Pileus Git - ~andy/sfvlug/blob - c/src/struct.c

   1 #include <stdio.h>
   2 #include <stdint.h>
   3
   4 int main()
   5 {
   6         /*
   7          * Structs
   8          */
   9         struct person {
  10                 char *name;
  11                 int   age;
  12         };
  13
  14         struct person andy = { "Andy", 33 };
  15
  16         printf("%s is %d years old!\n",
  17                         andy.name, andy.age);
  18         printf("\n");
  19
  20         /*
  21          * Typedefs
  22          */
  23         typedef struct {
  24                 char *name;
  25                 int   age;
  26         } person_t;
  27
  28         person_t andys = { "Andy Spencer", 33 };
  29
  30         printf("%s is %d years old!\n",
  31                         andys.name, andys.age);
  32         printf("\n");
  33
  34         /*
  35          * Pointers.
  36          */
  37         person_t *who = &andys;
  38
  39         printf("%s is %d years old!\n",
  40                         (*who).name, (*who).age);
  41
  42         printf("%s is %d years old!\n",
  43                         who->name, who->age);
  44         printf("\n");
  45
  46         /*
  47          * Unions.
  48          */
  49         union cake {
  50                 char *have;
  51                 char *eat;
  52         };
  53
  54         union cake chocolate = {};
  55
  56         chocolate.have = "Yes please";
  57         printf("Chocolate? %s!\n", chocolate.have);
  58         chocolate.eat = "Yum";
  59         printf("Chocolate? %s!\n", chocolate.eat);
  60         printf("Chocolate? %s!\n", chocolate.have);
  61         printf("\n");
  62
  63         /*
  64          * Unions.
  65          */
  66         union types {
  67                 uint32_t number;
  68                 char     string[4];
  69         };
  70
  71         union types abc = {
  72                 .string = "abc"
  73         };
  74
  75         printf("Number: %08x\n", abc.number);
  76         printf("String: %s\n",   abc.string);
  77
  78         return 0;
  79 }