examples/c/hello.c
#include <stdio.h>

char * echo(char * what)
{
   return what;
}

int add_int(int a, int b)
{
    int sum = a+b;
    return sum;
}

int add_int(int a, int b)
{
    int sum = a+b;
    return sum;
}


int main(void)
{
    printf("hello\n");
    printf("%d\n", add_int(2, 3));
    printf("%s\n", echo("Foo"));
    return 0;
}

gcc -o hello hello.c

gcc -o hello.so -shared -fPIC hello.c

examples/c/hello.py
from ctypes import cdll
from ctypes import c_char_p

hello_lib = cdll.LoadLibrary("hello.so")

print(hello_lib.add_int(4, 5))         # 9

print(hello_lib.echo('Hello World'))   # 153977204


hello_lib.echo.restype = c_char_p
print(hello_lib.echo('Hello World'))   # Hello World