我正在尝试读入一个文本文件,并逐字将其字符串添加到链接列表中。我是C语言新手,不太懂指针。我已经有几个不同的错误,只是搞乱了它,但现在我得到的分割错误在我的插入方法。这真的很令人沮丧。有人能解释一下我做错了什么吗?

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

struct listNode {  /* self-referential structure */
   char data[50];
   struct listNode *nextPtr;
};

typedef struct listNode LISTNODE;
typedef LISTNODE *LISTNODEPTR;

void insert(LISTNODEPTR *, char[]);
void printList(LISTNODEPTR);
char fpeek(FILE *);

main() {

    FILE *fptr;
    char file_name[20];
    int nrchar = 0;
    LISTNODEPTR startPtr = (struct listNode *) malloc(sizeof(struct listNode));
    char word[50];
    char c;
    int i;

    printf("What is the name of the file in which the text is stored?\n");
    scanf("%s",file_name);
    //  printf("Type the number of characters per line");
    //scanf("%d", &nrchar);
    fptr = fopen(file_name,"r");
        while(fpeek(fptr) != EOF) {
      i = 0;
      while(fpeek(fptr) != ' '){
        word[i] = fgetc(fptr);
        i++;
        printf("%d", i);
      }
      word[strlen(word)] = '\0';
      insert(&startPtr, word);
      word[0] = '\0';
    }
    fclose(fptr);
    printList(startPtr);


return 0;
}

    /* Insert a new value into the list in sorted order */
    void insert(LISTNODEPTR *sPtr, char value[])
    {
      LISTNODEPTR newPtr, currentPtr;

      newPtr = malloc(sizeof(LISTNODE));
      strcpy(newPtr->data, value);
      newPtr->nextPtr = NULL;
      currentPtr = *sPtr;

      while(currentPtr != NULL){
        currentPtr = currentPtr->nextPtr;
      }
      currentPtr->nextPtr = newPtr;

    }


    /* Return 1 if the list is empty, 0 otherwise */
    int isEmpty(LISTNODEPTR sPtr)
    {
       return sPtr == NULL;
    }

    /* Print the list */
    void printList(LISTNODEPTR currentPtr)
    {
       if (currentPtr == NULL)
          printf("List is empty.\n\n");
       else {
          printf("The list is:\n");

          while (currentPtr != NULL) {
             printf("%s --> ", currentPtr->data);
             currentPtr = currentPtr->nextPtr;
          }

          printf("EOF\n\n");
       }
    }

    char fpeek(FILE *stream) {
        char c;
        c = fgetc(stream);
        ungetc(c, stream);
        return c;
    }

最佳答案

首先,检查库函数(如fopen()等)的返回值。
其次,看西蒙斯的回答。
第三,在这个循环之后:

  while(currentPtr != NULL){
    currentPtr = currentPtr->nextPtr;
  }
  currentPtr->nextPtr = newPtr;

currentPtr为空,因此currentPtr->nextPtr = newPtr;将取消对空指针的引用。
也许有点像
  while(currentPtr && currentPtr->nextPtr) {
    currentPtr = currentPtr->nextPtr;
  }
  currentPtr->nextPtr = newPtr;

更多的是你想要的。
最后,
char fpeek(FILE *stream) {
    char c;
    c = fgetc(stream);
    ungetc(c, stream);
    return c;
}

应该是
int fpeek(FILE *stream) {
    int c;
    c = fgetc(stream);
    ungetc(c, stream);
    return c;
}

总的来说
char fpeek(FILE *);

应该是
int fpeek(FILE *);

08-16 21:56