Re^4: Using Inline::C in a package

[syphilis]

You'll need to wrap the C handle in a bless reference

Actually, I think you can just return the HANDLE to perl with newSVuv().
I certainly have a script that passes a HANDLE between perl and C (in both directions) as a UV, and it works fine:

use warnings;
use strict;

use Inline C => Config =>
    BUILD_NOISY => 1;

use Inline C => <<'EOC';

SV * get_handle() {
     return newSVuv(GetStdHandle(STD_OUTPUT_HANDLE));
}

SV * get_attr(SV * h) {
     CONSOLE_SCREEN_BUFFER_INFO Info;
     if(!GetConsoleScreenBufferInfo((HANDLE)SvUV(h), &Info))
       croak("Error obtaining current attributes");
     return newSVuv(Info.wAttributes); 
}

void set_attr(SV * h, SV * attr) {
    if(!SetConsoleTextAttribute((HANDLE)SvUV(h), (WORD)SvUV(attr)))
      croak("Error setting attributes");
}

EOC

use constant {
 FOREGROUND_BLUE      => 1,
 FOREGROUND_GREEN     => 2,
 FOREGROUND_RED          => 4,
 FOREGROUND_INTENSITY => 8,
 BACKGROUND_BLUE      => 16,
 BACKGROUND_GREEN     => 32,
 BACKGROUND_RED       => 64,
 BACKGROUND_INTENSITY => 128};

$| = 1;
my $h = get_handle();
my $current = get_attr($h);

my $current_background = $current & (BACKGROUND_RED | BACKGROUND_BLUE
                         | BACKGROUND_GREEN | BACKGROUND_INTENSITY);

# $current_foreground not needed in this script
my $current_foreground = $current & (FOREGROUND_RED | FOREGROUND_BLUE
                         | FOREGROUND_GREEN | FOREGROUND_INTENSITY);

# Set $message to intense red on current background
my $message = FOREGROUND_RED | FOREGROUND_INTENSITY | 
              $current_background;

set_attr($h, $message);
print "ERROR_MSG = xyz";

# Restore original foreground/background colours.
set_attr($h, $current);
print "\n All Done\n";

(On Windows, that script just prints "ERROR_MSG = xyz" in bold red, then "All Done" in the original console color.)

So ... for the OP, I'm thinking if it's desired that OpenDevice() returns the handle, then it just needs to be:

SV * OpenDevice() {
  HANDLE handle;
  /* Do stuff that creates the handle */
  return newSVuv(handle);

And to pass that handle from perl back to C:

void pass_handle(SV * handle) {
  HANDLE h = (HANDLE)SvUV(handle);
  /* Do stuff with the handle */
}

Alternatively, it can be passed around just as well as an unsigned long:

unsigned long OpenDevice() {
  HANDLE handle;
  /* Do stuff that creates the handle */
  return (unsigned long)handle;

And to pass that handle from perl back to C:

void pass_handle(unsigned long handle) {
  HANDLE h = (HANDLE)handle;
  /* Do stuff with the handle */
}

That seems to be all that's needed - for any HANDLEs I've passed around, at least.

Cheers,
Rob