Question

我正在尝试创建一个函数，它接受一个字符串和一个字符串数组的指针，malloc() char数组的数组，并复制字符串的每个单词。这就是我到目前为止，我认为我很接近，我只是在数组数组上使用malloc()。

int string_parser(char *inp, char **array_of_words_p[])
{
    int CurrentChar = 0;                //Variable Initialization
    char *buffer;                       //Variable Initialization

    /* Allocate memory and check for errors allocating memory */
    //Allocate memory to buffer the size of the input string
    buffer = (char*)malloc(strlen(inp));    
    if (buffer == NULL)
    {
        printf("Error allocating memory..\n");
        return -1;
    }

    /* Move input string into buffer before processing */
    for (CurrentChar = 0; CurrentChar < strlen(inp) + 1; CurrentChar++)
    {   //For every character in input
        if (inp != NULL)                                                    
        {
            //Move input character into buffer
            buffer[CurrentChar] = inp[CurrentChar];     
        }
    }

    /* Convert string into array of words */
    char ** stringbuffer = NULL;        

    //Convert string to array of words
    char *  CurrentWord = strtok_s(buffer, " ", *array_of_words_p);     

    //Variable Initialization
    int numspaces = 0;

    while (CurrentWord)                                                 
    {
        //Allocate memory for size of string
        stringbuffer = (char**)realloc(stringbuffer, sizeof(char**) * ++numspaces); 
        if (stringbuffer == NULL)                                       
        {
            return -1;
        }
        stringbuffer[numspaces - 1] = CurrentWord;

        //Reset Current word to null        
        CurrentWord = strtok_s(NULL, " ", *array_of_words_p);       
    }

    //Reallocate memory to include terminating character
    stringbuffer = (char**)realloc(stringbuffer, sizeof(char**) * (numspaces + 1)); 
    stringbuffer[numspaces] = 0;                                        

    /* Write processed data into returned argument */
    *array_of_words_p = (char**)malloc(sizeof(char**) * (numspaces + 2));           
    memcpy(*array_of_words_p, stringbuffer, (sizeof(char*) * (numspaces + 2))); 

    free(stringbuffer);                                             
    return numspaces;                                                   
}

Answer 1

    //Allocate memory to buffer the size of the input string
    buffer = (char*)malloc(strlen(inp));

输入字符串的大小包含终止\0，因此您需要：

    buffer = malloc(strlen(inp)+1);

    //Convert string to array of words
    char *  CurrentWord = strtok_s(buffer, " ", *array_of_words_p);

将*array_of_words_p滥用于上下文保存变量是不明智的，因为这需要对其进行适当的初始化。更好：

    char *context, *CurrentWord = strtok_s(buffer, " ", &context);
    …
        CurrentWord = strtok_s(NULL, " ", &context);

        //Allocate memory for size of string
        stringbuffer = (char**)realloc(stringbuffer, sizeof(char**) * ++numspaces);

它可能不会受到伤害（由于指针大小相等），但sizeof(char**)严格来说是错误的，因为字符串数组的元素属于{{ 1}}。正确的：

char *

        stringbuffer = realloc(stringbuffer, sizeof (char *) * ++numspaces);
    …
    stringbuffer = realloc(stringbuffer, sizeof (char *) * (numspaces + 1));

您可以免除这种不必要的复制，并通过以下方式替换上述内容来避免访问未分配的内存/* Write processed data into returned argument */ *array_of_words_p = (char**)malloc(sizeof(char**) * (numspaces + 2)); memcpy(*array_of_words_p, stringbuffer, (sizeof(char*) * (numspaces + 2))); free(stringbuffer);：

stringbuffer[numspaces+1]

除此之外，您的功能可以正常工作，可以像：

一样调用

    *array_of_words_p = stringbuffer;

malloc（）表示字符串数组，不能用作希望

1 个答案: