Library examples

This repo contains examples of compiling, linking, and loading C libraries in both C and Python.

Building in C

The provided makefile defines three targets for building, as a way to demonstrate each method of linking.

• make main-static
  • Compile main.c and mylib.c and link statically
• make main-shared
  • Compile main.c and mylib.c and link as shared library
• make main-dynamic
  • Compile dyn_main.c and mylib.c, and do not link

Running in C

For the main-static and main-dynamic build targets, you can simply run the resulting executable with:

./a.out

However, the main-shared target requires you to add the libs folder to the LD_LIBRARY_PATH, a la:

LD_LIBRARY_PATH=libs:$LD_LIBRARY_PATH ./a.out

The LD_LIBRARY_PATH variable tells the shared object loader where to find library files on startup. By default, programs will look in your system library folders (IE: /usr/lib on Linux) first, and then wherever you tell them to after.

Running in Python

Compile the shared library file first, and then launch main.py with Python:

make library
python3 main.py