字符的HEX字符串转换

Posted 2022-05-31 coding码场

1 byte数字转成HEX格式很简单，用sprintf就行，%02x格式输出到指定buffer即可，从字符要转回来成1byte数字要稍微转化一下。

unsigned char hex2int(char c)

    if (c >= '0' && c <= '9')
        return (unsigned char )(c - 48);
    else if (c >= 'A' && c <= 'F')
        return (unsigned char )(c - 55);
    else if (c >= 'a' && c <= 'f')
        return (unsigned char )(c - 87);
    else
        return 0;
   

 
void hex2str(char *hex, char *str)

     int i = 0 ;
     for (int j = 0; j < strlen(hex) - 1 ;)
        unsigned char a = hex2int(hex[j++]);
        unsigned char b = hex2int(hex[j++]);
        str[i++] = (char)(a*16 + b);
   
    str[i] = '\\0';