gcc -c -Wall -Werror -fPIC shared.cc  -shared -o libshared.so
gcc -L. -Wall share.cc -o share -lshared

share.cc:
#include<stdio.h>
extern unsigned int add(unsigned int a, unsigned int b);

int main(void)
{
    unsigned int a = 1;
    unsigned int b = 2;
    unsigned int result = 0;

    result = add(a,b);

    printf("\n The result is [%u]\n",result);
    return 0;
}

shared.cc:
#include<stdio.h>
extern unsigned int add(unsigned int a, unsigned int b);

unsigned int add(unsigned int a, unsigned int b)
{
    printf("\n Inside add()\n");
    return (a+b);
}