curlev

A C++ library providing a flexible and easy-to-use interface for making Internet requests. It combines the power of libcurl for transfer operations with libuv for asynchronous I/O, offering both synchronous and asynchronous request handling with minimal overhead.

Key features:

• Event driven (uses 4 times less CPU and 2 times less RAM than the best libraries)
• Synchronous and asynchronous requests with callback support
• Supports HTTP and SMTP
• Handles query parameters, form data, MIME handling, and raw bodies
• REST functions using common JSON parsers
• Custom headers and authentication
• Automatic retry on error
• Method chaining

Example of a synchronous request:

#include <curlev/http.hpp>
#include <iostream>

using namespace curlev;

int main( int argc, char ** argv )
{
  ASync async;
  async.start();
  //
  auto http = HTTP::create( async );
  auto code = http->GET( "http://www.httpbin.org/get",
                          { { "name", "Alice" },
                            { "role", "admin" } } )
                  .exec()
                  .get_code();
  //
  std::cout << code << " " << http->get_body() << std::endl;
}

An asynchronous request later joined:

#include <curlev/http.hpp>
#include <iostream>

using namespace curlev;

int main( int argc, char ** argv )
{
  ASync async;
  async.start();
  //
  auto http = HTTP::create( async );
  http->GET( "http://www.httpbin.org/get", { { "id", "42" } } )
      .start();
  //
  int value;
  std::cout << "Enter a number:" << std::endl;
  std::cin >> value;
  //
  auto code = http->join().get_code();
  std::cout << code << " " << http->get_body() << std::endl;
}

The same using a std::future:

#include <curlev/http.hpp>
#include <iostream>

using namespace curlev;

int main( int argc, char ** argv )
{
  ASync async;
  async.start();
  //
  auto future = HTTP::create( async )->GET( "http://www.httpbin.org/get", { { "id", "42" } } )
                                      .launch();
  //
  int value;
  std::cout << "Enter a number:" << std::endl;
  std::cin >> value;
  //
  auto response = future.get();
  std::cout << response.code << " " << response.body << std::endl;
}

A request with callback, running detached:

#include <chrono>
#include <curlev/http.hpp>
#include <iostream>
#include <thread>

using namespace curlev;

void f( ASync & async )
{
  auto http = HTTP::create( async );
  http->GET( "http://www.httpbin.org/get" )
      .start( []( const HTTP & http )
              { std::cout << http.get_code() << " " << http.get_body() << std::endl; } );
}

int main( int argc, char ** argv )
{
  ASync async;
  async.start();
  //
  f( async );
  //
  std::this_thread::sleep_for( std::chrono::seconds( 1 ) );
}

The complete reference manual can be found here.

Installing and compiling

In order to compile curlev you will need the following:

• git
• cmake
• pkg-config
• a C++17 compiler
• libcurl (>=7.61.1 but with memory leaks and config problems, >=7.87.0 recommended)
• libuv
• optionally: RapidJSON or nlohmann/json

Here are the package names for some distributions:

Distribution	packages
Ubuntu	git, cmake, pkg-config, g++ or clang, libcurl4-openssl-dev or libcurl4-gnutls-dev, libuv1-dev
Suse	git, cmake, pkg-config, gcc-c++ or clang, libcurl-devel, libuv-devel
Oracle	git, cmake, pkgconf-pkg-config, g++, libcurl-devel, libuv-devel

In a terminal, execute the following commands:

git clone https://github.com/delperugia/curlev
cd curlev/
cmake      -B         build/  -DCMAKE_BUILD_TYPE=Release
cmake      --build    build/  -j
sudo cmake --install  build/

If RapidJSON or nlohmann/json are installed, extra REST methods will be available in the HTTP client.

Testing and debugging

For testing and debugging, you must also install the following packages:

• clang-tidy
• cppcheck (>=2.13)
• gtest
• nlohmann-json
• valgrind

In a console, execute the following:

git clone https://github.com/delperugia/curlev
cd curlev/
cmake -B         build/  -DCMAKE_BUILD_TYPE=Debug -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DBUILD_TESTING=ON
cmake --build    build/  -j
ctest --test-dir build/  -T test -T coverage
cmake --build    build/  --target cppcheck
cmake --build    build/  --target clang-tidy
cmake --build    build/  --target clean

Tested with:

	Suse 15	Oracle 8.6	Ubuntu 22.04	Ubuntu 24.04
g++		8.5.0		13.3.0
clang	7.0.1		14.0.0
libuv	1.44.2	1.41.1	1.43.0	1.48.0
libcurl	8.6.0	7.61.1	7.81.0	8.5.0