字元串轉數字簡單代碼實現

#include <stdio.h>

#define u8 unsigned char
static const int MAC_LENGTH = 6;

static u8 char1Tonum(u8 ch)
{
    if((ch>='0')&&(ch<='9'))
        return ch - '0';
    else if ((ch>='a')&&(ch<='f'))
        return ch - 'a' + 10;
    else if ((ch>='A')&&(ch<='F'))
        return ch - 'A' + 10;
    else
     return 0xff;
}

//簡單的把字元串轉為數字 (比如把MAC地址轉為6個數字)
static u8 char2Tonum(u8 hch, u8 lch)
{
    return ((char1Tonum(hch) << 4) | char1Tonum(lch));
}

static void charToArray(u8* array,u8* stringBuf)
{
    for(int i =0,j=0;i<MAC_LENGTH;i++,j+=2)
    {
        array[i] = char2Tonum(stringBuf[j],stringBuf[j+1]);
        printf("0x%x\n",array[i]);
    }
}

int main()
{
    u8 buf[MAC_LENGTH] = {0};
    u8 bufMac[MAC_LENGTH*2+1] = "112233445566";

    charToArray(buf,bufMac);

/*    for(int i =0,j=0;i<MAC_LENGTH;i++,j+=2)
    {
        buf[i] = char2Tonum(bufMac[j],bufMac[j+1]);
        printf("0x%x\n",buf[i]);
    }
*/

    return 0;
}/* 何問起 hovertree.com */

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