Question

I’m having issues writing a function that allocates a struct in C. Ideally, I want to have the function fill the fields of the struct with parameters passed into it.

I have defined the struct in my header file like so:

typedef struct {
  char name[NAME_SIZE]; //Employee name
  int birthyear; //Employee birthyear
  int startyear; //Employee start year
} Employee;

And this is what I have for my function currently:

void make_employee(char _name, int birth_year, int start_year) {
  Employee _name  = {_name,birth_year,start_year}; //allocates struct with name
} /* end make_employee function */

Any advice on how to accomplish this?

Answer 1

You have to return a pointer allocated via malloc:

Employee* new_employee(char *_name, int birth_year, int start_year) {
    struct Employee* ret = (struct Employee*)malloc(sizeof(struct Employee));
    ret->name = _name;
    ret->birth_year = birth_year;
    ret->start_year = start_year;
    return ret;
}

two more things: (1) you should make the struct definition of name a char* instead of char[NAME_SIZE]. Allocating a char array makes the struct much bigger and less flexible. All you really need is a char* anyway. And (2) change the function definition to char*.