iea has asked for the wisdom of the Perl Monks concerning the following question:

Hi, i am trying to use the wingapi.dll with perl - here the dll function for C 
HANDLE
WINAPI
WIMCreateFile(
    LPWSTR  lpszWimPath,
    DWORD   dwDesiredAccess,
    DWORD   dwCreationDisposition,
    DWORD   dwFlagsAndAttributes,
    DWORD   dwCompressionType,
    LPDWORD lpdwCreationResult
    );

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Here my code ... 
use Win32::API;
use Data::Dumper;
use FileHandle;

#Open Filehandler
$fh = new FileHandle;
if ($fh->open("< C:\\data.wim")) {
  $fh->close;
}

my $wimfile = new Win32::API("wimgapi", "WIMCreateFile", ['P','C','C',
+'C','C','C'], 'N');
my $value = $wimfile->Call($fh,WIM_GENERIC_WRITE,WIM_OPEN_EXISTING,WIM
+_FLAG_VERIFY,WIM_COMPRESS_NONE,WIM_OPENED_EXISTING);

print $value;
#Returns:
#         0

print Dumper($wimfile);
#Returns: 
# $VAR1 = bless( {
#                  'out' => 1,
#                  'dll' => 1940783104,
#                  'procname' => 'WIMCreateFile',
#                  'proc' => 1940839096,
#                  'dllname' => 'wimgapi',
#                  'in' => [
#                            2,
#                            6,
#                            6,
#                            6,
#                            6,
#                            6
#                          ]
#                }, 'Win32::API' );

# I: value is an integer (int)
# N: value is a number (long)
# F: value is a floating point number (float)
# D: value is a double precision number (double)
# C: value is a char (char)
# P: value is a pointer (to a string, structure, etc...)
# S: value is a Win32::API::Struct object (see below)
# K: value is a Win32::API::Callback object (see Win32::API::Callback)

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I dont know if its even possible to call function from the wimgapi. Thanks

Replies are listed 'Best First'.
Re: Use Windows wimgapi dll
by Anonymous Monk on Jul 31, 2008 at 06:05 UTC
    Where does WIM_GENERIC_WRITE.. come from? 
    use strict;
use warnings;

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Re: Use Windows wimgapi dll
by Anonymous Monk on Jul 31, 2008 at 06:12 UTC
    If you add 
    print $fh;

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    You'll get something resembling FileHandle=GLOB(0x1990c80) not C:\data.wim as you probably wanted.
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Re: Use Windows wimgapi dll
by ikegami (Patriarch) on Jul 31, 2008 at 07:03 UTC

    The first argument is a wide character string (LPWSTR), but you pass a Perl glob object. I imagine you'd need to pass the result of the following: 

    use Encode qw( encode );
encode('UCS-2le', 'C:\\data.wim')

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    Why do you open a file only to immediately close the handle?

    I also wonder why you FileHandle is used over the simpler and safer open. 

    use FileHandle qw( );
my $fh = new FileHandle;
$fh->open("< C:\\data.wim")
   or die;

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    vs 

    open(my $fh, "<", "C:\\data.wim")
   or die;

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    (Add use IO::Handle; if you want to use $fh like an object.)

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      Hi, thanks for your fast replies and sry for my delay.
      >>Where does WIM_GENERIC_WRITE.. come from?
      They are defined in the wimgapi doc, you can find them with waik.

      @ikegami I did try a simple open ... I added your encode line but it still doesnt work. 
      use Encode qw( encode );
my $filehandler = encode('UCS-2le', 'C:\\data.wim');

my $wimfile = new Win32::API("wimgapi", "WIMCreateFile", ['S','C','C',
+'C','C','C'], 'N');
my $value = $wimfile->Call($filehandler,WIM_GENERIC_WRITE,WIM_OPEN_EXI
+STING,WIM_FLAG_VERIFY,WIM_COMPRESS_NONE,WIM_OPENED_EXISTING);

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      i get following errorcode... 
      semi-panic: attempt to dup freed string at test.pl line 10, <DATA> lin
+e 164.
Can't call method "Pack" on an undefined value at test.pl line 10, <DA
+TA> line 164.

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      anybody knows what i´m doing wrong?
      thanks for your help
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        thanks for your answer ... I added "\0" to the string but there is no change. I dont get any error message it just returns 0 as filehandle. my $hWim = $wimfile->Call(... #returns 0 see code above
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