reallocプロジェクト - bg1wiki @ ウィキ

realloc.c

#include <stdio.h>
#include <stdlib.h>
 
int main(void){
 
  int *p_realloc;
  int i;
 
  p_realloc = NULL;
 
  printf("malloc example.\n");
 
  p_realloc = (int *)malloc(sizeof(int) * 5);
 
  if (p_realloc != NULL){
    for (i = 0; i < 5; i++){
      (*(p_realloc + i)) = i;
      printf("p_realloc[%d] = %d(after malloc(5))\n", i, (*(p_realloc + i)));
    }
  }
 
  printf("realloc example.\n");
 
  p_realloc = (int *)realloc(p_realloc, sizeof(int) * 10);
 
  if (p_realloc != NULL){
    for (i = 0; i < 10; i++){
      (*(p_realloc + i)) = i;
      printf("p_realloc[%d] = %d(after realloc(10))\n", i, (*(p_realloc + i)));
    }
  }
 
  free(p_realloc);
  p_realloc = NULL;
 
  return 0;
 
}