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when we type a command on DOS window to execute a exe file, i.e.
regedit.exe
OS actually searches from a set of directories, if the file is not found, it shows error.
Do you know full list and searchong order of these directories?
thanks
includeh10
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Per MSDN:
If the file name does not contain a directory path, the system searches for the executable file in the following sequence:
1) The directory from which the application loaded.
2) The current directory for the parent process.
3) Windows 95/98/Me: The Windows system directory. Use the GetSystemDirectory function to get the path of this directory.
Windows NT/2000/XP: The 32-bit Windows system directory. Use the GetSystemDirectory function to get the path of this directory. The name of this directory is System32.
4) Windows NT/2000/XP: The 16-bit Windows system directory. There is no function that obtains the path of this directory, but it is searched. The name of this directory is System.
5) The Windows directory. Use the GetWindowsDirectory function to get the path of this directory.
6) The directories that are listed in the PATH environment variable.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Hi DavidCrow,
thanks for extra info.
did you copy the info from MSDN?
two things need to know:
1. how to get "The directories that are listed in the PATH environment variable"?
2. "The current directory for the parent process" - what does it mean?
includeh10
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includeh10 wrote:
did you copy the info from MSDN?
Yes, see this function, about 1/3 of the way down.
includeh10 wrote:
1. how to get "The directories that are listed in the PATH environment variable"?
To get the contents of any environment variable, use GetEnvironmentVariable().
includeh10 wrote:
2. "The current directory for the parent process" - what does it mean?
Exactly what it says.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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if for CreateProcess() ...
lets say:
c:\dir0\parent.exe and child.exe
CreateProcess(NULL,"child.exe",...) is called by parent.exe
1)The directory from which the application loaded.
2)The current directory for the parent process.
the 1) is c:\dir0 definitely.
the 2) should be c:\dir0 also, right?
my understanding is that 1) and 2) are the same.
includeh10
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You know how you make an installer by packing a file under a
file then a footer under that.
When you use the file it uses the top file, so you make the top file read the footer to get the file sizes, read them into a buffer and write them out...
Well i was planing on using that same method to pack things like programs that are just dialogs under it, and have my program, (rather than write it to a file, and erase it afterwords, just execute it out of memory)... I could just make child windows, but this seems easyer to me, and i'm also mainly curious if it is really possile to do this...
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Jabish wrote:
...rather than write it to a file, and erase it afterwords, just execute it out of memory...
This question has been asked several times in the past. Search CP for "PE file format."
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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You cannot run a file "from memory" because processes have separate address spaces. How would the new process read its code from yours?
Also, the OS uses memory-mapped files to load a binary into memory, which requires that the binary be a disk file.
--Mike--
Visual C++ MVP 
LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ
Strange things are afoot at the U+004B U+20DD
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Can't you use malloc and get a chunk of memory big enough to hold the binary program, then manually load it from disk to memory? Next, use _beginthread/_beginthreadex and point it to the start of the memory you allocated? I know this probably isn't all you need to do, but that's what I'm thinking in a broadstroke. This wouldn't be it's own process either, it'll be a thread running under the guys process too.
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Thank (all of you)... Just got back on so sorry i diddn't thank all of you earler.
Just wondering about the "PE file format" is it that PE projector thing?
also do I have to use any special way of reading the file to a buffer, or can I do it the way I always do:
<br />
FILE *in;<br />
<br />
long size;<br />
char *Buffer;<br />
<br />
if(in = fopen("[blah]", "rb"))<br />
{<br />
fseek(in, 0, SEEK_END);<br />
size = ftell(in);<br />
Buffer = (char *) malloc(size);<br />
fseek(in, 0, SEEK_SET);<br />
<br />
fread(Buffer, 1, size, in);<br />
<br />
fclose(in);<br />
}<br />
----------
and then do the PE thing, or do i need to use ReadFile() or something...
If possible a specific code example would be appreicated, (haven't tried anything like this before) just a little confused.
PS:
wasn't planning on using this idea for a child window type deal... I was thinking more on the line of something like:
a patcher like there is before you log on to a game, after the patcher got it's files it could unpack and execute parts of the game, or the game could just unpack the patcher... that kind of thing. I don't actually NEED this, am just curious about it. Thanks again =8^)... please don't steal face... 
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Jabish wrote:
Just wondering about the "PE file format" is it that PE projector thing
The example that I have seen, and may still have on my disk at work, requires knowledge of the Portable Executable file format.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Hi everybody, i am using a simple thread in my program,
when i launch the thread it works , but slows my machine,
in the task manager the CPU usage is 100% until the thread is ended. I am using simple AfxBEginThread(..) function ,is there any other way to make thread work , without slowing down my PC???
With Best Regards
m0n0
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The mere existence of a secondary thread will not cause the CPU usage to jump to 100%. You are doing something in this thread to cause that. Without seeing your code, it's impossible to say.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Well... The AfxBeginThread function will simple create a thread to do work on the controller function you specify. So the CPU usage is down to what's in the function you write. If you write a function which crunches numbers in a loop or whatver, then your CPU usage will go to 100% while the function keeps crunching. However, if you only need to run a calculation intermittently try using Sleep(100), or CEvents to put the thread into suspended animation giving the rest of the threads time to do their jobs.
What are you trying to do with your worker thread?
Joel Holdsworth
Wanna give me a job this summer?
Check out my online CV and project history[^]
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"What are you trying to do with your worker thread?"
Pretty Lot, i am testing huge numbers(100 or more digits )
on primality.
Actually i am doing lots of operations there,probably this makes my cpu go 100% , anyway thanks for attention to all 
m0n0
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Change your priority to THREAD_PRIORITY_IDLE instead of the default which is normal. That'll lower the thread priority so it won't take your system with it. The command would be:
CWinThread * threadptr = AfxBeginThread(
pfnThreadProc,
pParam,
THREAD_PRIORITY_IDLE,
0,
0,
NULL
);
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I have written an xll with basic arithmetical calculations. I want to use the debugger to step through those functions to confirm they are working properly. I have tried to do this by setting Excel as the Command application and a spreadsheet that loads the xll as the Command argument. I then place breakpoints throughout the functions. Unfortunately, the VC++.Net debugger never recognises the breakpoints (the warning glyph ? breakpoint appears). The two error messages are firstly:
"Excel.exe does not contain debugging information. (No symbols loaded.) Click OK to debug anyway"
Secondly:
"The following breakpoint cannot be set: When 'double' changes
Data breakpoints are not supported in the Common Language Runtime"
Is the only way to debug an xll/dll to create a separate basic application to call the xll function? Ideally I would want to be able to call from Excel so that I know exactly what Excel is feeding to the xll function parameters. Any thoughts you may have would be appreciated.
Regards
Jeremy
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Could anyone describe me how the process creates threads? I learned that there always exists a primary thread created as soon as the process gets started, but from then, how can we know how many threads are created? and when? and how can we know? can we take control of them?(I don't mention the threads created manually by me on using CreateThread, AfxBeginThread)
Regards.
Grenouille
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well, if you call once AfxBeginThread(), i believe you have only one thread...
TOXCCT >>> GEII power
[toxcct][VisualCalc]
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A process can identify all of the threads that it owns by using the Thread32First()/Thread32Next() pair.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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What that complicated?
Just create a Dll file, attach it to the process and the DllMain function will get every time a new thread is created or terminated!
Read about DllMain in MSDN.
Don't try it, just do it! 
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Alexander M. wrote:
What that complicated?
What's so complicated about using Thread32First()? It's very easy to use and only requires a few lines of code. Creating a separate DLL for this task is more along the lines of overkill.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Hello to all of you.
If anyone knows I would ge glad if someone could help me on this:
I have a form where there is a panel (call it panel_1). In this panel I want to display 5-6 panels, one at a time, depending on some buttons. Here is what I do. In visual studio .net, I create a new userControl class where I place my panel (panel_2). Then, i go to my main form, where panel_1 is and I add my userControl. But the buttons of panel_2 are BLACK, and it seems that there is no refreshing.
When I run the application, the part of the screen that has panel_2 shows abnormal things such as icons of my desktop!
Is there any bug, when adding userControls. Do i need to do anything, such as repaint or something else?
Thank you in advance!
Kostas Stamatis
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hi there !
i got a crucial problem with my singleton class. maybe there's anybody who could help me out
i implemented a singleton framework as a static lib that handles callbacks, triggers methods etc.. next to this lib, i got several dlls that access this lib.
the problem basically is that every dll allocates its own memory and includes a copy of the lib there. so, from outside (let's say, the testing app), there's not one framework, but several according to the amount of dlls that load the framework.
as there must be only one framework, i'm looking for kind of a workaround to get rid of this "feature".
i've already tried to build the singleton as a dll which then just would be linked to the other dlls, but that didn't show any positive effect either.
so in other words, is there any memory segment (which would be the heap of the current context/process) that is used by all libraries (be it static or dynamic) that i could store at least the singleton pointer in ?
a really quick solution would be to instantiate this pointer at the testing app or create a shared memory object, but these kinds of solution don't satisfy me at all.
as i'm in an absolute rush, pls come back to me as soon as possible. thank you all very much for any hint or opinion.
best regards,
j
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Singleton 'pointer' ? This does not make any sense to me. You can't readily create a pointer to some memory segment that is the same address among all processes.
The address returned by any regular 'malloc' or 'new' calls is not guaranteed to be at the same address in all processes anyway. You can try to FORCE it using some combination of VirtualAlloc and memory mapped file calls, but you always, and I mean ALWAYS, run the risk that some DLL will load at that address anyway. So then by the time your app is running its main loop, you will not be able to allocoate memory at that address anyway.
If you want something 'shared' by all processes, your best bet is to create a memory mapped file and map to it from each process. Put your 'pointer independent' code in that shared memory.
If you want a fixed-size chunk of memory that is shared by all processes that is 'owned' by a DLL, then you can put some variables or data structures into a shared data segment.
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