This function return 0 when the sub string was not found at the given string or unsigned integer number bigger then 0, which indicate the number of occupancy.
int my_strstr(const char* str, const char* to_find){
static int num_of_occur = 0;
while (*str) {
const char* tmp_s = str;
const char* tmp_f = to_find;
while ( (*tmp_f == *tmp_s) && *tmp_f)
{
tmp_f++;
tmp_s++;
}
if(!(*tmp_f))
num_of_occur++;
str++;
}
return num_of_occur;
}