Question

我正在尝试将char word[50]数组复制到char **wordlist双指针，然后realloc(wordlist, (numwords+1)*sizeof(char*))将单词列表的大小再增加一char*来保持下一个word。

我不断收到*** glibc detected *** ./program: realloc(): invalid next size错误

我将其声明为wordlist = realloc(wordlist, (numwords+1)*sizeof(char*))

void outFile(char *argv[], char **wordlist)
  {
      if((inFilePtr = fopen(argv[2], "r")) != NULL)
      {
          if((outFilePtr = fopen(endOfFile, "w")) != NULL)
          {
              while((c = fgetc(inFilePtr)) != EOF)
              {
                  if(!(isspace(c)))
                  {
                      word[wordIndex] = c;
                      wordIndex++;
                      rowLim++;
                  }
                  if(isspace(c))
                  {
                      wordIndex = 0;
                      if(rowLim < limit)
                      {
                          rowLim++;
                          strcat(text[rowNum], word);
                          strcat(text[rowNum], " \0");
                          wordlist[numwords] = strdup(word);
                          /*strcat(wordlist[numwords], "\n\0");*/
                          memset(word, 0, 50);
                          prev = rowLim;
                          wordlist = realloc(wordlist, (numwords + 1)*sizeof(char*));
                          numwords++;
                      }
                      else
                      {
                          strcat(text[rowNum], "\n\0");
                          printf("text[%d] = %s",rowNum, text[rowNum]);
                          fputs(text[rowNum], outFilePtr);
                          rowNum++;
                          strcat(text[rowNum], word);
                          strcat(text[rowNum], " \0");
                          /*strcat(wordlist[numwords], word);
                          strcat(wordlist[numwords], "\n\0");
                          wordlist = realloc(wordlist, (numwords + 1)*sizeof(char*));*/
                         numwords++;
                         memset(word, 0, 50);
                         rowLim = rowLim - prev;
                     }
                     wordIndex = 0;
                 }
             }
             strcat(text[rowNum], "\n\0");
             printf("text[%d] = %s",rowNum, text[rowNum]);
             fputs(text[rowNum], outFilePtr);
             fclose(outFilePtr);
         }

Answer 1

您在分配空间之前尝试使用空间：

wordlist[numwords] = strdup(word);
wordlist = realloc(wordlist, (numwords + 1)*sizeof(char*));
numwords++;

相反，首先分配空间：

wordlist = realloc(wordlist, (numwords + 1)*sizeof(char*));
wordlist[numwords] = strdup(word);
numwords++;

NB。正如iharob所述，如果您希望能够从内存不足中恢复，那么realloc的返回值应存储在单独的变量中，直到您确认它不是NULL为止。

您的所有\0都是多余的。字符串文字是字符串：例如"\n"表示已经{ '\n', '\0' }。

通过在text[rowNum]中写入太多内容，无法从此代码中判断出是否导致缓冲区溢出。我建议重新设计这段代码，以确保它永远不会溢出。

C：双指针Realloc问题

1 个答案: