osx - How to read/write memory on Mac OS X with VBA? -


on windows declared function rtlmovememory provides way copy block of bytes 1 address another:

private declare ptrsafe sub rtlmovememory lib "kernel32" ( _                               byval dest longptr, _                               byval src longptr, _                               byval size longptr)

what equivalent on mac os x ?

what equivalent on mac os x ?

short answer:

private declare ptrsafe function copymemory lib "libc.dylib" alias "memmove" _                                  ( _                                     byval dest longptr _                                   , byval src longptr _                                   , byval size longlong _                                   ) _                         longptr

long answer: depends ;)

the following fledged example uses conditional compilation* allow work on mac/windows/32-bit/64-bit computer. demonstrates 2 different ways declare , call function (by pointer , variable).

#if mac   #if win64     private declare ptrsafe function copymemory_byptr lib "libc.dylib" alias "memmove" (byval dest longptr, byval src longptr, byval size long) longptr     private declare ptrsafe function copymemory_byvar lib "libc.dylib" alias "memmove" (byref dest any, byref src any, byval size long) longptr   #else     private declare function copymemory_byptr lib "libc.dylib" alias "memmove" (byval dest long, byval src long, byval size long) long     private declare function copymemory_byvar lib "libc.dylib" alias "memmove" (byref dest any, byref src any, byval size long) long   #end if #elseif vba7   #if win64     private declare ptrsafe sub copymemory_byptr lib "kernel32" alias "rtlmovememory" (byval dest longptr, byval src longptr, byval size longlong)     private declare ptrsafe sub copymemory_byvar lib "kernel32" alias "rtlmovememory" (byref dest any, byref src any, byval size longlong)   #else     private declare ptrsafe sub copymemory_byptr lib "kernel32" alias "rtlmovememory" (byval dest longptr, byval src longptr, byval size long)     private declare ptrsafe sub copymemory_byvar lib "kernel32" alias "rtlmovememory" (byref dest any, byref src any, byval size long)   #end if #else   private declare sub copymemory_byptr lib "kernel32" alias "rtlmovememory" (byval dest long, byval src long, byval size long)   private declare sub copymemory_byvar lib "kernel32" alias "rtlmovememory" (byref dest any, byref src any, byval size long) #end if   public sub copymemorytest()    dim abytdest(0 11) byte   dim abytsrc(0 11) byte   dim ¡ long    ¡ = lbound(abytsrc) ubound(abytsrc)     abytsrc(¡) = ascb("a") + ¡   next ¡    msgbox "dest before copy = #" & tostring(abytdest) & "#"   copymemory_byvar abytdest(0), abytsrc(0), 4   msgbox "dest during copy = #" & tostring(abytdest) & "#"   copymemory_byptr varptr(abytdest(0)) + 4, varptr(abytsrc(0)) + 4, 4   msgbox "dest during copy = #" & tostring(abytdest) & "#"   copymemory_byptr varptr(abytdest(8)), varptr(abytsrc(8)), 4   msgbox "dest after copy = #" & tostring(abytdest) & "#"  end sub  public function tostring(byref pabytbuffer() byte) string   dim ¡ long   ¡ = lbound(pabytbuffer) ubound(pabytbuffer)     tostring = tostring & chr$(pabytbuffer(¡))   next ¡ end function

explanation:

the mac version of copymemory function returns result whilst win version not. (the result dest pointer, unless error occurred. see memmove reference here.) both versions, however, can used in same way, without brackets.

the declare differences follows:

  • 64-bit mac/win vba7:

    • use ptrsafe keyword
    • use any type all byref parameters
    • use longptr type byval handle/pointer parameters/return values
    • use longlong type appropriately other return values/parameter

  • 32-bit win vba7:

    • use ptrsafe keyword
    • use any type all byref parameters
    • use longptr type byval handle/pointer parameters/return values
    • use long (not longlong) type appropriately other return values/parameter

  • 32-bit mac/win vba6:

    • no ptrsafe keyword
    • use any type all byref parameters
    • use long type byval handle/pointer parameters/return values
    • use long type appropriately other return values/parameter

caveats:

  • tested on mac excel 2016 64-bit.

  • tested on windows excel 2007 32-bit.

    • seems excel 2007 has issues related double word alignment. in example:

      copymemory_byvar abytdest(0), abytsrc(0), 4 '-> abcd copymemory_byvar abytdest(1), abytsrc(1), 8 '-> abcdefghi

      copymemory() skips copying until double word alignment reached (3 skips in case), continues copying 4th byte.

note: if curious variable naming convention, based on rvba.

*the correct way.


Comments

Post a Comment

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

i'm using class based views in django , never specify url in ajax calls , omit action parameter in form because know these requests go through post method of class based view. notice view - profile page make many requests depending on user updating on page - post method become convoluted , if/else mess example: def post(self, request, *args, **kwargs): # handle user changing available date if request.post.get('availabledate') != none: self.updateavailabledate(request) return jsonresponse({'result':'success'}) if request.post.get('newprojectname') != none: creative_user = creativeuserprofile.objects.get(id = request.user.id) project = project.create_project(creative_user, request.post['newprojectname']) project.save() return jsonresponse({'projectid': project.id }) if request.post.get('projectimage') != none , request.files['file']: proj...
Read more

What is happening when Matlab is starting a "parallel pool"? -

running parallel cpu processes in matlab starts command parpool() according documentation , function: [creates] special job on pool of workers, , [connects] matlab client parallel pool. this function takes bit of time execute, on order of 30 seconds. in other multi-cpu paradigms openmp, parallel execution seems totally transparent -- i've never noticed behavior analogous matlab (granted i'm not experienced parallel programming). so, happening between time parpool() called , when finishes executing? takes long? parallel computing toolbox enables run matlab code in parallel using several different paradigms (e.g. jobs , tasks, parfor , spmd , parfeval , batch processing), , run either locally (parallelised across cores in local machine) or remotely (parallelised across machines in cluster - either 1 own, or 1 in cloud). in of these cases, code run on matlab workers , copies of matlab without interactive desktop. if you're intending run on remo...
Read more

php - Cannot override Laravel Spark authentication with own implementation -

during login process of laravel spark need request token of remote api. api stores exact same users , passwords laravel spark application. therefore need username , non hashed password of user during authentication process. i thought overriding authenticated method solution problem. in routes/web.php override post /login endpoint , pointing endpoint own logincontroller: <?php namespace app\http\controllers\auth; use illuminate\support\facades\log; use illuminate\http\request; use laravel\spark\http\controllers\auth\logincontroller sparklogincontroller; class logincontroller extends sparklogincontroller { /** * create new login controller instance. * * @return void */ public function __construct() { parent::__construct(); } /** * handle successful authentication attempt. * * @param request $request * @param \illuminate\contracts\auth\authenticatable $user * @return response */ public fu...
Read more