分段错误11，尽管大量的内存分配

Question

我遇到了一个奇怪的错误。当我编译我的代码时，它会给我以下消息：

%i?? 
[R? 
R? 
? 
Desktop/prog2 
Terminal 
51/sls2t0f16cd4dzl3640n4p2w0000gn/T/ 
private/tmp/com.apple.launchd.AJrzeyltFv/Render 
ION=343.6 
ER=Frank 
Listeners 
in:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/git/bin 
ank 
E=/Users/Frank 
nk/Desktop/prog2 

Segmentation fault: 11 
logout 

我知道这是由于内存问题。然而，我给字典2与原始字典一样的内存，所以为什么它不能编译整个列表？

这里是我的代码（我知道这是在长边一点点，但我觉得这是所有必要的传达是怎么回事）：

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

struct entry 
{ 
    char word[15]; 
    char definition[50]; 
}; 


void dictionarySort(struct entry dictionary[]) { 
    int i, j, k, word1, word2, dict2Length = 1; 
    bool bnf = false; 
    struct entry dictionary2[100] = {{}}; 

    for (i = 0; i <= strlen(&dictionary->word[0]); i++) { 
     strcpy(&dictionary2[0].word[i], &dictionary[0].word[i]); 
    } 


    i = 0; 
    word1 = 1; 
    word2 = 0; 



    while (isalpha(dictionary[word1].word[0])) { 

     while (i <= strlen(&dictionary->word[word1])) { 
      //printf("%c", dictionary[word1].word[i]); 
      if (dictionary[word1].word[i] == dictionary2[word2].word[i]) { 
       i++; 
       bnf = false; 
      } 
      else if (dictionary[word1].word[i] < dictionary[word2].word[i]) { 
       //insert section to prevent back-and-forth cycling 
       if (bnf == false) { 
        word2--; 
        bnf = true; 
       } 
       else { //(dictionary[word1].word[i] < dictionary[word2].word[i]) 
        //open up new index by moving everything above up one, insert at word 
        for (j = dict2Length; j > word2; j--) { 
         //word 
         for (k = 0; k <= strlen(&dictionary2->word[0]); k++) { 
          strcpy(&dictionary2[j+1].word[k], &dictionary2[j].word[k]); 
         } 
         //definition 
         for (k = 0; k <= strlen(&dictionary2->word[0]); k++) { 
          strcpy(&dictionary2[j+1].definition[k], &dictionary2[j].definition[k]); 
         } 
        } 

        //for (k = 0; k < strlen(&dictionary1->word[word1])) 
        for (k = 0; k < strlen(dictionary[word1].word); k++) { 
         strcpy(&dictionary2[word2].word[k], &dictionary[word1].word[k]); 
        } 
        for (k = 0; k < strlen(dictionary[word1].definition); k++) { 
         strcpy(&dictionary2[word2].definition[k], &dictionary[word1].definition[k]); 
        } 
        dict2Length++; 
        break; 
       } 
      } 
      else { 
       //insert section to prevent back-and-forth cycling 
       if (bnf == false) { 
        word2++; 
        bnf = true; 
       } 
       else { //(dictionary[word1].word[i] < dictionary[word2].word[i]) 
        //open up new index by moving everything above up one, insert at word 
        for (j = dict2Length; j > word2; j--) { 
         //word 
         for (k = 0; k <= strlen(&dictionary2->word[0]); k++) { 
          strcpy(&dictionary2[j+1].word[k], &dictionary2[j].word[k]); 
         } 
         //definition 
         for (k = 0; k <= strlen(&dictionary2->word[0]); k++) { 
          strcpy(&dictionary2[j+1].definition[k], &dictionary2[j].definition[k]); 
         } 
        } 

        for (k = 0; k < strlen(dictionary[word1].word); k++) { 
         strcpy(&dictionary2[word2].word[k], &dictionary[word1].word[k]); 
        } 
        for (k = 0; k < strlen(dictionary[word1].definition); k++) { 
         strcpy(&dictionary2[word2].definition[k], &dictionary[word1].definition[k]); 
        } 
        dict2Length++; 
        break; 
       } 
      } 
     } 
     word1++; 
    } 


    word2 = 0; 

    for (i = 0; i < dict2Length; i++) { 
     printf ("%s\n", dictionary2[i].word); 
    } 

} 

int main (void) { 
    struct entry dictionary[100] = 
    {{"aerie", "a high nest"}, 
    {"abyss", "a bottomless pit"}, 
    {"ahoy", "a nautical call of greeting"}, 
    {"addle", "to become confused"}, 
    {"aardvark", "a burrowing African mammal"}, 
    {"agar", "a jelly made of seaweed"}, 
    {"acumen", "mentally sharp; keen"}, 
    {"aigrette", "an ornamental cluster of feathers"}, 
    {"affix", "to attach"}, 
    {"ajar", "partially opened"}}; 
    dictionarySort(dictionary); 
} 

Answer 1

看起来你在计算字典长度时遇到了麻烦。当你运行它时，它说长度就像1701996321一样，这看起来要比它应该高得多。然后，在最后一个循环中，直到您打印单词的最后，您可能会跳出字典的界限。注释掉那个printf，你会看到错误消失了。我会先看看dict2Lenght。

for (i = 0; i < dict2Length; i++) { 
    printf ("%s\n", dictionary2[i].word); 
} 

Answer 2

此行有索引后到前

strcpy(&dictionary2[0].word[i], &dictionary[0].word[i]);  

应该

strcpy(&dictionary2[i].word[0], &dictionary[i].word[0]); 

甚至更​​好

strcpy(dictionary2[i].word, dictionary[i].word); 

此外，您的循环for (i...)基于strlen(&dictionary->word[0])。您是否应该将数组条目数作为参数传递给dictionarySort()？就目前而言，循环是基于第一个字典条目的长度。我不得不通过调试排序。这太可怕了。只需使用qsort()。

Answer 3

使用qsort

void dictionarySort(struct entry dictionary[]) { 
    struct entry dictionary2[100] = {{"",""}}; 
    int i, n; 

    for (i = 0; i < 100 && dictionary[i].word[0] != '\0'; ++i){ 
     dictionary2[i] = dictionary[i]; 
    } 
    n = i; 

    qsort(dictionary2, n, sizeof(*dictionary2), strcmp); 

    for (i = 0; i < n; ++i) { 
     printf ("%s\n", dictionary2[i].word); 
    } 
}