How do I include a path to libraries in g++

Question

I am trying to include the path to extra libraries in my makefile, but I can't figure out how to get the compiler to use that path. so far I have:

g++ -g -Wall testing.cpp fileparameters.cpp main.cpp -o test

and I want to include the path to

/data[...]/lib

because testing.cpp includes files from that library. Also, I'm on a linux machine.

EDIT: Not a path to a library. Just to files that were included. My bad.

Answer 1

To specify a directory to search for (binary) libraries, you just use -L:

-L/data[...]/lib

To specify the actual library name, you use -l:

-lfoo  # (links libfoo.a or libfoo.so)

To specify a directory to search for include files (different from libraries!) you use -I:

-I/data[...]/lib

So I think what you want is something like

g++ -g -Wall -I/data[...]/lib testing.cpp fileparameters.cpp main.cpp -o test

These compiler flags (amongst others) can also be found at the GNU GCC Command Options manual:

• 3.16 Options for Directory Search

Answer 2

In your MakeFile or CMakeLists.txt you can set CMAKE_CXX_FLAGS as below:

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/path/to/your/folder")