Re: Call a function from DLL

Hello Cleware and welcome to the monstery and to the wonderful world of perl!

I suspect nothing is wrong with your import: the error Undefined subroutine &main::Print refers to your statement Print($return); infact in perl you have print not Print and no parens are needed (or you'll get another error like print interpreted as function at.. ).

Also do not never forget to use strict; use warnings; at the top of your perl programs.

As per the Win32::API docs is good to check if the import was done (the two die in the below code):

use Win32::API;
$function = Win32::API::More->new(
    'mydll', 'int sum_integers(int a, int b)'
);

#### $^E is non-Cygwin only
die "Error: $^E" if ! $function;
#### or on Cygwin and non-Cygwin
die "Error: ".(Win32::FormatMessage(Win32::GetLastError())) if ! $func
+tion;
[download]

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Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.

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Re^2: Call a function from DLL by Cleware (Novice) on Jul 15, 2019 at 07:49 UTC
Dear Discipulus, Thank you very much for offering to help, Actually the I have another question: the idea is , I want to call the function FCWIntiObject() and the return value must be as object. then I want to call the second function int FCWOpenCleware(object*) which it takes the return value from the previous function as an argument. could you help me? thanks in advance.	[reply]
Re^3: Call a function from DLL by GrandFather (Saint) on Jul 15, 2019 at 08:18 UTC
Dealing with C++ (as opposed to C) function calls is something of a problem because the C++ compiler mangles function names to allow for function overloading and such C++ magic. Name mangling tends to be rather specific to individual C++ compilers as are calling conventions. You need some very specific information about the compiler you are using to even call the functions. Passing objects back and forth may either be easy (if you treat them as completely opaque objects) or potentially very complicated if you need to get involved in memory management and accessing parts of the object. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply]
Re^4: Call a function from DLL by Cleware (Novice) on Jul 15, 2019 at 10:24 UTC
I would thank you for your reply, but acutely I have no idea to do that in Perl Do you have any suggestion? thanks in advance	[reply]
Re^5: Call a function from DLL by GrandFather (Saint) on Jul 16, 2019 at 00:51 UTC
Re^3: Call a function from DLL by holli (Abbot) on Jul 15, 2019 at 08:45 UTC
Your best bet is probably to nest calls, as in `$FCWOpenCleware->Call( $FCWIntiObject->Call() )` [download] holli You can lead your users to water, but alas, you cannot drown them.	[reply] [d/l]