c - strlen 指针与数组

Question

我在使用指针与静态数组时遇到了一些问题。我陷入了这个错误:

void LZWCompress(FILE* file, char minCodeSize, char *pixels, int area)
{

int k = ++minCodeSize, i, len = DEFAULT, jump = 0, dicLen;
lzwDict *dictionary = NULL, *s, *temp;

char *curr, next[2], *buffer;

dicLen = initializeDictionary(&dictionary, minCodeSize);
for(i = 0; i < area; i++)
{
    if(dicLen + 1 >= pow(2, k))
        k = k + 1;

    curr = (char*) malloc(sizeof(char) * DEFAULT);
    curr[0] = pixels[i];
    curr[1] = '\0';

    printf("strlen %lu  %s\n", strlen(curr)); ### strlen(curr) = 0 ? WH ? ###
    if((i + 1) > area)
    {
        //outputs curr
        break; 
    }


    len = len + 1;
    jump = jump + 1;

    next[0] = pixels[i + jump];
    next[1] = '\0';

    buffer = (char*) malloc(sizeof(char) * len);
    printf("%lu %lu %lu \n", strlen(buffer), strlen(curr), strlen(next)); ### prints out "0 0 1" ###

(...) 代码继续，由于这个问题我得到了 Abort Trap

    buffer = strcat(curr, next);
    HASH_FIND_STR(dictionary, buffer, s);

    if(s)
    {
        printf("YOLO\n");
        do{
            jump = jump + 1;

            if(i + jump >= area)
                exit(-1);

            printf("%d \n", len);
            curr = (char*) realloc(curr, sizeof(char) * len); ### Here i get Abort Trap 6 ###

(...) 代码继续

为什么我使用数组 (next[2]) 而不是使用指针 (*curr, *buffer) 时得到预期的结果。

如果相关的话，我正在使用 OSX Yosemite。

Answer 1

根据strlen doc :

The length of a C string is determined by the terminating null-character: A C string is as long as the number of characters between the beginning of the string and the terminating null character (without including the terminating null character itself).

This should not be confused with the size of the array that holds the string.

如果 pixels[i] 等于 0，则 strlen(next) 将为 0。