Open URL from C++ code

问题:

how can I open a URL from my C++ program?

In ruby you can do

%x(open https://google.com)

What's the equivalent in C++? I wonder if there's a platform-independent solution. But if there isn't, I'd like the Unix/Mac better :)

Here's my code:

#include <stdio.h>
#include <string.h>
#include <fstream>

int main (int argc, char *argv[])
{
    char url[1000] = "https://www.google.com";

    std::fstream fs;
    fs.open(url);
    fs.close();

    return 0;
}

回答1:

Use libcurl, here is a simple example.

EDIT: If this is about starting a web browser from C++, you can invoke a shell command with system on a POSIX system:

system("<mybrowser> http://google.com");

By replacing <mybrowser> with the browser you want to launch.

回答2:

Your question may mean two different things. 1) Open web page with browser.

ShellExecute(0, 0, L"http://www.google.com", 0, 0 , SW_SHOW );

This should work, it opens file with associated program. Should open browser, usually it is default. 2) Get code of webpage and you will render it yourself or do some other thing. For this I would like to read this or/and this

I hope it's at least a little helpful.

EDIT: Did not notice, what you are asking for UNIX, this only work on Windows.

回答3:

Here's an example in windows code using winsock.

#include <winsock2.h>
#include <windows.h>
#include <iostream>
#include <string>
#include <locale>
#pragma comment(lib,"ws2_32.lib")
using namespace std;

string website_HTML;
locale local;


void get_Website(char *url );

int main ()
{
    //open website
    get_Website("www.google.com" );

    //format website HTML
    for (size_t i=0; i<website_HTML.length(); ++i) 
        website_HTML[i]= tolower(website_HTML[i],local);

    //display HTML
    cout <<website_HTML;

    cout<<"\n\n";



    return 0;
}



//***************************
void get_Website(char *url )
{
    WSADATA wsaData;
    SOCKET Socket;
    SOCKADDR_IN SockAddr;


    int lineCount=0;
    int rowCount=0;

    struct hostent *host;
    char *get_http= new char[256];

        memset(get_http,' ', sizeof(get_http) );
        strcpy(get_http,"GET / HTTP/1.1\r\nHost: ");
        strcat(get_http,url);
        strcat(get_http,"\r\nConnection: close\r\n\r\n");

        if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0) 
        {
            cout << "WSAStartup failed.\n";
            system("pause");
            //return 1;
        }

        Socket=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
        host = gethostbyname(url);

        SockAddr.sin_port=htons(80);
        SockAddr.sin_family=AF_INET;
        SockAddr.sin_addr.s_addr = *((unsigned long*)host->h_addr);

        cout << "Connecting to "<< url<<" ...\n";

        if(connect(Socket,(SOCKADDR*)(&SockAddr),sizeof(SockAddr)) != 0)
        {
            cout << "Could not connect";
            system("pause");
            //return 1;
        }

        cout << "Connected.\n";     
        send(Socket,get_http, strlen(get_http),0 );

        char buffer[10000];

        int nDataLength;
            while ((nDataLength = recv(Socket,buffer,10000,0)) > 0)
            {       
                int i = 0;

                while (buffer[i] >= 32 || buffer[i] == '\n' || buffer[i] == '\r') 
                {                    
                    website_HTML+=buffer[i];                     
                    i += 1;
                }               
            }
        closesocket(Socket);
        WSACleanup();

            delete[] get_http;
}

回答4:

C isn't as high-level as the scripting language you mention. But if you want to stay away from socket-based programming, try Curl. Curl is a great C library and has many features. I have used it for years and always recommend it. It also includes some stand alone programs for testing or shell use.

回答5:

I've had MUCH better luck using ShellExecuteA(). I've heard that there are a lot of security risks when you use "system()". This is what I came up with for my own code.

void SearchWeb( string word )
{    
    string base_URL = "http://www.bing.com/search?q=";
    string search_URL = "dummy";
    search_URL = base_URL + word;

    cout << "Searching for: \"" << word << "\"\n";

    ShellExecuteA(NULL, "open", search_URL.c_str(), NULL, NULL, SW_SHOWNORMAL);
}

p.s. Its using WinAPI if i'm correct. So its not multiplatform solution.

回答6:

There're already answers for windows. In linux, I noticed open https://www.google.com always launch browser from shell, so you can try:

system("open https://your.domain/uri");

that's say

system(("open "s + url).c_str()); // c++

https://linux.die.net/man/1/open

回答7:

Create a function and copy the code using winsock which is mentioned already by Software_Developer.

For Instance:

#ifdef _WIN32

// this is required only for windows

if (WSAStartup(MAKEWORD(2,2), &wsaData) != 0)
{

  //...

}

#endif

winsock code here

#ifdef _WIN32

WSACleanup();

#endif