我找到了将字符串转换为 pdu 的代码（septet to octet char）
#include <iostream>
#include <sstream>
#include <iomanip>
#include <string>
std::string toPDU(const std::string &original)
// Converts an ANSI string to PDU format
{
if (original.empty()) {
// Empty string -> nothing to do
return original;
}
std::string result;
// Reserve enough space to hold all characters
result.reserve((original.length() * 7 + 7) / 8);
// Variables for holding the current amount of bits to copy from the next character
size_t bitshift = 1, mask = 0x01;
unsigned char curr = original[0]; //->> ERROR !!!!!!!!!!!!!!!!!
for (size_t i = 1; i < original.length(); ++i) {
if (bitshift != 0) {
// If bitshift is 0, then curr will be 0, so in effect we should skip a character
// So only do the following when bitshift different from 0
// Add the low bits (using the mask) to the left of the current character
curr += (static_cast<unsigned char>(original[i]) & mask) << (8 - bitshift);
result += curr;
}
// Remember the remaining bits of this character so that we can add them later
curr = (original[i] & ~mask) >> bitshift;
// Cycle bitshift through 0-7 (could also be written as bitshift = (bitshift + 1) mod 8)
bitshift = (bitshift + 1) & 0x7;
// Set the mask to have all bitshift lower bits set
// e.g. bitshift = 3, then mask = 0x07
// bitshift = 5, then mask = 0x1F
// bitshift = 7, then mask = 0x7F
mask = (1 << bitshift) - 1;
}
result += curr;
return result;
}
std::string toHEX(const std::string &original)
// Converts a string to the hexadecimal representation of its characters
{
std::ostringstream os;
os << std::hex << std::uppercase;
for (size_t i = 0; i < original.length(); ++i) {
os << static_cast<unsigned int>(static_cast<unsigned char>(original[i])) << " ";
}
return os.str();
}
int main()
{
using namespace std;
cout << toHEX(toPDU("hellohello")) << endl;
return 0;
}
并在 Visual Studio 2012 出现此错误：
错误 C2014：预处理器命令必须以第一个非空白开始
我是 C++ 新手，任何人都可以解释为什么会发生此错误？谢谢。