Hi Nick, Mauro, On Thu, 2019-08-15 at 09:56 -0400, Nick Bowler wrote: > Hi Chris, > > On 8/15/19, Chris Packham <Chris.Packham@xxxxxxxxxxxxxxxxxxx> wrote: > > > > I'm trying to get a value provided on the ./configure invocation > > through to C code so it can be used. I'm trying to do this with > > AC_DEFINE but maybe this is a job for something else. > [...] > > > > AC_DEFINE([ENTITY],[${enable_entity}],[Entity]) > [...] > > > > In file included from <command-line>:0:0: > > test.c: In function ‘main’: > > ./config.h:5:16: error: ‘$’ undeclared (first use in this function) > > #define ENTITY ${enable_entity} > > > > Which is a bit too literal. I suspect I'm missing something (like > > AC_SUBST). But I can't for all the searching figure out how to get > > a > > value from the ./configure invocation through to the end program. > You must use AC_DEFINE_UNQUOTED[1] if you want shell expansion to > be performed on the value. > > [1] https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoco > nf-2.69/autoconf.html#Defining-Symbols > > Hope that helps, > Nick Yes thanks AC_DEFINE_UNQUOTED did the trick. For mailing list archive readers I had a typo in my AC_ARG_ENABLE as well. This is the delta to my original post that now works as expected diff --git a/configure.ac b/configure.ac index 259027e..ed6830a 100644 --- a/configure.ac +++ b/configure.ac @@ -9,7 +9,7 @@ AC_CONFIG_FILES([Makefile]) AC_ARG_ENABLE([entity], [AS_HELP_STRING([--enable-entity], [Set entity @<:@default=World@:>@])], [], - [enable_enity=World]) + [enable_entity=World]) -AC_DEFINE([ENTITY],[${enable_entity}],[Entity]) +AC_DEFINE_UNQUOTED([ENTITY],["${enable_entity}"],[Entity]) AC_OUTPUT _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf