Can we put two files with main() in makefile? - c++

Question

I have client server code client.cpp and server.cpp both with main().
Server need to be executed first and remain alive till not uninterrupted.
server.cpp includes two cpp files that I have created:
#include "serverFunction.cpp"
#include "serverFunction2.cpp"
Both of this also include serverFunction.h .
How to write makefile for this? I have used pthread so -lpthread at the end.
Individually I compile in this manner:
g++ -o a LinServer.cpp -lpthread
I tried with this:
all: LinServer LinClient
LinServer:
g++ -o a LinServer.cpp -pthread
LinClient:
g++ -o b LinClient.cpp -pthread
But it gives this error:
LinServer.o: In function `main':
LinServer.cpp:(.text+0x6dd): undefined reference to `pthread_create'
LinServer.cpp:(.text+0x6e9): undefined reference to `pthread_detach'
LinServer.o: In function `__static_initialization_and_destruction_0(int, int)':
LinServer.cpp:(.text+0xb3e): undefined reference to `std::ios_base::Init::Init()'
LinServer.cpp:(.text+0xb55): undefined reference to `std::ios_base::Init::~Init()'
LinServer.o:(.eh_frame+0x7b): undefined reference to `__gxx_personality_v0'
collect2: error: ld returned 1 exit status
make: *** [LinServer] Error 1

Answer 1

You have specified the library incorrectly:
g++ -o a LinServer.cpp -pthread
It should be -lpthread, not -pthread (the -l option means compiling with library).
Your problems are not related with having two main() functions, but the answer is - yes, you can compile two files with main() function in the same Makefile, but only if the files belongs to different output files (different binaries).
Your error messages look like there is something wrong with your linker settings or with your configuration of standard C++ library (the linker seems unable to see it).