luasocket

A luasocket module that works on Windows with lua 5.3 and 5.4 (select the appropriate package in releases)

So far, so good, but when you work under Windows it becomes really difficult to get the binaries for this luasocket module, as it is C based:

• I need the module under Windows
• I need it in Win32 and also x64 release
• I have Visual Studio 2017 Community Edition

I searched and searched, stumbled on LuaRocks - The Lua package manager, but never made it to correctly get this module, in the right release, compiled with Visual Studio...

A building solution of mine

So I patched together all the information I managed to get accross the net and I created this procedure. After many tries with luarocks, I realized that the sources of the luasocket module where correctly downloaded, but not built at all.

• with 7-zip, unzip of the file "luasocket-3.0rc1-2.src.rock", precisely, the path "luasocket-3.0rc1-2.src.rock\v3.0-rc1.zip\luasocket-3.0-rc1"
• copy of "Lua53.props" to "Lua.props"
• update of the paths in the projects to match the correct options for Visual Studio 2017
• the type lua library linked with the luasocket module must be configured in the "Lua.props" file

  <PropertyGroup Label="UserMacros">
...
	  <!-- For dynamic or static lua library linking -->
	  <!-- Uncomment one of those 2 lines -->
    <!-- <LUALIB>lua53.lib</LUALIB> -->
    <LUALIB>lua53-static.lib</LUALIB>
  </PropertyGroup>

• you can choose to make it (personaly I prefer static, as it avoids the hassle of managing the lua libraries path):
  • dynamic, and in this case, the "lua53.dll" must be findable somewhere in the PATH of the application using the "luasocket" module
  • static, and then the "luasocket" module is self sufficient, no other DLLs are needed
• the build structure has been re-arranged to include the build target architecture in the build path, with Win32 or x64 possibilities
• the "lua" binaries and includes paths must be configured correctly in "Lua.props", for example here, with a relative path:

  <PropertyGroup Label="UserMacros">
    <LUA_PATH>..\..\lua\sources\lua53\</LUA_PATH>
...
  </PropertyGroup>

• finally, open "luasocket.sln" solution in "Visual Studio 2017"
• choose the type of build (I suggest "Release") and the desired architecture (among "Win32" or "x64")
• rebuild the solution. The binaries and lua scripts for the "luasocket" module are available under either: luasocket\Release\Win32 or luasocket\Release\x64

Building with only VS 2022 Development kit

As times are changing, I switched from the good, but oversized, Visual Studio to the lightweight and versatile VS Code.
This switch implies to build C++ applications without the ease of Visual Studio: enters MsBuild.
You need to install the C++ extension for VS Code, with the Software Development kit corresponding, here for Visual Studio 2022.

The needed modifications in the projects .vcxproj files are following:

• modify the WindowsTargetPlatformVersion to something less constraining (one occurence)

    <Keyword>Win32Proj</Keyword>
    <WindowsTargetPlatformVersion>10.0</WindowsTargetPlatformVersion>

• set the PlatformToolset to the matching Development kit (several occurences)

    <PlatformToolset>v143</PlatformToolset>

The build is done with the following command, by passing the additional arguments for the Configuration and the Target:

• in a console, start the matching development environment (among Win32 or x64)

"C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvars32.bat"
REM OR
"C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvars64.bat"

msbuild -version

• launch the build of the projects

MSBuild luasocket.sln /property:Configuration=Release /property:Platform=Win32
REM OR
MSBuild luasocket.sln /property:Configuration=Release /property:Platform=x64

A script does this in a shorter way:

Build-luasocket.cmd Win32
REM OR
Build-luasocket.cmd x64

The binaries are available under: .\Release\Win32 or .\Release\x64

Modifications made to original luasocket

The original "luasocket" module code didn't build out of the box in "Visual Studio 2017", I had to make several modifications:

• for both projects "socket" and "mime", in their "Properties"
  • tab "C/C++", "General"
  • modify "$(LUAINC_PATH)" to "$(LUA_PATH)$(Platform)\include" in "Additional Include Directories"
  • tab "C/C++", "Command Line"
  • add "/FS" in "Additional Options"
  • tab "Linker", "General"
  • modify "$(OutDir)$(TargetName).dll" to "$(Configuration)$(Platform)$(ProjectName)$(TargetName).dll" in "Output File"
  • modify "$(LUALIB_PATH)" to "$(LUA_PATH)$(Platform)\lib" in "Additional Library Directories"
• for all the ".lua" files present in the directories "cdir" and "ldir" of each project
• right clic on "Properties", for the "cdir"
  • tab "Custom Build Tool", "General"
  • modify "Command Line" to:

copy %(FullPath) $(Configuration)\$(Platform)\

• modify "Outputs" to "$(Configuration)$(Platform)%(Filename)%(Extension)"
• right clic on "Properties", for the "ldir"
  • tab "Custom Build Tool", "General"
  • modify "Command Line" to:

copy %(FullPath) $(Configuration)\$(Platform)\$(ProjectName)\

• modify "Outputs" to "$(Configuration)$(Platform)$(ProjectName)%(Filename)%(Extension)"

The C source code of the "luasocket" module was also not lua 5.3 ready, I did following modifications to ensure lua 5.3 compatibility:

• added this piece of code at the beginning of those 2 source files "luasocket.c" and "mime.c"

/*=========================================================================*\
* ARi - Needed for lua 5.3 compatibility
\*=========================================================================*/
#ifndef luaL_checkint
#define luaL_checkint(L, n) ((int)luaL_checkinteger(L,n))
#endif

Correction of the receive error after lua 5.4.3

From lua 5.4.3 on there is an error in the calls to the receive method:

lua54.exe: exclient.lua:10: bad argument #1 to 'receive' (string expected, got light userdata)
stack traceback:
        [C]: in method 'receive'
        exclient.lua:10: in main chunk
        [C]: in ?

A correction/patch has been provided in the official luasocket GitHub - lunarmodules/luasocket: Network support for the Lua language
The complete set of sources in src has been refreshed with the content of luasocket-3.1.0-1.src.rock\luasocket\src\ in the rockspec of release 3.1.0, downloaded from luasocket-3.1.0-1.src.rock

Basic tests with TCP connection

I wrote a basic script to test a simple message over a TCP connection. There are plenty of scripts to furtherly test some more commplicated functions, for instance in luasocket/samples at master · lunarmodules/luasocket · GitHub

Once you have built lua54.exe and luasocket, proceed following:

• copy the script tcpsample.lua to the luasocket directory: luasocket\Release\Win32 or luasocket\Release\x64
• open 2 consoles on this directory, one for the listener and the second for the client (sends a message)
• in the listener console, launch:

..\..\..\lua54\x64\bin\lua54.exe -e "require('tcpsample').listen('127.0.0.1', 6060)"

• in the client console, launch:

..\..\..\lua54\x64\bin\lua54.exe -e "require('tcpsample').sample('127.0.0.1', 6060, 'Hello guys')"

• check that the message is correctly received in the listener console, it should look like this

TCP listen on: 127.0.0.1:6060    (Ctrl+C to quit...)
Hello guys
-- debug: closed