in reply to Problems with Win32::API module

My guess is that $LLHandle is first 'introduced' within your code by the call of Call($LLHandle) and thus is undefined. The use of strictures, i.e. 

#!/usr/bin/perl

use strict; 
use warnings;

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would have caught that though.

Unless $LLHandle is exported per default by Win32::API, which I don't know. But I saw no mention of $LLHandle in Win32::API's documentation.

Perhaps you accidentally forgot to include some relevant code?

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Re^2: Problems with Win32::API module
by Anonymous Monk on May 01, 2007 at 12:48 UTC
    Here is the corrected code.. my fault: 
    #!/usr/bin/perl

use Win32::API;

my $lpBuffer = "\0" x 64;

my $ZP4StartSession = new Win32::API("ZP4", "ZP4StartSession", [N], P)
+ || die Win32::FormatMessage(Win32::GetLastError);

my $LLHandle = $ZP4StartSession->Call($lpBuffer) || die Win32::FormatM
+essage(Win32::GetLastError);

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      The "N" in "[N]" causes $lpBuffer to be interpretted as a number. "\0" x 64 as a number is just 0. Although you tell us nothing about ZP4StartSession(), it appears clear that what you want to pass to it is a pointer to the buffer you allocated in $lpBuffer. Win32::API doesn't support this type of argument very well / easily. It only supports pointers to '\0'-terminated strings.

      However, it might work to use [P] instead. That depends on implementation details of Win32::API that I am not certain of.

      If that doesn't work, then you should probably do: 

      my $lpBuffer= "\0" x 64;
my $bufAddr= unpack "L", pack "p", $lpBuffer;
#...
... $ZP4StartSession->Call( $bufAddr ) ...

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      - tye        

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