OpenEuphoria

=Euphoria DLL Howto
\\
Here is an introduction to **writing** a dll using Euphoria.\\
This is not to be confused with **using** an existing Windows dll or Linux .so library.
I've entered here, because the topic was empty. Here is the newbie's investigation of how to use dll in euphoria code. Hope this will help to newbies, and also hope that some guru help this topic to be extended with additional examples and let us understand it deeper and painless.

== Tools needed
* Euphoria 4.02
* Openwatcom C win32 1.9

== Step 1. Creating a simple DLL using Euphoria
Open your favorite text editor an enter following lines:
<eucode>
include std/console.e
constant SCREEN = 1

global procedure HelloWorld()
puts(SCREEN, " \n Hello, World! \n")
any_key()
end procedure
</eucode>
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Now, save the file with targetDLL.ex name.
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Open command prompt, navigate to the folder where targetDLL.ex located (leave it opened for further usage).
Translate the Euphoria code to C and compile it as DLL using following command:
{{{
euc -con -dll targetDLL.ex
}}}
Where:
* euc - is a Euphoria to C translator
* -con - to state that we do not want the GUI
* -dll - to state that we want to create a DLL

You should see the output like following:
{{{
Build directory: build-433938\
Translating code, pass: 1 2 3 4 generating
Compiling with Watcom
Compiling 1% init-.c
Compiling 7% targetDLL.c
Compiling 11% main-.c
Compiling 15% console.c
Compiling 19% get.c
Compiling 23% error.c
Compiling 26% io.c
Compiling 30% machine.c
Compiling 34% memconst.c
Compiling 38% memory.c
Compiling 42% dll.c
Compiling 46% types.c
Compiling 50% text.c
Compiling 53% convert.c
Compiling 57% search.c
Compiling 61% filesys.c
Compiling 65% datetime.c
Compiling 69% math.c
Compiling 73% rand.c
Compiling 76% sequence.c
Compiling 80% sort.c
Compiling 84% wildcard.c
Compiling 88% pretty.c
Compiling 92% serialize.c
Compiling 96% graphcst.c
Linking 100% ..\targetDLL.dll
}}}

The test DLL is ready, we can go to next step.

== Step 2. Using your external DLL with a Euphoria program
== Step 2. Using external DLL with Euphoria program
Open the text editor and enter following lines:
<eucode>
include std/dll.e

atom thedll
integer theroutine

-- step 1. Open the DLL
thedll = open_dll("targetDLL.dll")
-- step 2. Define the routine inside the DLL
theroutine = define_c_proc(thedll , "HelloWorld", {})
-- step 3. Execute the routine
c_proc(theroutine)
</eucode>
Now, save the file with openDLL.ex name, and execute it in command prompt:
{{{
openDLL.ex
}}}
You should see the output like following:
{{{
Hello, World!
Press Any Key to continue...
}}}

== Conclusion
Thats all. We called C procedure {{{"HelloWorld"}}}, stored in compiled DLL file from the Euphoria program. This is the basics, it does not cover how to handle the variables, it does not cover how to deal with "real" C/{{{C++}}} coded DLLs, and I'd like that basics will be extended in following way:
Thats all. We called C procedure "HelloWorld", stored in compiled DLL file from the Euphoria program. This is the basics, it does not cover how to handle the variables, it does not cover how to deal with "real" c/cplusplus coded DLLs, and I'd like that basics will be extended in following way:
\\
\\
* Include some variables to deal with it
* Build the test DLL using C-source code and with MinGW
* Build the test DLL using C++ source code and with MinGW
* Finally (to make it brilliant) create a real step by step example based on some popular DLL (ex. lame)