[C++知识库]十六进制格式打印char*

C++ Builder

??今天调试GUI程序，需要将网络接收的数据流（char*）以十六进制的格式打印到日志窗口上。

String PrintHex(char *data, int len)
{
		char alphabet[16]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
		String s;
		for (int i=0; i<len; i++) {
				int l = (int)(data[i]&0x0f);
				int h = (int)(data[i]>>4)&0x0f;
				s += alphabet[h];
				s += alphabet[l];
				s += " ";
		}
		return s;
}

在后来的调试过程中发现当传输的数据比较复杂的时候，这样直接的打印字节序列很难定位到某个具体元素在序列中的位置，为此在前面程序的基础上添加了显示地址的功能。

String PrintHex(char *data, int len)
{
	char alphabet[16]={'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
	String s;
	int l,h;
	for (int i=0; i<len; i++) {
		if (i % 8 == 0) {
			s += "\r\n";
			char start = (i/8)*8;
			l = (int)(start&0x0f);
			h = (int)(start>>4)&0x0f;
			s += alphabet[h];
			s += alphabet[l];

			s += "~";

			char end = (i/8+1)*8-1;
			l = (int)(end&0x0f);
			h = (int)(end>>4)&0x0f;
			s += alphabet[h];
			s += alphabet[l];

			s += ": ";
		}
		l = (int)(data[i]&0x0f);
		h = (int)(data[i]>>4)&0x0f;
		s += alphabet[h];
		s += alphabet[l];
		s += " ";
	}
	return s;
}

以下是调试过程中一个输出案例。

00~07: 11 42 00 01 a3 65 00 00 
08~0f: 00 00 00 40 59 40 00 00 
10~17: 00 00 00 c0 59 40 00 00 
18~1f: 00 00 00 80 59 40 00 00 
20~27: 00 00 00 40 5a 40 6a 00 
28~2f: 00 00 00 00 00 c0 5a 40 
30~37: 00 00 00 00 00 00 26 40 
38~3f: 22 00 00 00 0d 0e 07 fb 
40~47: 0d 0a