multiple definition of main error in eclipse using C

Question

I'm trying to generate two exes, client and server using a C Project in eclipse. Both have main functions since they are different exes. Both use a common confutils.c file. How do I solve the multiple definitions of main problem. I know that we cannot have two mains in a single project. My makefile looks like below.

.c.o:
    gcc -g -c $?

# compile client and server
all: confclient confserver

# compile client only
confclient: confclient.o confutils.o
    gcc -g -o confclient confclient.o  confutils.o

# compile server program
confserver: confserver.o confutils.o
    gcc -g -o confserver confserver.o  confutils.o

I replaced eclipse file with this. I don't know if eclipse read it properly. I don't like to split this project into two since it is such a simple program. I am able to run these files in unix with no issues. I'm trying to find if there is an option in eclipse using which we can setup build configurations.

Answer 1

It's possible to define multiple build configurations - each having different set of files that are built.

First open Project properties and navigate to Manage Configurations:

Create a new build configuration:

And set it active:

Finally define filter excluding file(s) to ensure that you build a source file with main() you want to use only:

And that's it:

Now you can choose target build configuration from Menu > Project > Build Configurations > Set Active.

Answer 2

I think you can set up multiple "Build Configurations" to avoid this. Under "Project" in the menu bar you can choose your active build configuration.

There are ways to exclude files in different configurations. Under your project properties you go to "C/C++ General", "Paths and Symbols" and here you choose "Source Location". Top most you can now choose your build configuration and then define different sorurce locations for you different build configurations. Here you add folders for your source code, and, here comes the trick, for the folders you choose to include you can put filter to ignore specific files.

In your case I would make two Build Configurations, one for confclient and for this one I would exclude confserver.c from the scource location, and vice versa.

You will need to build you project twice, but the utilspart will be left unchanged and hence it wont recompile which is a benefit over having two projects. Also it might be nice to have all the code in the same project since I guess the code on the server side and client side will be connected.