Re: Using and detecting environment variables as flags

[John Ling]

Hi Bruce.

So I have the following in my configure.ac:

AC_SEARCH_LIBS([compress], [z], ,)

So if this Z library exists then I want the build process to include 
this library during linking.  Otherwise I run into errors about not 
being able to find the 'compress' function in the Z library.

I have a Makefile.am that does some of the build process, but it also 
calls a Makefile.loader with a target that states 'make -f 
Makefile.loader', which is a Makefile that also must link with the Z 
library if it exists.  I want to detect the availability of this Z 
library during configure time, and then pass this information all the 
way to Makefile.loader where I can decide whether I can add a '-lz' in 
my LIBS variable, in this Makefile.loader, in order for it to link to 
this Z library.

What is this substitution string in this case for the Z library and how 
can I use it?

Thanks,
John

Bruce Korb wrote:

> What is the real problem you are trying to solve?  Normally, autoconf
> results get stored into substitution strings that wind up as
> Makefile macros and set appropriately in the derived Makefile.
>