comment on

Very nice and Very handy package.
I'm having a problem, however... :-)

In short, I'm trying to use Win32::API to call CreateProcess.

All is well except for the LPSTARTUPINFO and LPPROCESS_INFORMATION parms I pass into the call. If I create these using pack(...) for the correct number of bytes, it works fine and I can get the PID back out of the PROCESS_INFORMATION object (my ultimate goal).

If, however, I create these parms using the Win32::API::Struct->new( 'STARTUPINFO' ) approach, the call fails. I'm even setting the .cb field to the size of the structure. The error I get back (using Win32::GetLastError()) is "Invalid access to memory location". Here's the function call I'm making (same in both cases):

<-----------snip------------>

# version 1 - succeeds
my $si = pack( "L17", ((0) x 17) );
$si = pack( "LL16", length( $si ), ((0) x 16 ) );
my $pi = pack( "L4", ((0) x 4 ) );

# version 2 - fails
my $si = Win32::API::Struct->new( "STARTUPINFO" );
$si->{cb} = $si->sizeof();
my $pi = Win32::API::Struct->new( "PROCESS_INFORMATION" );

my $retval =
CreateProcess( "c:\\winnt\\notepad.exe",
               0,    # unused - cmdline ptr, unused
               0,    # unused - proc attributes ptr
               0,    # unused - thread attributes ptr
               0,    # unused - inherit handles
               0,    # unused - creation flags
               0,    # unused - env pointer
               0,    # unused - current dir ptr
               $si,
               $pi
             );

<-----------snip------------>
[download]

Should CreateProcess be called the same way in both cases? When a ->new('STARTUPINFO') is called, is the memory zeroed-out upon creation? Any idea why the pack version succeeds and the Struct verion fails?

TIA!
D. Smith

In reply to Re: Re: Win32::API (finally) by neauva
in thread Win32::API by Guildenstern

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