learning c

#include <stdio.h>
#include <sys/resource.h>

typedef struct {
    unsigned long size, resident, share, text, lib, data, dt;
}St;

void readMemoryStatus()
{

    St r;

    FILE* file = fopen("/proc/self/statm", "r");

    if(file){

        int rv = fscanf(file,"%lu %lu %lu %lu %lu %lu %lu", &r.size, &r.resident, &r.share, &r.text, &r.lib, &r.data, &r.dt);

        if(rv == 7){
            printf("%lu %lu %lu %lu %lu %lu %lu\n", r.size, r.resident, r.share, r.text, r.lib, r.data, r.dt);
        }

        fclose(file);
    }

}


long int g_Variable = 0;

long int testas(long int i) {

    if(i <= 0) return 0;

    g_Variable++;

    readMemoryStatus();

    return testas(i - 1);

}

//long int -2147483648 2147483647

int  main() {
   long int i = 5;
   printf("\n%ld %ld\n", testas(i), g_Variable);
   printf("%ld\n", g_Variable);
   return 0;
}

/*
with -O0 and i = 500000;

in pages
...
3140 2403 353 1 0 2090 0
...
3141 2403 353 1 0 2091 0
...
3142 2403 353 1 0 2092 0
SEGFAULT (core dumped)

valgrind --tool=massif ./testas
Stack overflow in thread #1: can't grow stack to 0x1ffe801000
Process terminating with default action of signal 11 (SIGSEGV)

ulimit
stack size (kbytes, -s) 8192


ok with -03 and i = 500000:
1127 193 177 1 0 77 0

*/