struct.c

#include <stdio.h>

int global = 42;

struct s_t
{
    long int a;
    int* b;
};

void foo(struct s_t s) {
    printf("\ngreetings from foo!\n");
}

int main() {
    struct s_t s = { .a = 7L, .b = &global };

    foo(s);
}