jadekler / curlcpp

An object oriented C++ wrapper for CURL

curlcpp

An object-oriented C++ wrapper for cURL tool

If you want to know a bit more about cURL, you should go on the official website and read about the three interfaces that curl implements: http://curl.haxx.se/

Please note: this requires C++11. For Mac users, you will probably need to update your compiler, since xCode provides a dated version.

Compile and link

Standalone

cd build
cmake ..
make # -j2

Then add <curlcpp root>/build/src/ to your library path and <curlcpp root>/include/ to your include path.

When linking, link against curlcpp (e.g.: g++ -std=c++11 example.cpp -o example -lcurlcpp -lcurl). Or if you want run from terminal,

g++ -std=c++11 example.cpp -L/home/arun/path/to/build/src/ -I/home/arun/path/to/include/ -lcurlcpp -lcurl

Submodule

When using a git submodule and CMake-buildsystem, add the following lines to your CMakeLists.txt:

ADD_SUBDIRECTORY(ext/curlcpp) # Change `ext/curlcpp` to a directory according to your setup
INCLUDE_DIRECTORIES(${CURLCPP_SOURCE_DIR}/include)

Simple usage example

Here's an example of a simple HTTP request to get google web page, using the curl_easy interface:

#include "curl_easy.h"

using curl::curl_easy;

int main(int argc, const char **argv) {
    curl_easy easy;
    easy.add(curl_pair<CURLoption,string>(CURLOPT_URL,"http://www.google.it") );
    easy.add(curl_pair<CURLoption,long>(CURLOPT_FOLLOWLOCATION,1L));
    try {
        easy.perform();
    } catch (curl_easy_exception error) {
        // If you want to get the entire error stack we can do:
        vector<pair<string,string>> errors = error.what();
        // Otherwise we could print the stack like this:
        error.print_traceback();
        // Note that the printing the stack will erase it
    }
    return 0;
}

Here's instead, the creation of an HTTPS POST login form:

#include "curl_easy.h"
#include "curl_form.h"

using curl::curl_form;
using curl::curl_easy;

int main(int argc, const char * argv[]) {
    curl_form form;
    curl_easy easy;
    
    // Forms creation
    curl_pair<CURLformoption,string> name_form(CURLFORM_COPYNAME,"user");
    curl_pair<CURLformoption,string> name_cont(CURLFORM_COPYCONTENTS,"you username here");
    curl_pair<CURLformoption,string> pass_form(CURLFORM_COPYNAME,"passw");
    curl_pair<CURLformoption,string> pass_cont(CURLFORM_COPYCONTENTS,"your password here");
    
    try {
    	// Form adding
        form.add(name_form,name_cont);
        form.add(pass_form,pass_cont);
        
        // Add some options to our request
        easy.add(curl_pair<CURLoption,string>(CURLOPT_URL,"your url here"));
        easy.add(curl_pair<CURLoption,bool>(CURLOPT_SSL_VERIFYPEER,false));
        easy.add(curl_pair<CURLoption,curl_form>(CURLOPT_HTTPPOST,form));
        easy.perform();
    } catch (curl_easy_exception error) {
    	// Print errors, if any
        error.print_traceback();
    }
    return 0;
}

And if we would like to put the returned content in a file? Nothing easier than:

#include <iostream>
#include "curl_easy.h"
#include <fstream>

using std::cout;
using std::endl;
using std::ofstream;
using curl::curl_easy;

int main(int argc, const char * argv[]) {
    // Create a file
    ofstream myfile;
    myfile.open ("/Users/Giuseppe/Desktop/test.txt");
    // Create a writer to handle the stream
    
    curl_writer writer(myfile);
    // Pass it to the easy constructor and watch the content returned in that file!
    curl_easy easy(writer);
    
    // Add some option to the easy handle
    easy.add(curl_pair<CURLoption,string>(CURLOPT_URL,"http://www.google.it") );
    easy.add(curl_pair<CURLoption,long>(CURLOPT_FOLLOWLOCATION,1L));
    try {
        easy.perform();
    } catch (curl_easy_exception error) {
        // If you want to get the entire error stack we can do:
        vector<pair<string,string>> errors = error.what();
        // Otherwise we could print the stack like this:
        error.print_traceback();
    }
    myfile.close();
    return 0;
}

I have implemented a sender and a receiver to make it easy to use send/receive without handling buffers. For example, a very simple send/receiver would be:

#include "curl_easy.h"
#include "curl_form.h"
#include "curl_pair.h"
#include "curl_receiver.h"
#include "curl_sender.h"

using curl::curl_form;
using curl::curl_easy;
using curl::curl_sender;
using curl::curl_receiver;

int main(int argc, const char * argv[]) {
    // Simple request
    string request = "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n";
    
    // Creation of easy object.
    curl_easy easy;
    try {
        easy.add(curl_pair<CURLoption,string>(CURLOPT_URL,"http://example.com"));
        // Just connect
        easy.add(curl_pair<CURLoption,bool>(CURLOPT_CONNECT_ONLY,true));
        easy.perform();
    } catch (curl_easy_exception error) {
        // If you want to get the entire error stack we can do:
        vector<pair<string,string>> errors = error.what();
        // Print errors if any
        error.print_traceback();
    }
    
    // Creation of a sender. You should wait here using select to check if socket is ready to send.
    curl_sender<string> sender(easy);
    sender.send(request);
    // Prints che sent bytes number.
    cout<<"Sent bytes: "<<sender.get_sent_bytes()<<endl;
    
    for(;;) {
        // You should wait here to check if socket is ready to receive
        try {
            // Create a receiver
            curl_receiver<char,1024> receiver;
            // Receive the content on the easy handler
            receiver.receive(easy);
            // Prints the received bytes number.
            cout<<"Receiver bytes: "<<receiver.get_received_bytes()<<endl;
        } catch (curl_easy_exception error) {
            // If any errors occurs, exit from the loop
            break;
        }
    }
    return 0;
}