When installing several packages using the same setup, it can be
convenient to create a file to capture common settings.
If a file named prefix/share/config.site exists,
configure will source it at the beginning of its execution.
Recall the command from the previous section:
~/amhello-1.0 % ./configure --prefix ~/usr CC=gcc-3 \ CPPFLAGS=-I$HOME/usr/include LDFLAGS=-L$HOME/usr/lib
Assuming we are installing many package in ~/usr, and will
always want to use these definitions of
LDFLAGS, we can automate this by creating the following
test -z "$CC" && CC=gcc-3 test -z "$CPPFLAGS" && CPPFLAGS=-I$HOME/usr/include test -z "$LDFLAGS" && LDFLAGS=-L$HOME/usr/lib
Now, any time a configure script is using the ~/usr prefix, it will execute the above config.site and define these three variables.
~/amhello-1.0 % ./configure --prefix ~/usr configure: loading site script /home/adl/usr/share/config.site …
See Setting Site Defaults in The Autoconf Manual, for more information about this feature.