Re^2: Problems with Win32::API module

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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Comment on Re^2: Problems with Win32::API module Download Code

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Re^3: Problems with Win32::API module (addr) by tye (Sage) on May 01, 2007 at 16:17 UTC
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 ) ...` [download] - tye	[reply] [d/l] [select]

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Re^3: Problems with Win32::API module (addr)
by tye (Sage) on May 01, 2007 at 16:17 UTC

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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