#include "stdio.h" /* this is needed only to define the NULL */ #define RECORDS 6 main() { struct animal { char name[25]; /* The animals name */ char breed[25]; /* The type of animal */ int age; /* The animals age */ struct animal *next; /* a pointer to another record of this type */ } *point, *start, *prior; /* this defines 3 pointers, no variables */ int index; /* the first record is always a special case */ start = (struct animal *)malloc(sizeof(struct animal)); strcpy(start->name,"General"); strcpy(start->breed,"Mixed Breed"); start->age = 4; start->next = NULL; prior = start; /* a loop can be used to fill in the rest once it is started */ for (index = 0;index < RECORDS;index++) { point = (struct animal *)malloc(sizeof(struct animal)); strcpy(point->name,"Frank"); strcpy(point->breed,"Laborador Retriever"); point->age = 3; prior->next = point; /* point last "next" to this record */ point->next = NULL; /* point this "next" to NULL */ prior = point; /* this is now the prior record */ } /* now print out the data described above */ point = start; do { prior = point->next; printf("%s is a %s, and is %d years old.\n", point->name, point->breed, point->age); point = point->next; } while (prior != NULL); /* good programming practice dictates that we free up the */ /* dynamically allocated space before we quit. */ point = start; /* first block of group */ do { prior = point->next; /* next block of data */ free(point); /* free present block */ point = prior; /* point to next */ } while (prior != NULL); /* quit when next is NULL */ }