Calling Rust from C (project)

In this section, we will demonstrate the setup needed to build a Rust shared library (with a .so extension on Linux) incorporating an FFI interface and invoke it from a C program. The C program would be a simple program that just prints out a greeting message. The example is deliberately kept simple to enable you (as you're not expected to be familiar with complex C syntax) to focus on the steps involved, and for easy verification of this first FFI program in a variety of operating system environments.

Here are the steps that we will go through to develop and test a working example of a C program that calls a function from a Rust library using the FFI interface:

1. Create a new Cargo lib project.
2. Modify Cargo.toml to specify that we want a shared library to be built.
3. Write an FFI in Rust (in the form of a C-compatible API).
4. Build the Rust shared library.
5. Verify whether the Rust shared library has been built correctly.
6. Create...