How do I open a URL from C++?

Question

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;
}

Libraries like Qt provide a platform independent way to do this. There is nothing in the c++ language itself to provide that. — drescherjm, Jun 27 '13 at 16:04
Curl is good as other people have pointed out. But there probably is something like this in the environment that you are using. Using that would be a better way since you don't have to add an extra library and it would be more in the style of the rest of your application. — mike jones, Jun 27 '13 at 16:11
Do you want to launch the default browser from your C++ code and open the url or do you want to download the webpage to your c++ application for your own processing of the html? — drescherjm, Jun 27 '13 at 16:16

score 58 · Answer 1 · edited Jan 28 '20 at 17:55

58

Your question may mean two different things:

1.) Open a web page with a browser.

#include <windows.h>
#include <shellapi.h>
...
ShellExecute(0, 0, L"http://www.google.com", 0, 0 , SW_SHOW );

This should work, it opens the file with the associated program. Should open the browser, which is usually the default web browser.

2.) Get the code of a webpage and you will render it yourself or do some other thing. For this I recommend 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.

edited Jan 28 '20 at 17:55

Ramzis

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answered Jun 27 '13 at 16:13

ST3

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it's for Windows only, right? I mean ShellExecute. Thanks anyway – rodrigoalvesvieira Jun 27 '13 at 16:18
2

This is a windows only solution for launching the default browser to open a URL. The OP did mention platform independent. Qt would provide that although it would be quite heavy for just this task.. – drescherjm Jun 27 '13 at 16:19
Just to make this question a little more interesting: What if I want to run an ordinary terminal program from my C/C++ code. Is there a way? For example, run cd – rodrigoalvesvieira Jun 27 '13 at 16:20
You can use the system() function to launch a program. And I mean executable program not a document. – drescherjm Jun 27 '13 at 16:24
2

Argument 3 should not be wide-char string: remove the `L` or use `ShellExecuteW`. – Salvador Jan 12 '17 at 16:42
1

@Salvador `ShellExecute` is a macro which expands to `ShellExecuteA` or `ShellExecuteW`. I didn't see anyone to use compilation settings to make it expand into `A` version in nowadays. – ST3 Jan 13 '17 at 08:34

rectummelancolique · Accepted Answer · 2013-06-27T16:23:18.940

30

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.

edited Jun 27 '13 at 16:23

answered Jun 27 '13 at 16:06

rectummelancolique

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4

Your update is exactly what I wanted. See application at https://gist.github.com/rodrigoalvesvieira/662e400f34dd9de38176 – rodrigoalvesvieira Jul 15 '13 at 03:00

score 9 · Answer 3 · answered Jun 27 '13 at 18:33

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;
}

This is actually what the title of the thread currently says however I believe from the comments that the question is actually "How do I open a url in the default browser from c++ code using a platform independent method?" — drescherjm, Jun 27 '13 at 18:35

Gonçalo Peres · Answer 4 · 2020-02-14T12:31:45.597

I was having the exact same problem in Windows.

I noticed that in OP's gist, he uses string("open ") in line 21, however, by using it one comes across this error:

'open' is not recognized as an internal or external command

After researching, I have found that open is MacOS the default command to open things. It is different on Windows or Linux.

Linux: xdg-open <URL>

Windows: start <URL>

For those of you that are using Windows, as I am, you can use the following:

std::string op = std::string("start ").append(url);
system(op.c_str());

score 4 · Answer 5 · edited Dec 23 '14 at 12:59

4

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.

edited Dec 23 '14 at 12:59

fhntv24

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answered Jun 02 '14 at 17:33

ahogen

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Thank you for catching the quotation mark error. Apparently something was removed when I copied my code over. – ahogen May 19 '15 at 07:18

recolic · Answer 6 · 2018-11-07T13:54:20.483

4

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

edited Nov 07 '18 at 13:54

answered Jan 07 '18 at 05:12

recolic

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@SebastianMach I attached a wrong link. It should be `man 1 open`. Fixed it just now. – recolic Nov 07 '18 at 13:55
This will create a remote execution vulnerability if `url` is user defined – rubenwardy Jun 11 '19 at 16:02
@rubenwardy That's right. And the vulnerability can be fixed by using `execv` or checking url before forging the cmd. – recolic Jun 11 '19 at 16:08
How would you use execv if you don't know the program name? Or would you just use open as the program name? – rubenwardy Jun 11 '19 at 16:10
@rubenwardy You may use `/usr/bin/xdg-open` or `/usr/bin/cygstart`. – recolic Oct 28 '20 at 07:50

score 3 · Answer 7 · answered Jan 09 '20 at 09:01

For linux environments, you can use xdg-open. It is installed by default on most distributions. The benefit over the accepted answer is that it opens the user's preferred browser.

$ xdg-open https://google.com
$ xdg-open steam://run/10

Of course you can wrap this in a system() call.

score 2 · Answer 8 · answered Jun 27 '13 at 16:07

2

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.

answered Jun 27 '13 at 16:07

1

@rodrigoalves Curl is available on just about any OS including many flavors of both Windows and Linux. It's well-worth the time to learn it. It has many, many great features. – Jun 27 '13 at 16:15
Yes. I used frequently from the terminal, mostly to test API outputs and such. Never from within a C++ program, tho. – rodrigoalvesvieira Jun 27 '13 at 16:19

score 0 · Answer 9 · answered Aug 23 '23 at 20:24

Here is a cross platform version to open URL

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__)
#define SystemOpenURL(url) system("start " url);
#elif __APPLE__
#define SystemOpenURL(url) system("open " url);
#elif __linux__
#define SystemOpenURL(url) system("xdg-open" url);
#else
#error "Unknown compiler"
#endif

score -4 · Answer 10 · edited Jan 22 '15 at 12:27

-4

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

edited Jan 22 '15 at 12:27

rene

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answered Jan 22 '15 at 11:23

invadev

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How do I open a URL from C++?

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