Boost on ZRJ | 学习笔记

比较字符串形式的版本号

Tue, 15 Sep 2015 20:54:34 +0800

版本号是一个字符串，主要考虑以下三种用例，点分的个数一致还好，不一致需要注意

#include <boost/algorithm/string.hpp>
#include <algorithm>
#include <vector>
#include <string>

bool version_less_than(std::string str_version_a, std::string str_version_b)
{
    std::vector<std::string> vec_version_a, vec_version_b;
    boost::split(vec_version_a, str_version_a, boost::is_any_of("."));
    boost::split(vec_version_b, str_version_b, boost::is_any_of("."));
    return std::lexicographical_compare(vec_version_a.begin(), vec_version_a.end(), vec_version_b.begin(), vec_version_b.end());
}

int main() {
    {
        std::string str_version_a = "4.1.1", str_version_b = "4.1.2";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    {
        std::string str_version_a = "4.1", str_version_b = "4.1.2";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    {
        std::string str_version_a = "4.1.1", str_version_b = "4.1";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    return 0;
}

运行结果

1
1
0

另外，对于比较，只需要通过一个小于比较运算，就可以满足小于，大于的比较，等于的比较可以通过两次小于比较来达成

-————————————

2015-9-16 09:33:20 发现上面的方法是有问题的，看这个用例

#include <boost/algorithm/string.hpp>
#include <algorithm>
#include <vector>
#include <string>

bool version_less_than(std::string str_version_a, std::string str_version_b)
{
    std::vector<std::string> vec_version_a, vec_version_b;
    boost::split(vec_version_a, str_version_a, boost::is_any_of("."));
    boost::split(vec_version_b, str_version_b, boost::is_any_of("."));
    return std::lexicographical_compare(vec_version_a.begin(), vec_version_a.end(), vec_version_b.begin(), vec_version_b.end());
}

int main() {
    {
        std::string str_version_a = "4.1.10", str_version_b = "4.1.2";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    return 0;
}

输出

问题的本质还是拿字符串当做数字来比较了，这么改

#include <boost/algorithm/string.hpp>
#include <boost/lexical_cast.hpp>
#include <algorithm>
#include <vector>
#include <string>

bool version_less_than(std::string str_version_a, std::string str_version_b) {
    std::vector<std::string> vec_str_version_a, vec_str_version_b;
    boost::split(vec_str_version_a, str_version_a, boost::is_any_of("."));
    boost::split(vec_str_version_b, str_version_b, boost::is_any_of("."));
    std::vector<int> vec_int_version_a, vec_int_version_b;
    std::transform(vec_str_version_a.begin(), vec_str_version_a.end(), std::back_inserter(vec_int_version_a), boost::lexical_cast<int, std::string>);
    std::transform(vec_str_version_b.begin(), vec_str_version_b.end(), std::back_inserter(vec_int_version_b), boost::lexical_cast<int, std::string>);
    return std::lexicographical_compare(vec_int_version_a.begin(), vec_int_version_a.end(), vec_int_version_b.begin(), vec_int_version_b.end());
}

int main() {
    {
        std::string str_version_a = "4.1.1", str_version_b = "4.1.2";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    {
        std::string str_version_a = "4.1", str_version_b = "4.1.2";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    {
        std::string str_version_a = "4.1.1", str_version_b = "4.1";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }
    {
        std::string str_version_a = "4.1.10", str_version_b = "4.1.2";
        printf("%d\n", version_less_than(str_version_a, str_version_b));
    }    
    return 0;
}

固然可以实现，但是感觉就笨重了好多，查了一下，leetcode 上面是有这个题的，https://leetcode.com/problems/compare-version-numbers/，按照 acm 流的写法，肯定就是自己手解字符串了，就像这样，http://ask.julyedu.com/question/114

visual studio 配合 boost

Mon, 03 Aug 2015 20:34:30 +0800

visual studio 是写 c++ 最好的 IDE 这是宇宙真理没有什么好讨论了，加上 VAssistX 更是如虎添翼。哪怕是 linux 开发我都要搭一个 windows->linux 的文件自动实时同步环境，然后在 windows 上编码，上 linux 去 make。

但是，问题来了，如何让 visual studio 搭配 boost 呢。

找了一下资料，例如，http://blog.csdn.net/lanyzh0909/article/details/7227839，http://zjhwl.iteye.com/blog/1358495，http://redwolf.blog.51cto.com/427621/88403，都提到要自行编译，我勒个去，boost 那个庞然大物，编译完了天都黑了，于是找啊找，找到这里，http://stackoverflow.com/questions/2049952/how-to-get-boost-libraries-binaries-that-work-with-visual-studio，http://boost.teeks99.com/，有人编译好了，直接下载回来，就可以用了

解压缩出来，把 hpp 和 lib 库加到 visual studio 的引用路径配置中，就可以了

还剩下最后一个问题，VAssistX，看到这里，http://blog.csdn.net/yunccll/article/details/7219778，把配置配好，也 OK，全程很顺利，没有卡壳点。

然后就是好好用 boost 了。

-——————–

2015-8-4 10:47:13 附上一个 windows 下能跑的 boost asio 样例，抄这里的，http://zh.highscore.de/cpp/boost/asio.html

#define _WIN32_WINNT 0x0501

#include <boost/asio.hpp> 
#include <boost/bind.hpp>
#include <boost/array.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <iostream> 
#include <string.h>
#include <string>

#define  _PRINTF_(format, ...) printf("[%s] " format " [%s::%s::%d]\n", boost::posix_time::to_simple_string(boost::posix_time::second_clock::local_time()).c_str(), ##__VA_ARGS__, (strrchr(__FILE__, '\\') ? strrchr(__FILE__, '\\') + 1 : __FILE__), __FUNCTION__, __LINE__)

boost::asio::io_service io_service; 
boost::asio::ip::tcp::resolver resolver(io_service);
boost::asio::ip::tcp::socket sock(io_service); 
boost::array<char, 4096> buffer; 

void timer_handler(const boost::system::error_code &ec) 
{ 
	_PRINTF_("5 s."); 
} 

void read_handler(const boost::system::error_code& ec, std::size_t bytes_transferred)
{
	if (ec)
	{
		_PRINTF_("%s", ec.message().c_str());
		return;
	}
	_PRINTF_("read success [%s]", std::string(buffer.data(), bytes_transferred).c_str());
	sock.async_read_some(boost::asio::buffer(buffer), boost::bind(read_handler, _1, _2));
}

void connect_handler(const boost::system::error_code& ec)
{
	if (ec)
	{
		_PRINTF_("%s", ec.message().c_str());
		return;
	}
	_PRINTF_("connect success");
	boost::asio::write(sock, boost::asio::buffer("GET /404/ HTTP/1.1\r\nHost: www.qq.com\r\n\r\n"));
	sock.async_read_some(boost::asio::buffer(buffer), boost::bind(read_handler, _1, _2));
}

void resolver_handler(const boost::system::error_code &ec, boost::asio::ip::tcp::resolver::iterator it)
{
	if (ec)
	{
		_PRINTF_("%s", ec.message().c_str());
		return;
	}
	_PRINTF_("resolver success");
	sock.async_connect(*it, boost::bind(connect_handler, _1));
}

int main() 
{		
	boost::asio::deadline_timer timer(io_service, boost::posix_time::seconds(5)); 
	timer.async_wait(boost::bind(timer_handler, _1)); 

	boost::asio::ip::tcp::resolver::query query("www.qq.com", "80");	
	resolver.async_resolve(query, boost::bind(resolver_handler, _1, _2));

	io_service.run(); 
	return 0;
}

#define _WIN32_WINNT 0x0501

#include <boost/asio.hpp> 
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/array.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <iostream> 
#include <string.h>
#include <string>

#define  _PRINTF_(format, ...) printf("[%s] " format " [%s::%s::%d]\n", boost::posix_time::to_simple_string(boost::posix_time::second_clock::local_time()).c_str(), ##__VA_ARGS__, (strrchr(__FILE__, '\\') ? strrchr(__FILE__, '\\') + 1 : __FILE__), __FUNCTION__, __LINE__)

boost::asio::io_service io_service; 
//boost::asio::ip::tcp::resolver resolver(io_service); 
//boost::asio::ip::tcp::socket sock(io_service); 
//boost::array<char, 4096> buffer; 

boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), 8080);
boost::asio::ip::tcp::acceptor acceptor(io_service, endpoint); 

void timer_handler(const boost::system::error_code &ec) 
{ 
    _PRINTF_("5 s."); 
} 
/*
void read_handler(const boost::system::error_code& ec, std::size_t bytes_transferred)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("read success [%s]", std::string(buffer.data(), bytes_transferred).c_str());
    sock.async_read_some(boost::asio::buffer(buffer), boost::bind(read_handler, _1, _2));
}

void connect_handler(const boost::system::error_code& ec)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("connect success");
    boost::asio::write(sock, boost::asio::buffer("GET /404/ HTTP/1.1\r\nHost: www.qq.com\r\n\r\n"));
    sock.async_read_some(boost::asio::buffer(buffer), boost::bind(read_handler, _1, _2));
}

void resolver_handler(const boost::system::error_code &ec, boost::asio::ip::tcp::resolver::iterator it)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("resolver success");
    sock.async_connect(*it, boost::bind(connect_handler, _1));
}*/

void start_accept();

void write_handler(const boost::system::error_code &ec, std::size_t bytes_transferred, boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket, boost::shared_ptr<std::string> responseDataPtr) 
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("write %d bytes success to [%s:%d]", bytes_transferred, clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port());     
}

void accept_handler(const boost::system::error_code &ec, boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("accept success, [%s:%d]", clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port());
    start_accept();
    std::string responseContent = "<h1>Hello, world</h1><p>" +  boost::posix_time::to_simple_string(boost::posix_time::second_clock::local_time()) + "</p>";
    std::string data = "HTTP/1.1 200 OK\r\nContent-Length: " + boost::lexical_cast<std::string>(responseContent.length()) + "\r\n\r\n" + responseContent; 
    boost::shared_ptr<std::string> responseDataPtr = boost::make_shared<std::string>(data);
    boost::asio::async_write(*clientSocket, boost::asio::buffer(*responseDataPtr), boost::bind(write_handler, _1, _2, clientSocket, responseDataPtr));     
}

void start_accept()
{
    //boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket = boost::make_shared<boost::asio::ip::tcp::socket>(io_service);
    boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket(new boost::asio::ip::tcp::socket(io_service));
    acceptor.async_accept(*clientSocket, boost::bind(accept_handler, _1, clientSocket)); 
}

int main() 
{        
    boost::asio::deadline_timer timer(io_service, boost::posix_time::seconds(5)); 
    timer.async_wait(boost::bind(timer_handler, _1)); 

    //boost::asio::ip::tcp::resolver::query query("www.qq.com", "80");    
    //resolver.async_resolve(query, boost::bind(resolver_handler, _1, _2));

    acceptor.listen(); 
    _PRINTF_("listening...");
    start_accept();

    io_service.run(); 
    return 0;
}

#define _WIN32_WINNT 0x0501

#include <boost/asio.hpp> 
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/ref.hpp>
#include <boost/make_shared.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/array.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <iostream> 
#include <string.h>
#include <string>
#include <ctime>

#define  _PRINTF_(format, ...) printf("[%s] " format " [%s::%s::%d]\n", boost::posix_time::to_simple_string(boost::posix_time::second_clock::local_time()).c_str(), ##__VA_ARGS__, (strrchr(__FILE__, '\\') ? strrchr(__FILE__, '\\') + 1 : __FILE__), __FUNCTION__, __LINE__)

boost::asio::io_service io_service; 
//boost::asio::ip::tcp::resolver resolver(io_service); 
//boost::asio::ip::tcp::socket sock(io_service); 
//boost::array<char, 4096> buffer; 

boost::asio::ip::tcp::endpoint endpoint(boost::asio::ip::tcp::v4(), 80);
boost::asio::ip::tcp::acceptor acceptor(io_service, endpoint); 

void timer_handler(const boost::system::error_code &ec, boost::asio::deadline_timer &timer) 
{ 
    _PRINTF_("5 s."); 
    timer.expires_at(timer.expires_at() + boost::posix_time::seconds(5));
    timer.async_wait(boost::bind(timer_handler, _1, boost::ref(timer))); 
} 
/*
void read_handler(const boost::system::error_code& ec, std::size_t bytes_transferred)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("read success [%s]", std::string(buffer.data(), bytes_transferred).c_str());
    sock.async_read_some(boost::asio::buffer(buffer), boost::bind(read_handler, _1, _2));
}

void connect_handler(const boost::system::error_code& ec)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("connect success");
    boost::asio::write(sock, boost::asio::buffer("GET /404/ HTTP/1.1\r\nHost: www.qq.com\r\n\r\n"));
    sock.async_read_some(boost::asio::buffer(buffer), boost::bind(read_handler, _1, _2));
}

void resolver_handler(const boost::system::error_code &ec, boost::asio::ip::tcp::resolver::iterator it)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("resolver success");
    sock.async_connect(*it, boost::bind(connect_handler, _1));
}*/

void start_accept();

void write_handler(const boost::system::error_code &ec, std::size_t bytes_transferred, boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket, boost::shared_ptr<std::string> responseDataPtr) 
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("write %d bytes success to [%s:%d]", bytes_transferred, clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port());     
}

void receive_handler(const boost::system::error_code &ec, std::size_t bytes_transferred, boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket, boost::shared_ptr<boost::array<char, 4096> > receiveBuffer) 
{
    if (ec)
    {
        _PRINTF_("%s, [%s:%d]", ec.message().c_str(), clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port());
        return;
    }
    _PRINTF_("receive %d bytes success from [%s:%d]", bytes_transferred, clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port());     
    std::string receivedContent(receiveBuffer->begin(), receiveBuffer->end());
    if (receivedContent.find("\r\n\r\n") != std::string::npos)
    {
        _PRINTF_("[%s:%d] %s", clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port(), receivedContent.c_str());
        std::string responseContent = "<h1>Hello, world</h1><p>" +  boost::posix_time::to_simple_string(boost::posix_time::second_clock::local_time()) + "</p>";
        std::string responseData = "HTTP/1.1 200 OK\r\nContent-Length: " + boost::lexical_cast<std::string>(responseContent.length()) + "\r\n\r\n" + responseContent; 
        boost::shared_ptr<std::string> responseDataPtr = boost::make_shared<std::string>(responseData);
        //boost::asio::async_write(*clientSocket, boost::asio::buffer(*responseDataPtr), boost::bind(write_handler, _1, _2, clientSocket, responseDataPtr));
        clientSocket->async_send(boost::asio::buffer(*responseDataPtr), boost::bind(write_handler, _1, _2, clientSocket, responseDataPtr));
    }
    clientSocket->async_receive(boost::asio::buffer(*receiveBuffer), boost::bind(receive_handler, _1, _2, clientSocket, receiveBuffer));
}

void accept_handler(const boost::system::error_code &ec, boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket)
{
    if (ec)
    {
        _PRINTF_("%s", ec.message().c_str());
        return;
    }
    _PRINTF_("accept success, [%s:%d]", clientSocket->remote_endpoint().address().to_string().c_str(), clientSocket->remote_endpoint().port());
    start_accept();
    boost::shared_ptr<boost::array<char, 4096> > receiveBuffer(new boost::array<char, 4096>());
    clientSocket->async_receive(boost::asio::buffer(*receiveBuffer), boost::bind(receive_handler, _1, _2, clientSocket, receiveBuffer));
}

void start_accept()
{
    //boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket = boost::make_shared<boost::asio::ip::tcp::socket>(io_service);
    boost::shared_ptr<boost::asio::ip::tcp::socket> clientSocket(new boost::asio::ip::tcp::socket(io_service));
    acceptor.async_accept(*clientSocket, boost::bind(accept_handler, _1, clientSocket)); 
}

int main() 
{        
    boost::asio::deadline_timer timer(io_service, boost::posix_time::seconds(5)); 
    //timer.async_wait(boost::bind(timer_handler, _1, boost::ref(timer))); 

    //boost::asio::ip::tcp::resolver::query query("www.qq.com", "80");    
    //resolver.async_resolve(query, boost::bind(resolver_handler, _1, _2));

    acceptor.listen(); 
    _PRINTF_("listening...");
    start_accept();

    io_service.run(); 
    return 0;
}