I am trying to call a function within a DLL using Win32::API and am trying to do using Import and prototypes.
The parameters required by the function are all custom types, and so after reading the C header files and Win32::API::Type I have defined these types and Imported the function:
use strict; use Win32::API; Win32::API::Type->typedef( 'OMDTEXTZ', 'TCHAR'); Win32::API::Type->typedef( 'OMDERROR', 'ULONG'); Win32::API::Type->typedef( 'OMD32U', 'ULONG' ); Win32::API::Type->typedef( 'OMDCLIENT', 'ULONG' ); Win32::API->Import( 'omdapi', 'OMDERROR OMDClientCreate ( OMDTEXTZ* pUsername, OMDTEXTZ* pPassword, OMDTEXTZ* pDomain, OMD32U options, OMDCLIENT* pClient )' ); ## my $return = OMDClientCreate( "OMG, I am so confused!" );
My question is: how am I supposed to call OMDClientCreate? When the C function wants a OMDTEXTZ* do I simply give it a Perl string? What about when it wants a OMDCLIENT* to return me the client handle?
I have found little to no documention in either Win32::API or Win32::API::Type to explain how this is done.
Thanks,
fx, Infinity is Colourless
Yes. Just pass perl variables (NOT constants!) for each of the parameters.
...
my $uname = 'USER1';
my $passw = 'PASS';
my $domain = 'DOMAIN';
## use constant NICE_OPT_NAME => 128; etc. if you want symblic names
my $options = 128 | 16 | 2;
my $client;
OMDClinetCreate( $uname, $passw, $domain, $options, $client )
or die $^E; ## Add this to your other calls also!.
The whole reason for using teh typedefs is that it allows the module to do the required conversion work for you.
"Think for yourself!" - [Abigail-II|Abigail]
"Memory, processor, disk in that order on the hardware side. Algorithm, algoritm, algorithm on the code side." - [tachyon]
I still can't get it to work with Import. As you suggest, I have tried:
use strict; use Win32::API; Win32::API::Type->typedef( 'OMDTEXTZ', 'TCHAR'); Win32::API::Type->typedef( 'OMDERROR', 'ULONG'); Win32::API::Type->typedef( 'OMD32U', 'ULONG' ); Win32::API::Type->typedef( 'OMDCLIENT', 'ULONG' ); Win32::API->Import( 'omdapi', 'OMDERROR OMDClientCreate ( OMDTEXTZ* pUsername, OMDTEXTZ* pPassword, OMDTEXTZ* pDomain, OMD32U options, OMDCLIENT* pClient )' ); my $username = 'user1'; my $password = 'pass1'; my $domain = 'domain1'; my $options = 0; my $client; my $return = OMDClientCreate( $username, $password, $domain, $options, $client ) or die $^E;
And although the call to OMDClientCreate does not die, it also puts nothing into the $client variable.
However, if I try it using a parameter list instead:
use strict;
use Win32::API;
my $function = Win32::API->new( 'omdapi', 'OMDClientCreate', 'PPPIP', 'I');
my $client = pack('L', 0);
my $username = 'user1';
my $password = 'pass1;;
my $domain = 'domain1';
my $return = $function->Call( $username, $password, $domain, 0, $client );
it actually works (which I have confirmed by using Data::Dumper on the $client variable).
Am I missing something?
Thanks,
fx, Infinity is Colourless
I suspect that the problem is that TCHAR is not a type that Win32::API::Type knows about. You can find the list of those that it does know about at the bottom of the Type.pm source file.
You probably need to change
Win32::API::Type->typedef( 'OMDTEXTZ', 'TCHAR');
to something like
Win32::API::Type->typedef( 'OMDTEXTZ', 'unsigned char')
or die $^E;
However, if you were to add some error checking to your calls (as above and in my original snippet. E.g. ...or die $^E;), then the module would be telling you what is wrong and where.
According to the source, TCHAR is a valid type which is why I chose it. Hmm...
As you suggest, I shall put lots of error checking in and see what isn't being liked.
Thanks,
fx, Infinity is Colourless
Ok, I've just added ...or die $^E to every Win32::API module call and nothing is die'ing. As far as I can see the call to the function inside the DLL is actually working
Hmm...
fx, Infinity is Colourless
Try initializing my $client = pack('L', 0); as you did in the code that worked.
Warning: you may have to sacrifice livestock or perform some strange ritual in a musty basement in order to get everything working.
-vlad
my $FileTimeToSystemTime = new Win32::API('Kernel32.dll', 'FileTimeToSystemTime',['P','P'],'I');
sub FileTimeToSystemTime {
my $filetime=shift;
my $systemtime="\0" x (2*8);
$FileTimeToSystemTime->Call($filetime, $systemtime) or return;
return unpack( 'S8', $systemtime);
}
I'm not sure if this would help in your case, but I have successfully used Dave Roth's Win32::API::Prototype when making Win32 API calls. It just makes it a bit easier.
chinman