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- 21 Апр 2020
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Бывают случаи, когда нужно ограничить использование программы по времени. Итак, первое, что нам нужно, это найти бесплатный сервер времени:
Теперь главный файл main.cpp:
Как видим, все просто. Идет простая проверка времени с заранее установленным значением. По этому сервису можно заранее установить время в программе, когда должен закончится пробный период:
На этом гайд завершается, всем спасибо. Вот текущий проект:
Пожалуйста, авторизуйтесь для просмотра ссылки.
. сервер на данный момент поддерживает протокол передачи данных http. Именно оно нам и нужно, т.к. этот протокол поддерживает WinSocket. Теперь давайте найдем какую-нибудь библиотеку для работы с сетью. Опять, искать не нужно - эта библиотека называется HTTPRequest, скачать ее можно отсюда:
Пожалуйста, авторизуйтесь для просмотра ссылки.
. Библиотека самая простая и содержит только один заголовочный файл. В общем, файл заголовка HTTPRequest.hpp выглядит так:
C++:
//
// HTTPRequest
//
#ifndef HTTPREQUEST_HPP
#define HTTPREQUEST_HPP
#include <cctype>
#include <cstddef>
#include <cstdint>
#include <algorithm>
#include <functional>
#include <map>
#include <memory>
#include <stdexcept>
#include <string>
#include <system_error>
#include <type_traits>
#include <vector>
#ifdef _WIN32
# pragma push_macro("WIN32_LEAN_AND_MEAN")
# pragma push_macro("NOMINMAX")
# ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
# endif
# ifndef NOMINMAX
# define NOMINMAX
# endif
# include <winsock2.h>
# if _WIN32_WINNT < _WIN32_WINNT_WINXP
char* strdup(const char* src)
{
std::size_t length = 0;
while (src[length]) ++length;
char* result = static_cast<char*>(malloc(length + 1));
char* p = result;
while (*src) *p++ = *src++;
*p = '\0';
return result;
}
# include <wspiapi.h>
# endif
# include <ws2tcpip.h>
# pragma pop_macro("WIN32_LEAN_AND_MEAN")
# pragma pop_macro("NOMINMAX")
#else
# include <sys/socket.h>
# include <netinet/in.h>
# include <netdb.h>
# include <unistd.h>
# include <errno.h>
#endif
namespace http
{
class RequestError final: public std::logic_error
{
public:
explicit RequestError(const char* str): std::logic_error(str) {}
explicit RequestError(const std::string& str): std::logic_error(str) {}
};
class ResponseError final: public std::runtime_error
{
public:
explicit ResponseError(const char* str): std::runtime_error(str) {}
explicit ResponseError(const std::string& str): std::runtime_error(str) {}
};
enum class InternetProtocol: std::uint8_t
{
V4,
V6
};
inline namespace detail
{
#ifdef _WIN32
class WinSock final
{
public:
WinSock()
{
WSADATA wsaData;
const auto error = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (error != 0)
throw std::system_error(error, std::system_category(), "WSAStartup failed");
if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2)
{
WSACleanup();
throw std::runtime_error("Invalid WinSock version");
}
started = true;
}
~WinSock()
{
if (started) WSACleanup();
}
WinSock(WinSock&& other) noexcept:
started(other.started)
{
other.started = false;
}
WinSock& operator=(WinSock&& other) noexcept
{
if (&other == this) return *this;
if (started) WSACleanup();
started = other.started;
other.started = false;
return *this;
}
private:
bool started = false;
};
#endif
inline int getLastError() noexcept
{
#ifdef _WIN32
return WSAGetLastError();
#else
return errno;
#endif
}
constexpr int getAddressFamily(InternetProtocol internetProtocol)
{
return (internetProtocol == InternetProtocol::V4) ? AF_INET :
(internetProtocol == InternetProtocol::V6) ? AF_INET6 :
throw RequestError("Unsupported protocol");
}
#ifdef _WIN32
constexpr auto closeSocket = closesocket;
#else
constexpr auto closeSocket = close;
#endif
#if defined(__APPLE__) || defined(_WIN32)
constexpr int noSignal = 0;
#else
constexpr int noSignal = MSG_NOSIGNAL;
#endif
class Socket final
{
public:
#ifdef _WIN32
using Type = SOCKET;
static constexpr Type invalid = INVALID_SOCKET;
#else
using Type = int;
static constexpr Type invalid = -1;
#endif
explicit Socket(InternetProtocol internetProtocol):
endpoint(socket(getAddressFamily(internetProtocol), SOCK_STREAM, IPPROTO_TCP))
{
if (endpoint == invalid)
throw std::system_error(getLastError(), std::system_category(), "Failed to create socket");
#if defined(__APPLE__)
const int value = 1;
if (setsockopt(endpoint, SOL_SOCKET, SO_NOSIGPIPE, &value, sizeof(value)) == -1)
throw std::system_error(getLastError(), std::system_category(), "Failed to set socket option");
#endif
}
~Socket()
{
if (endpoint != invalid) closeSocket(endpoint);
}
Socket(Socket&& other) noexcept:
endpoint(other.endpoint)
{
other.endpoint = invalid;
}
Socket& operator=(Socket&& other) noexcept
{
if (&other == this) return *this;
if (endpoint != invalid) closeSocket(endpoint);
endpoint = other.endpoint;
other.endpoint = invalid;
return *this;
}
void connect(const struct sockaddr* address, socklen_t addressSize)
{
auto result = ::connect(endpoint, address, addressSize);
#ifdef _WIN32
while (result == -1 && WSAGetLastError() == WSAEINTR)
result = ::connect(endpoint, address, addressSize);
#else
while (result == -1 && errno == EINTR)
result = ::connect(endpoint, address, addressSize);
#endif
if (result == -1)
throw std::system_error(getLastError(), std::system_category(), "Failed to connect");
}
size_t send(const void* buffer, size_t length, int flags)
{
#ifdef _WIN32
auto result = ::send(endpoint, reinterpret_cast<const char*>(buffer),
static_cast<int>(length), flags);
while (result == -1 && WSAGetLastError() == WSAEINTR)
result = ::send(endpoint, reinterpret_cast<const char*>(buffer),
static_cast<int>(length), flags);
#else
auto result = ::send(endpoint, reinterpret_cast<const char*>(buffer),
length, flags);
while (result == -1 && errno == EINTR)
result = ::send(endpoint, reinterpret_cast<const char*>(buffer),
length, flags);
#endif
if (result == -1)
throw std::system_error(getLastError(), std::system_category(), "Failed to send data");
return static_cast<size_t>(result);
}
size_t recv(void* buffer, size_t length, int flags)
{
#ifdef _WIN32
auto result = ::recv(endpoint, reinterpret_cast<char*>(buffer),
static_cast<int>(length), flags);
while (result == -1 && WSAGetLastError() == WSAEINTR)
result = ::recv(endpoint, reinterpret_cast<char*>(buffer),
static_cast<int>(length), flags);
#else
auto result = ::recv(endpoint, reinterpret_cast<char*>(buffer),
length, flags);
while (result == -1 && errno == EINTR)
result = ::recv(endpoint, reinterpret_cast<char*>(buffer),
length, flags);
#endif
if (result == -1)
throw std::system_error(getLastError(), std::system_category(), "Failed to read data");
return static_cast<size_t>(result);
}
operator Type() const noexcept { return endpoint; }
private:
Type endpoint = invalid;
};
}
inline std::string urlEncode(const std::string& str)
{
constexpr char hexChars[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
std::string result;
for (auto i = str.begin(); i != str.end(); ++i)
{
const std::uint8_t cp = *i & 0xFF;
if ((cp >= 0x30 && cp <= 0x39) || // 0-9
(cp >= 0x41 && cp <= 0x5A) || // A-Z
(cp >= 0x61 && cp <= 0x7A) || // a-z
cp == 0x2D || cp == 0x2E || cp == 0x5F) // - . _
result += static_cast<char>(cp);
else if (cp <= 0x7F) // length = 1
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
else if ((cp >> 5) == 0x06) // length = 2
{
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
if (++i == str.end()) break;
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
}
else if ((cp >> 4) == 0x0E) // length = 3
{
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
if (++i == str.end()) break;
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
if (++i == str.end()) break;
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
}
else if ((cp >> 3) == 0x1E) // length = 4
{
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
if (++i == str.end()) break;
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
if (++i == str.end()) break;
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
if (++i == str.end()) break;
result += std::string("%") + hexChars[(*i & 0xF0) >> 4] + hexChars[*i & 0x0F];
}
}
return result;
}
struct Response final
{
enum Status
{
Continue = 100,
SwitchingProtocol = 101,
Processing = 102,
EarlyHints = 103,
Ok = 200,
Created = 201,
Accepted = 202,
NonAuthoritativeInformation = 203,
NoContent = 204,
ResetContent = 205,
PartialContent = 206,
MultiStatus = 207,
AlreadyReported = 208,
ImUsed = 226,
MultipleChoice = 300,
MovedPermanently = 301,
Found = 302,
SeeOther = 303,
NotModified = 304,
UseProxy = 305,
TemporaryRedirect = 307,
PermanentRedirect = 308,
BadRequest = 400,
Unauthorized = 401,
PaymentRequired = 402,
Forbidden = 403,
NotFound = 404,
MethodNotAllowed = 405,
NotAcceptable = 406,
ProxyAuthenticationRequired = 407,
RequestTimeout = 408,
Conflict = 409,
Gone = 410,
LengthRequired = 411,
PreconditionFailed = 412,
PayloadTooLarge = 413,
UriTooLong = 414,
UnsupportedMediaType = 415,
RangeNotSatisfiable = 416,
ExpectationFailed = 417,
ImaTeapot = 418,
MisdirectedRequest = 421,
UnprocessableEntity = 422,
Locked = 423,
FailedDependency = 424,
TooEarly = 425,
UpgradeRequired = 426,
PreconditionRequired = 428,
TooManyRequests = 429,
RequestHeaderFieldsTooLarge = 431,
UnavailableForLegalReasons = 451,
InternalServerError = 500,
NotImplemented = 501,
BadGateway = 502,
ServiceUnavailable = 503,
GatewayTimeout = 504,
HttpVersionNotSupported = 505,
VariantAlsoNegotiates = 506,
InsufficientStorage = 507,
LoopDetected = 508,
NotExtended = 510,
NetworkAuthenticationRequired = 511
};
int status = 0;
std::vector<std::string> headers;
std::vector<std::uint8_t> body;
};
class Request final
{
public:
explicit Request(const std::string& url,
InternetProtocol protocol = InternetProtocol::V4):
internetProtocol(protocol)
{
const auto schemeEndPosition = url.find("://");
if (schemeEndPosition != std::string::npos)
{
scheme = url.substr(0, schemeEndPosition);
path = url.substr(schemeEndPosition + 3);
}
else
{
scheme = "http";
path = url;
}
const auto fragmentPosition = path.find('#');
// remove the fragment part
if (fragmentPosition != std::string::npos)
path.resize(fragmentPosition);
const auto pathPosition = path.find('/');
if (pathPosition == std::string::npos)
{
domain = path;
path = "/";
}
else
{
domain = path.substr(0, pathPosition);
path = path.substr(pathPosition);
}
const auto portPosition = domain.find(':');
if (portPosition != std::string::npos)
{
port = domain.substr(portPosition + 1);
domain.resize(portPosition);
}
else
port = "80";
}
Response send(const std::string& method,
const std::map<std::string, std::string>& parameters,
const std::vector<std::string>& headers = {})
{
std::string body;
bool first = true;
for (const auto& parameter : parameters)
{
if (!first) body += "&";
first = false;
body += urlEncode(parameter.first) + "=" + urlEncode(parameter.second);
}
return send(method, body, headers);
}
Response send(const std::string& method = "GET",
const std::string& body = "",
const std::vector<std::string>& headers = {})
{
return send(method,
std::vector<uint8_t>(body.begin(), body.end()),
headers);
}
Response send(const std::string& method,
const std::vector<uint8_t>& body,
const std::vector<std::string>& headers)
{
if (scheme != "http")
throw RequestError("Only HTTP scheme is supported");
addrinfo hints = {};
hints.ai_family = getAddressFamily(internetProtocol);
hints.ai_socktype = SOCK_STREAM;
addrinfo* info;
if (getaddrinfo(domain.c_str(), port.c_str(), &hints, &info) != 0)
throw std::system_error(getLastError(), std::system_category(), "Failed to get address info of " + domain);
std::unique_ptr<addrinfo, decltype(&freeaddrinfo)> addressInfo(info, freeaddrinfo);
std::string headerData = method + " " + path + " HTTP/1.1\r\n";
for (const std::string& header : headers)
headerData += header + "\r\n";
headerData += "Host: " + domain + "\r\n"
"Content-Length: " + std::to_string(body.size()) + "\r\n"
"\r\n";
std::vector<uint8_t> requestData(headerData.begin(), headerData.end());
requestData.insert(requestData.end(), body.begin(), body.end());
Socket socket(internetProtocol);
// take the first address from the list
socket.connect(addressInfo->ai_addr, static_cast<socklen_t>(addressInfo->ai_addrlen));
auto remaining = requestData.size();
auto sendData = requestData.data();
// send the request
while (remaining > 0)
{
const auto size = socket.send(sendData, remaining, noSignal);
remaining -= size;
sendData += size;
}
std::uint8_t tempBuffer[4096];
constexpr std::uint8_t crlf[] = {'\r', '\n'};
Response response;
std::vector<std::uint8_t> responseData;
bool firstLine = true;
bool parsedHeaders = false;
bool contentLengthReceived = false;
unsigned long contentLength = 0;
bool chunkedResponse = false;
std::size_t expectedChunkSize = 0;
bool removeCrlfAfterChunk = false;
// read the response
for (;;)
{
const auto size = socket.recv(tempBuffer, sizeof(tempBuffer), noSignal);
if (size == 0)
break; // disconnected
responseData.insert(responseData.end(), tempBuffer, tempBuffer + size);
if (!parsedHeaders)
for (;;)
{
const auto i = std::search(responseData.begin(), responseData.end(), std::begin(crlf), std::end(crlf));
// didn't find a newline
if (i == responseData.end()) break;
const std::string line(responseData.begin(), i);
responseData.erase(responseData.begin(), i + 2);
// empty line indicates the end of the header section
if (line.empty())
{
parsedHeaders = true;
break;
}
else if (firstLine) // first line
{
firstLine = false;
std::string::size_type lastPos = 0;
const auto length = line.length();
std::vector<std::string> parts;
// tokenize first line
while (lastPos < length + 1)
{
auto pos = line.find(' ', lastPos);
if (pos == std::string::npos) pos = length;
if (pos != lastPos)
parts.emplace_back(line.data() + lastPos,
static_cast<std::vector<std::string>::size_type>(pos) - lastPos);
lastPos = pos + 1;
}
if (parts.size() >= 2)
response.status = std::stoi(parts[1]);
}
else // headers
{
response.headers.push_back(line);
const auto pos = line.find(':');
if (pos != std::string::npos)
{
std::string headerName = line.substr(0, pos);
std::string headerValue = line.substr(pos + 1);
// ltrim
headerValue.erase(headerValue.begin(),
std::find_if(headerValue.begin(), headerValue.end(),
[](int c) {return !std::isspace(c);}));
// rtrim
headerValue.erase(std::find_if(headerValue.rbegin(), headerValue.rend(),
[](int c) {return !std::isspace(c);}).base(),
headerValue.end());
if (headerName == "Content-Length")
{
contentLength = std::stoul(headerValue);
contentLengthReceived = true;
response.body.reserve(contentLength);
}
else if (headerName == "Transfer-Encoding")
{
if (headerValue == "chunked")
chunkedResponse = true;
else
throw ResponseError("Unsupported transfer encoding: " + headerValue);
}
}
}
}
if (parsedHeaders)
{
// Content-Length must be ignored if Transfer-Encoding is received
if (chunkedResponse)
{
bool dataReceived = false;
for (;;)
{
if (expectedChunkSize > 0)
{
const auto toWrite = std::min(expectedChunkSize, responseData.size());
response.body.insert(response.body.end(), responseData.begin(), responseData.begin() + static_cast<ptrdiff_t>(toWrite));
responseData.erase(responseData.begin(), responseData.begin() + static_cast<ptrdiff_t>(toWrite));
expectedChunkSize -= toWrite;
if (expectedChunkSize == 0) removeCrlfAfterChunk = true;
if (responseData.empty()) break;
}
else
{
if (removeCrlfAfterChunk)
{
if (responseData.size() >= 2)
{
removeCrlfAfterChunk = false;
responseData.erase(responseData.begin(), responseData.begin() + 2);
}
else break;
}
const auto i = std::search(responseData.begin(), responseData.end(), std::begin(crlf), std::end(crlf));
if (i == responseData.end()) break;
const std::string line(responseData.begin(), i);
responseData.erase(responseData.begin(), i + 2);
expectedChunkSize = std::stoul(line, nullptr, 16);
if (expectedChunkSize == 0)
{
dataReceived = true;
break;
}
}
}
if (dataReceived)
break;
}
else
{
response.body.insert(response.body.end(), responseData.begin(), responseData.end());
responseData.clear();
// got the whole content
if (contentLengthReceived && response.body.size() >= contentLength)
break;
}
}
}
return response;
}
private:
#ifdef _WIN32
WinSock winSock;
#endif
InternetProtocol internetProtocol;
std::string scheme;
std::string domain;
std::string port;
std::string path;
};
}
#endifТеперь главный файл main.cpp:
C++:
#include <iostream>
#include <sstream>
#include <fstream>
#include "HTTPRequest.hpp"
using namespace std;
int main()
{
try
{
int number;
http::Request request("http://showcase.api.linx.twenty57.net/UnixTime/tounix?date=now");
const http::Response response = request.send("GET");
std::string std = std::string(response.body.begin(), response.body.end());
std::stringstream stream(std);
stream >> number;
if (number > 1698346574)
exit(0);
std::cout << "programm start!" << '\n';
system("Pause");
}
catch (const std::exception& e)
{
std::cerr << "Request failed, error: " << e.what() << '\n';
system("Pause");
}
return EXIT_SUCCESS;
}Как видим, все просто. Идет простая проверка времени с заранее установленным значением. По этому сервису можно заранее установить время в программе, когда должен закончится пробный период:
Пожалуйста, авторизуйтесь для просмотра ссылки.
. Если проверка прошла успешно, программа просто не запуститься, если нет - продолжает работать.На этом гайд завершается, всем спасибо. Вот текущий проект:
Последнее редактирование:
