获取unsigned char*的正确方法是什么？

Question

我的代码给出了我期望的unsigned char指针的不同长度.我认为我应该为pph和pphChar获得12(或13)或0(或1).我的问题是什么？当我重复跑步时,每次长度和长度都有不同的结果.

我怎样才能获得pph的长度？

我需要在末尾加上'\n'来确定长度吗？

我使用VS2010,XP和C++.

#include "stdafx.h"
#include <stdlib.h>
#include <Windows.h>
#include <stdio.h>
#include <tchar.h>

typedef unsigned char uint8_t;

int _tmain(int argc, _TCHAR* argv[])
{

int length;
int len = 13;
uint8_t *phh;
char * phhChar;

printf("assigned mem %d\n", sizeof(unsigned char)*len);
phh = (unsigned char *) malloc(sizeof(unsigned char)*len);
phhChar = (char *) malloc(sizeof(char)*len);

phh[0] = (unsigned char) '1';
phh[1] = (unsigned char) '2';
phh[2] = (unsigned char) '3';
phh[3] = (unsigned char) '4';
phh[4] = (unsigned char) '5';
phh[5] = (unsigned char) '6';
phh[6] = (unsigned char) '7';
phh[7] = (unsigned char) '8';
phh[8] = (unsigned char) '9';
phh[9] = (unsigned char) '0';
phh[10] = (unsigned char) '1';
phh[11] = (unsigned char) '2';
phh[12] = (unsigned char) '\n';

phhChar[0] = (char) '\n';

printf("size of char %d\n", sizeof(unsigned  char));
length =  strlen((const char*)phh);
int oneLength = strlen((const char*)phhChar);

printf("len %d\n", length );
printf("onelebgth %d\n", oneLength);

OUTPUT

指定的纪录13

char 1的大小

len 32 - 每次都不同

oneLength 32 - 每次都不同

Answer 1

您缺少\0字符串末尾的空终止符,因此strlen无法知道unsigned char *结束的位置.

实际上,它一直在计算你所设置的地址到最后一个字符,直到达到a \0.