c - 这是什么意思，我应该如何为大文件解决这个问题？ (malloc_error_break)

Question

问题:

此代码示例搜索单词并计算单词数，以及具有 1000 行的较大 txt 文件的唯一单词数我收到错误，有什么想法吗？

错误:

week7_14(43430,0x1087085c0) malloc: *** error for object 0x696c617274737561: pointer being freed was not allocated
week7_14(43430,0x1087085c0) malloc: *** set a breakpoint in malloc_error_break to debug

---

代码示例:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXLEN 100
#define MAXWORDS 1000

int findWord(char *word[], char *temp, int index) {
    for (int i=0; i<index; i++)
    {
        if (strcmp(word[i], temp) == 0) // found the word
            return 1;
    }
    return 0; // cannot find word }

int main(int argc, char **argv) {
    char filename[MAXLEN];
    char *words[MAXWORDS] = {NULL};
    char temp[MAXLEN];
    int wordCount = 0;
    int uniqueWordCount = 0;
    int i = 0;
    // read in the filename
    printf("insert a file name: (eg. test.txt)\n");
    scanf("%s", filename);
    FILE *fp = fopen(filename, "r");
    if (fp == NULL)
    {
        printf("Cannot open file %s\n", filename);
        return 1;
    }

    while ((fscanf(fp, "%s", temp) == 1) && uniqueWordCount<MAXWORDS)
    {
        wordCount++; // update total number of words
    // find word in words array
        if (!findWord(words, temp, uniqueWordCount))
        {
            words[uniqueWordCount] = calloc(strlen(temp)+1,
                                            sizeof(char));
            if (words[uniqueWordCount] == NULL)
            {
                printf("calloc failed to allocate memory\n");
                return 1;
            }
            strcpy(words[uniqueWordCount], temp);
            uniqueWordCount++; // update number of unique words
        }
    }
    fclose(fp);
    while (i<uniqueWordCount)
    {
        free(words[uniqueWordCount]);
        i++;
    }
    printf("Total number of words = %d\n", wordCount);
    printf("Number of unique words = %d\n", uniqueWordCount);
    return 0; }

有效的示例文本文件 (test.txt):

Any girl jumped over one boy.
Some car skipped to some boy.
One town drove over the town.
Any town ran under some dog.
Some girl drove to a town.
The boy walked under any town.
A town jumped over any car.
Any boy jumped from a car.
A dog ran over a boy.
A girl ran to some car.
A car ran under the girl.
The car ran on any town.
One dog walked under any dog.
A car jumped on some town.
A boy ran to a boy.
The dog drove over a boy.
A boy jumped over the car.
Some car drove on some girl.
One boy drove under some girl.
A girl walked over some dog.

输出:

insert a file name: (eg. test.txt)

test.txt

Total number of words = 120

Number of unique words = 30

Answer 1

您有几个问题需要解决，(1)，您缺少右大括号:

int findWord(char *word[], char *temp, int index) {
    for (int i=0; i<index; i++)
    {
        if (strcmp(word[i], temp) == 0) // found the word
            return 1;
    }
    return 0; // cannot find word }
}   /* missing closing brace */

(2) 你有一个错字并且试图释放 words[uniqueWordCount] 而不是 words[i]，例如

    for (i = 0; i<uniqueWordCount; i++) /* loop over each word in words */
        free(words[i]);    /* free words[i], not words[uniqueWordCount] */

(注意尝试释放 words[uniqueWordCount] 会产生错误，因为 uniqueWordCount 是最后分配的指针之后的一个)

最后，您应该使用 int main (void)，因为既没有使用 int argc 也没有使用 char **argv。