二进制字节字符转换为ASCII的方法

/**  
* @brief 该函数实现了将二进制字节数据转换为可打印ASCII码字符串 
* @param[in] pSrc 源数据指针
* @param[in] nSrcLength 源数据长度
* @param[out] pDst 目标字符串指针
* @return 目标字符串长度

* @author [e-mail]
*      http://blog.csdn.net/rabbit729
* @version 1.0 
* @date 2009-02-25
*/

#include <assert.h>
#include <iostream>
using namespace std;

int BinaryBytes2String1(const unsigned char* pSrc, unsigned int nSrcLength, char* pDst)
{
    if ( pSrc == 0 || pDst == 0 )
        return 0;

    char* p = pDst;

    for ( unsigned i = 0; i < nSrcLength; i++ )
    {
        *p = (pSrc[i] >> 4) & 0x0f;
        *p += *p < 10 ? 0x30 : (0x61 - 10);
        p++;

        *p = pSrc[i] & 0x0f;
        *p += *p < 10 ? 0x30 : (0x61 - 10);
        p++;
    }

    *p = '/0';
    return nSrcLength * 2;
}

int BinaryBytes2String2(const unsigned char* pSrc, unsigned int nSrcLength, char* pDst )  
{  
    if ( pSrc == 0 || pDst == 0 )
        return 0;

    const char tab[]="0123456789abcdef";  

    for(int i=0; i<nSrcLength; i++)  
    {   
        *pDst++ = tab[*pSrc >> 4]; 
        *pDst++ = tab[*pSrc & 0x0f];
        pSrc++;  
    }  

    *pDst = '/0';  

    return nSrcLength * 2;  
}  

int BinaryBytes2String3(const unsigned char* pSrc, int nSrcLength, char* pDst)
{
    if ( pSrc == 0 || pDst == 0 )
        return 0;

    for (int i = 0; i < nSrcLength; i++)
    {
        sprintf(pDst, "%02x", *pSrc);
        pDst++;
        pDst++;
        pSrc++;
    }
    *pDst = '/0';

    return nSrcLength * 2;
}

void main(void)
{
    unsigned char test[3] = {0x23, 0xa4, 0xB7};
    char result[7];
    memset(result, 0, 7);

    BinaryBytes2String1(test, 3, result);
    cout<<result<<endl;

    BinaryBytes2String2(test, 3, result);
    cout<<result<<endl;

    BinaryBytes2String3(test, 3, result);
    cout<<result<<endl;
}
文章出处：飞诺网(http://dev.firnow.com/course/3_program/c++/cppjs/20090403/164090.html)