is for distributing files in subdirectories for which a new ‘Makefile.am’ is overkill:

dist-hook:
        mkdir $(distdir)/random
        cp -p $(srcdir)/random/a1 $(srcdir)/random/a2 $(distdir)/random

Another way to use this is for removing unnecessary files that get recursively included by specifying a directory in EXTRA_DIST:

EXTRA_DIST = doc

dist-hook:
        rm -rf `find $(distdir)/doc -name CVS`

Two variables that come handy when writing dist-hook rules are ‘$(distdir)’ and ‘$(top_distdir)’.

‘$(distdir)’ points to the directory where the dist rule will copy files from the current directory before creating the tarball. If you are at the top-level directory, then ‘distdir = $(PACKAGE)-$(VERSION)’. When used from subdirectory named ‘foo/’, then ‘distdir = ../$(PACKAGE)-$(VERSION)/foo’. ‘$(distdir)’ can be a relative or absolute path, do not assume any form.

‘$(top_distdir)’ always points to the root directory of the distributed tree. At the top-level it's equal to ‘$(distdir)’. In the ‘foo/’ subdirectory ‘top_distdir = ../$(PACKAGE)-$(VERSION)’. ‘$(top_distdir)’ too can be a relative or absolute path.

Note that when packages are nested using AC_CONFIG_SUBDIRS (see section Nesting Packages), then ‘$(distdir)’ and ‘$(top_distdir)’ are relative to the package where ‘make dist’ was run, not to any sub-packages involved.