将长动态字符串拆分为 c 中的字符串数组

Question

I'm pretty new to C and can figure out why this function doesn't work consistently whatsoever:

char **splitString(char *string) {
    char *token = strtok(string, ","), **finalValue = NULL, **temp = NULL;
    size_t wordIndex = 0;
    while (token != NULL) {
        temp = realloc(finalValue, sizeof(char *));
        if (!temp) {
            freeArray(finalValue);
            finalValue = NULL;
            break;
        }
        temp[wordIndex] = malloc((strlen(token)+1)*sizeof(char));
        if (temp[wordIndex] == NULL) {
            freeArray(finalValue);
            finalValue = NULL;
            break;
        }
        strcpy(temp[wordIndex], token);
        printf("%s\n", temp[wordIndex]);
        finalValue = temp;
        printf("%s\n", finalValue[wordIndex]);
        wordIndex++;
        token = strtok(NULL, ",");
    }
    return finalValue;

It receives a string separated by commas and its supposed to split them into different strings, all of which were created via `malloc`/`realloc`.

Answer 1

The problem is here: temp = realloc(finalValue, sizeof(char *)); reallocates for a single pointer. You should write:

temp = realloc(finalValue, (wordIndex + 2) * sizeof(char *));

You should also set a NULL pointer at the end of the finalValue array to mark the end of this array as the number of entries is not returned by the function in any other way.

Also note that the allocated strings are not freed when realloc() or malloc() fails.

Finally, you should not use strtok() because it modifies the source string. An alternative approach with strspn() , strcspn() and strndup() is recommended.