这个结构体中的值出了什么问题？

Question

对

C

相对较新，并且很容易承认有些事情我认为我理解，但可能不理解所有细微差别。这是从我编写的一个更复杂的程序中提取的 MWE。它编译并运行良好，但测试表明

ev->pin

的值最初是正确的，但在不相关的函数调用后不正确（在代码中查找 ??? ） 看起来内存不知何故被踩踏，但我无法弄清楚发生了什么事。

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#define SCAN_EVENT_COUNT 5
#define PIN_ASSIGNMENTS {7, -1, 1, 13, 4}
#define EVENT_NAMES "first-second-third-fourth-fifth"

void init_scan_events();
int parse_string(char pInputString[],
                 char *Delimiter,
                 char *pToken[]);

struct scan_events
{
  char event_names[31];
  char *pEvent[SCAN_EVENT_COUNT];
  int pin[SCAN_EVENT_COUNT];
};

int main(void)
{
  init_scan_events();
  return (0);
}

/**
 * the following function from https://stackoverflow.com/a/2091906/633251
 * Note that `strtok` expects a `char * string` and `char * delimiter` as arguments.
 **/

int parse_string(char pInputString[],
                 char *Delimiter,
                 char *pToken[])
{
  int i = 0;
  pToken[i] = strtok(pInputString, Delimiter); // get first token
  i++;
  while ((pToken[i] = strtok(NULL, Delimiter)) != NULL) // get the rest of the tokens
  {
    i++;
  }
  return i;
}

void init_scan_events()
{
  char en[] = EVENT_NAMES;
  int en_size = strlen(en);
  int size = SCAN_EVENT_COUNT;
  int pin[] = PIN_ASSIGNMENTS;

  int token_count = 0;
  char *Delim = "-";
  int i;

  struct scan_events *ev = malloc(sizeof(struct scan_events));
  if (ev == NULL)
  {
    printf("Allocation failed\n");
  }

  for (int i = 0; i < en_size; i++) // copy EVENT_NAMES
  {
    ev->event_names[i] = en[i];
  }

  for (int i = 0; i < size; i++) // copy PIN_ASSIGNMENTS
  {
    ev->pin[i] = pin[i];
  }

  for (int i = 0; i < size; i++)
  {
    printf("% d ", ev->pin[i]); // ??? inspect pin values: correct!
  }
  printf("\n");

  token_count = parse_string(ev->event_names, Delim, ev->pEvent); // tokenize EVENT_NAMES

  for (int i = 0; i < size; i++)
  {
    printf("% d ", ev->pin[i]); // ??? check pin values: corrupted!
  }
  printf("\n");

  free(ev);
}

Answer 1

这是

pToken[5] = ...

的缓冲区溢出。