c - gtree 中的值错误

Question

我正在尝试使用来自glib的gtree。 在像这样迭代时，我在 s 变量中得到错误的值(始终为 0):

gboolean iter_all(gpointer key, gpointer value, gpointer data) {
  int *s =  (int *)value;
  printf("\n%s%d \n", (char *)key, *s);
  return FALSE;
} 

GTree* t = g_tree_new((GCompareFunc)g_ascii_strcasecmp);
readFilec(t);
g_tree_foreach(t, (GTraverseFunc)iter_all, NULL);

我这样设置树:

void readFilec(GTree *tree)
{
  FILE *fp = fopen("cfg/file.csv", "rb" );
  char * line = NULL;
  size_t len = 0;
  ssize_t read;

  if (fp == NULL)
  exit(EXIT_FAILURE);
  char *p1;
  int  p2;
  while ((read = getline(&line, &len, fp)) != -1)
  {
    printf("%s", line);
    p1 = strtok(line, "|");
    p2 = (int)atoi(strtok(NULL, "|"));
    g_tree_insert(tree,(gpointer ) g_strdup(p1), (gpointer )  &p2);

    printf("-%s%d ", p1, p2);

  }

  if (line)
  free(line);
  //exit(EXIT_SUCCESS);

}

我读到的文件如下所示:

cfg/file.csv
AA1.E|1 
AA2.E|2

Answer 1

评论已经指出了问题(您正在将指向本地堆栈变量的指针插入到树中)，但仍然存在一些不太严重的问题。当在GTree中存储int时，最好直接将其用作指针值，例如:

gboolean iter_all(gpointer key, gpointer value, gpointer data) {
    int s =  (int) value;
    printf("\n%s%d \n", (char *)key, s);
    return FALSE;
} 
...
g_tree_insert(tree, (gpointer) g_strdup(p1), (gpointer) p2);

为了避免内存泄漏，您还需要指定一个销毁函数来释放字符串键:

GTree* t = g_tree_new_full((GCompareFunc) g_ascii_strcasecmp,
                           NULL, g_free, NULL);