使用boost asio获取网页
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【中文标题】使用boost asio获取网页【英文标题】：Using boost asio to get web page 【发布时间】：2017-12-08 02:33:33 【问题描述】：我正在尝试构建一个程序，该程序将接收股票行情、运行谷歌搜索并输出数据（当前价格、最高价、最低价、百分比变化等）。我正在尝试使用 boost asio，但它没有从服务器返回任何数据。
#include "stdafx.h"
#include <iostream>
#include <istream>
#include <ostream>
#include <string>
#include <boost/asio.hpp>
std::string getStockPage(std::string ticker)
boost::asio::ip::tcp::iostream stream;
stream.connect("www.google.com", "http");
std::cout << "connected\n";
stream << "GET /search?q=" << ticker << " HTTP/1.1\r\n";
stream << "Host: www.google.com\r\n";
stream << "Cache-Control: no-cache\r\n";
//stream << "Content-Type: application/x-www-form-urlencoded\r\n\r\n";
stream << "Connection: close\r\n\r\n";
std::cout << "sent\n";
std::ostringstream os;
//os << stream.rdbuf();
char buffer[100];
os << stream.readsome(buffer, 100);
return std::string(buffer, 100);
int main()
std::cout << getStockPage("$tsla");
std::cout << "done\n";
std::string temp;
std::getline(std::cin, temp);
return 0;
我尝试只读取前 100 个字符，看看它是否在输出响应时出现问题，但它只输出空字符。我希望它输出整个谷歌页面“www.google.com/search?q=$tsla”
任何帮助将不胜感激！
【问题讨论】：
boost.org/doc/libs/1_65_1/doc/html/boost_asio/example/cpp03/… Sending http GET request using boost::asio, similar to cURL的可能重复 【参考方案1】：std::istream::readsome 被允许总是返回 0 个字节。然后，看起来好像您收到了 NUL 字节，因为您收到了
return std::string(buffer, 100);
而不是
return std::string(buffer, stream.gcount());
真的，就用其他方法
std::ostringstream os;
os << stream.rdbuf();
return os.str();
这在测试时对我有用。请注意，您可以添加冲洗：
stream << "Connection: close\r\n\r\n" << std::flush;
生成的程序
#include <boost/asio.hpp>
#include <iostream>
#include <string>
std::string getStockPage(std::string const& ticker)
boost::asio::ip::tcp::iostream stream;
stream.connect("www.google.com", "http");
stream << "GET /search?q=" << ticker << " HTTP/1.1\r\n";
stream << "Host: www.google.com\r\n";
stream << "Cache-Control: no-cache\r\n";
// stream << "Content-Type: application/x-www-form-urlencoded\r\n\r\n";
stream << "Connection: close\r\n\r\n" << std::flush;
std::ostringstream os;
os << stream.rdbuf();
return os.str();
int main()
std::cout << getStockPage("$tsla");
正在打印
HTTP/1.1 302 Found
Location: http://www.google.nl/search?q=%24tsla&gws_rd=cr&dcr=0&ei=3EMqWrKxCILUwAKv9LqICg
Cache-Control: private
Content-Type: text/html; charset=UTF-8
P3P: CP="This is not a P3P policy! See g.co/p3phelp for more info."
Date: Fri, 08 Dec 2017 07:48:44 GMT
Server: gws
Content-Length: 288
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN
Set-Cookie: NID=118=MsVZZpoZFEz4mQDqDuuWFRViB8v8yEQju7FPdOw8Rr7ViQ1cJtF6ZeN9u-dSRhGMT4x8F8yDilk9FqsoTkO8IsoQX-YvHXRcCoHcOLk0p4VOTn8AZoldKeh84Ryl0bM0; expires=Sat, 09-Jun-2018 07:48:44 GMT; path=/; domain=.google.com; HttpOnly
Connection: close
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>302 Moved</TITLE></HEAD><BODY>
<H1>302 Moved</H1>
The document has moved
<A HREF="http://www.google.nl/search?q=%24tsla&gws_rd=cr&dcr=0&ei=3EMqWrKxCILUwAKv9LqICg">here</A>.
</BODY></HTML>
【讨论】：
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