In order to build the code you need CMake version 3.0 or higher on your system. Build as follows:

$ git clone https://github.com/vrtql/websockets.git
$ cd websockets
$ cmake .
$ make
$ sudo make install

Unit tests are located in test. As a basic test of operation, you can run the test_websockets test. To run it, first start the server as follows:

$ cd test
$ ./server

This is just a simple echo server example from the Mongoose project, used for testing. There is simple Mongoose-based client program in the test directory as well called client which can be used to test general connectivity. After the server is started, run test_websockets to see that everything is working:

$ ./test_websockets
TEST 1/4 test:send_receive

+----------------------------------------------------+
| Frame Sent                                         |
+----------------------------------------------------+
  header:   6 bytes
  fin:      1
  opcode:   1
  mask:     1 (0xb95d570f)
  payload:  7 bytes

da 32 39 7b dc 33 23
------------------------------------------------------

+----------------------------------------------------+
| Frame Received                                     |
+----------------------------------------------------+
  header:   2 bytes
  fin:      1
  opcode:   1
  mask:     0 (0x00000000)
  payload:  7 bytes

  .
  .
  .

This will connect to the server and run various send/receive tests dumping the frames sent to and received from the server to the console.

You must have the requisite MinGW compiler and tools installed on your system. For Debian/Devuan you would install these as follows:

$ sudo apt-get install mingw-w64 mingw-w64-tools mingw-w64-common \
                  g++-mingw-w64-x86-64 mingw-w64-x86-64-dev

You will need to have OpenSSL for Windows on your system as well. If you don't have it you can build as follows. First download the version you want to build. Here we will use openssl-1.1.1u.tar.gz as an example. Create the install directory you intend to put OpenSSL in. For example:

$ mkdir ~/mingw

Build OpenSSL. You want to ensure you set the --prefix to the directory you specified above. This is where OpenSSL will install to.

$ cd /tmp
$ tar xzvf openssl-1.1.1u.tar.gz
$ cd openssl-1.1.1u
$ ./Configure --cross-compile-prefix=x86_64-w64-mingw32- \
              --prefix=~/mingw shared mingw64 no-tests
$ make
$ make DESTDIR=~/mingw install

Now within the websockets project. Modify the CMAKE_FIND_ROOT_PATH in the config/windows-toolchain.cmake file to point to where you installed OpenSSL. The line to modify is shown in bold below:

set(CMAKE_SYSTEM_NAME Windows)
set(TOOLCHAIN_PREFIX x86_64-w64-mingw32)

# cross compilers to use for C, C++
set(CMAKE_C_COMPILER ${TOOLCHAIN_PREFIX}-gcc)
set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PREFIX}-g++)
set(CMAKE_Fortran_COMPILER ${TOOLCHAIN_PREFIX}-gfortran)
set(CMAKE_RC_COMPILER ${TOOLCHAIN_PREFIX}-windres)

# Set to where you have it installed
set(CMAKE_FIND_ROOT_PATH "/home/bubba/mingw/openssl")

# modify default behavior of FIND_XXX() commands
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

In this example it would be ~/mingw/openssl (you might want to use full path). Then invoke CMake as follows:

$ cmake -DCMAKE_TOOLCHAIN_FILE=config/windows-toolchain.cmake

Then build as normal:

  $ make