在C ++中将uint8_t数组转换为字符串以在一行中打印

Question

I have the task print an array of uint8_t in one line and using the given log function which is print each message in one line. So, I think I must merge every element in a string and print. I try to use std::stringstream

uint8_t array[512];
std::stringstream ss;
for (int i = 0; i < array_len; i++)
{
    ss << "0x" << std::hex << array[i] << ", ";
}
log_given_print("%s", ss.str().c_str()); // in fact you can replace by printf

It seems to work well. But today, I get the strange log:

0xETX, 0xSOH, 0x%, 0xN, 0x

I checked the ascii table https://www.asciitable.com/ and see that it is some bytes like 0x01, 0x03. I think the problem is %s , normally, I used %x to print each element of array.

How can I fix this problem?

Answer 1

When using the formatted output operator << , it will print characters as characters. You need to convert the values to eg unsigned to be able to print its actual integer value:

ss << "0x" << std::hex << static_cast<unsigned>(array[i]) << ", ";