Generate random string for member of struct

I would like to know how I can generate a random string for a member of a struct and assign this value to the member of the struct.

My struct is defined this way:

struct student{
       int key;
       char name[25];
}

I already generated random numbers of the member "key" of struct.

Part of the code of the method:

    struct student s;
    int r = rand() % 5000;
    s.key=r;

Note: With srand(time(NULL)); defined in main().

How I do it for s.name?