Thread: error: request for member 'struct variable' in something not a str

I want to assign msg.modification_time, but with following codebit I only get "error: request for member 'modification_time' in something not a structure or union". I can't figure out why! Can someone please guide me towards the solution?

Code:

struct meta {
  char modification_time[10];
};
void something() {
  struct meta *msg = malloc(sizeof(struct meta));
  struct timeval tv;
  time_t tidNaa;
  gettimeofday(&tv, NULL);
  tidNaa = tv.tv_sec;
  strftime(msg.modification_time,10,"%T",localtime(&tidNaa));
}

Btw: I also tried to declare a char timenow[10] in main, and use strftime(timenow,10,"%T",localtime(&tidNaa));
and that worked. So it is propably the struct that is causing the troubles. What's wrong?

msg is a pointer; thus you must write
msg->modification_time
But, that is not necessary either.
You can change
struct meta *msg = malloc(sizeof(struct meta));
to
struct meta msg;
And all will work fine. Otherwise you have to free, which you don't.

Also, Stroustrup: C++ Style and Technique FAQ

msg->something is a shorthand for (*msg).something.
Because "." has lower precedence than "*", *msg.something would essentially become *(msg.something). But msg is a pointer, and thus does not have any members. But what it points to have members; thus you need to dereference it first.