in reply to Re: Win32 Shared Memory
in thread Win32 Shared Memory

Yer, I would if I knew what functions to import and from where :(

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Re: Re: Re: Win32 Shared Memory
by BrowserUk (Patriarch) on May 15, 2004 at 08:22 UTC

    The first page you linked to contains pretty much all you need to locate that information.

    Example:

    HANDLE memory_handle = OpenFileMapping(MAP_FILE_ALL_ACCESS, FALSE, "Creatures 3_mem");

    Googling for "OpenFileMapping MSDN" brings up http://msdn.microsoft.com/library/en-us/fileio/base/openfilemapping.asp as the first link. Pasting the prototype given at the top of the page into Win32::API::Prototype along with "Kernel32.dll" located near the bottom, and supply the constants and you should be able to get access to the shared memory segement (assuming you have whatever application creates it running on your machine).

    A similar process for each of the other APIs listed at your link would get you a long way towards your goal.


    Examine what is said, not who speaks.
    "Efficiency is intelligent laziness." -David Dunham
    "Think for yourself!" - Abigail
      Ok, I tried that. BUT... (oh no...)

      I get this error: Modification of a read-only value attempted at C:/Perl/site/lib/Win32/API/Type.pm line 195, <DATA> line 164.

      Here's my code:

      use Win32::API; my $STANDARD_RIGHTS_REQUIRED = (0x000F0000); my $SECTION_QUERY = 0x0001; my $SECTION_MAP_WRITE = 0x0002; my $SECTION_MAP_READ = 0x0004; my $SECTION_MAP_EXECUTE = 0x0008; my $SECTION_EXTEND_SIZE = 0x0010; my $SECTION_ALL_ACCESS = ($STANDARD_RIGHTS_REQUIRED|$SECTION_Q +UERY| $SECTION_MAP_WRITE |$SECTION_MAP +_READ| $SECTION_MAP_EXECUTE |$SECTION_EXT +END_SIZE); Win32::API->Import('kernel32', 'HANDLE OpenFileMapping(DWORD dwDesired +Access, BOOL bInheritHandle, LPCTSTR lpName)'); my $foo = OpenFileMapping($SECTION_ALL_ACCESS, 0, "Creatures 3_mem");

        The problem is your passing a string constant for the last parameter of OpenFileMapping(). Seems like it would be a safe bet I know, given that the prototype is defined as LPCTSTR.

        The problem is that the C code underlying the API is expecting strings to be null terminated and Perls strings aren't by default. To correct this, Win32::API has to add a null before passing them along. Rather than copying the string you pass into a temporary variable and then appending the null, it simply tacks a null on the end of the string you pass--but if it is a constant, it's read-only and you get the error.

        The upshot is, if you assign your constant to a variable, and then pass the variable, then null can be added successfully and the error goes away.


        Examine what is said, not who speaks.
        "Efficiency is intelligent laziness." -David Dunham
        "Think for yourself!" - Abigail