C语言 从非空函数中释放内存

Question

我在释放内存时遇到问题：

我得到的输出是这样的：

==11073== 1,000 bytes in 1 blocks are definitely lost in loss record 5 of 5
==11073==    at 0x4A06A2E: malloc (vg_replace_malloc.c:270)
==11073==    by 0x400B38: userInput (program.c:80)
==11073==    by 0x400DFD: playGame (program.c:150)
==11073==    by 0x4012E9: main (program.c:298)

我使用的变量是在 main 之外定义的输入和答案：

char *answer;
char *input;

我在 main 中使用的变量"答案"是这样的：

line 150    answer = userInput();

函数是这样的：

char* userInput()
{
  printf ("> ");
  input = malloc (sizeof(char) * 1000); // THIS is LINE 80
  fgets(input, 1000, stdin);
  //input = realloc(input, strlen(input));
  strtok(input, "n");
  int i = 0;
  while (i < strlen(input))
  {
    input[i] = tolower(input[i]);
    i++;
  }
  if (strcmp(input, "y") == 0 || strcmp(input, "yep") == 0 || strcmp(input, "yeah") == 0
      || strcmp(input, "absolutely") == 0 || strcmp(input, "correct") == 0)
    input = "yes";
  if (strcmp(input, "n") == 0 || strcmp(input, "nope") == 0)
    input = "no";
  return input;
}

Answer 1

你在这里泄漏了内存：

input = "yes";

在这里：

input = "no";

input现在指向字符串文本，它以前指向的内存将丢失。