16进制打印内存的内容

test.c

/* 0000000: 0000 0000 0000 0000 0000 0000 0000 0000  ................ */
void hexdump(const char *buff, int blen)
{
	static char hexmap[] = "0123456789abcdef";
	int offset, len, count, hexoff;
	unsigned char str[58], c;
	str[57] = 0, str[40] = ' ';
	for (offset = 0, len = 16; offset < blen; offset += 16) {
		if (blen - offset < 16) {
			len = blen - offset;
			memset(str, ' ', 57);
		}
		for (count = 0, hexoff = 0; count < len; count++) {
			c = *(unsigned char *)(buff + offset + count);
			str[hexoff++] = hexmap[(c >> 4) & 0xf];
			str[hexoff++] = hexmap[c & 0xf];
			if (count % 2)
				str[hexoff++] = ' ';
			str[41 + count] = isprint(c) ? c : '.';
		}
		printf("%07x: %s\n", offset, str);
	}
}