C / C++ / MFC Discussion Boards

Member 432083115-Jul-09 22:12

Member 4320831

15-Jul-09 22:12

Hi, I'm rather new to using COM. I was to trying to connect to WMI and plan to create two separate threads that will connect to WMI parallelly. Both the threads will be watching for some WMI events. My question is, do I need to use two separate proxies for each of the threads. Can I use the same IWbemServices pointer (say declared globally ,or passed by reference to the thread) in my second thread as well. This other thread would be looking for some other event but using the same WMI namespace. Would that work?

Also can the same WMI locator (obtained from CoCreateInstance) be used to connect to other WMI namespaces as well?

I'm very new to COM and don't understand the concepts too well. Please help Confused | :confused:

[Edit]
Someone please guide me a little here! I'm totally lost in COM ocean.. Cry | :((

modified on Thursday, July 16, 2009 11:37 AM

Re: Connecting to WMI -using COM

Stuart Dootson15-Jul-09 22:24

Stuart Dootson

15-Jul-09 22:24

I think it depends how you initialise COM. COM can be run as single[^]- or multi[^]-threaded. I think the multi-threaded version would allow you to share interface pointers.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: Connecting to WMI -using COM

Member 432083116-Jul-09 1:59

Member 4320831

16-Jul-09 1:59

Well I've initialized it as COINIT_MULTITHREADED in CoInitializeEx() but it doesn't work as hoped. I use the same IWbemServices pointer (all initializations done just the first time) to run an ExecNotificationQuery with different WMI queries. However my ExecNotificationQuery fails. The two queries work fine if done individually but I can't seem to be able register for two separate WMI events separately.

If I do the whole initialization again for my 2nd query then I get an error in COM security initialization.

Code Snippet:
HANDLE hres;
hres = CoInitializeEx(0, COINIT_MULTITHREADED);
if (FAILED(hres))
{output something}
hres = CoInitializeSecurity(NULL,1,NULL,NULL, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE,NULL, EOAC_NONE,NULL);
hres = CoCreateInstance(
CLSID_WbemLocator,
0,
CLSCTX_INPROC_SERVER,
IID_IWbemLocator, (LPVOID *) &pLoc);
hres = pLoc->ConnectServer(
_bstr_t(L"ROOT\\WMI"), // Object path of WMI namespace
NULL, // User name. NULL = current user
NULL, // User password. NULL = current
0, // Locale. NULL indicates current
NULL, // Security flags.
0, // Authority (e.g. Kerberos)
0, // Context object
&pSvc // pointer to IWbemServices proxy
);
hres = CoSetProxyBlanket(
pSvc, // Indicates the proxy to set
RPC_C_AUTHN_WINNT, // RPC_C_AUTHN_xxx
RPC_C_AUTHZ_NONE, // RPC_C_AUTHZ_xxx
NULL, // Server principal name
RPC_C_AUTHN_LEVEL_CALL, // RPC_C_AUTHN_LEVEL_xxx
RPC_C_IMP_LEVEL_IMPERSONATE, // RPC_C_IMP_LEVEL_xxx
NULL, // client identity
EOAC_NONE // proxy capabilities
);

IEnumWbemClassObject* pEnumerator = NULL;
hres = pSvc->ExecNotificationQuery(
bstr_t("WQL"),
bstr_t("SELECT * FROM ..."),
WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
NULL,
&pEnumerator);
Then I use pEnumerator->Next within a loop and cleanup.

I run this function twice in separate threads.Ideas?

IP from socket handle

sunny_vc15-Jul-09 21:17

sunny_vc

15-Jul-09 21:17

Hi all,
Is it possible to get client IP from the socket handle to which it is connected.
If possible please let me know.

Regards,
Sunil Kumar

Re: IP from socket handle

CPallini15-Jul-09 21:28

CPallini

15-Jul-09 21:28

getpeername [^] looks promising.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

CreateProcess doesn’t passes command line arguments [modified]

staticv15-Jul-09 20:56

staticv

15-Jul-09 20:56

Hello I have the following code but it isn't working as expected, can't figure out what the problem is.

Basically, I'm executing a process (a .NET process) and passing it command line arguments, it is executed successfully by CreateProcess() but CreateProcess() isn't passing the command line arguments

What am I doing wrong here??

int main(int argc, char* argv[])
{
    PROCESS_INFORMATION ProcessInfo; //This is what we get as an [out] parameter

    STARTUPINFO StartupInfo; //This is an [in] parameter

    ZeroMemory(&StartupInfo, sizeof(StartupInfo));
    StartupInfo.cb = sizeof StartupInfo ; //Only compulsory field

    LPTSTR cmdArgs = "name@example.com";

    if(CreateProcess("D:\\email\\smtp.exe", cmdArgs, 
        NULL,NULL,FALSE,0,NULL,
        NULL,&StartupInfo,&ProcessInfo))
    { 
        WaitForSingleObject(ProcessInfo.hProcess,INFINITE);
        CloseHandle(ProcessInfo.hThread);
        CloseHandle(ProcessInfo.hProcess);

        printf("Yohoo!");
    }  
    else
    {
        printf("The process could not be started...");
    }

    return 0;
}

Hey one more thing, if I pass my cmdArgs like this:

// a space as the first character
LPTSTR cmdArgs = " manzoor10@gmail.com";

I get the error:

Object reference not set to an instance of an object

then CreateProcess returns TRUE but my target process isn't executed.

Top Web Hosting Providers[^]

Do, or do not. There is no 'try'.

modified on Thursday, June 10, 2010 2:13 AM

Re: CreateProcess doesn’t passes command line arguments

Franck Paquier15-Jul-09 21:18

Franck Paquier

15-Jul-09 21:18

good morning

Not sure it will solve your problem but did you notice that lpCommandLine is an in out parameter ?
in MSDN Help i found the following information:

The Unicode version of this function, CreateProcessW, can modify the contents of this string. Therefore, this parameter cannot be a pointer to read-only memory (such as a const variable or a literal string). If this parameter is a constant string, the function may cause an access violation.

Hope this will help.
Regards
Franck

Re: CreateProcess doesn’t passes command line arguments

Michael Schubert15-Jul-09 22:17

Michael Schubert

15-Jul-09 22:17

This:
http://bobmoore.mvps.org/Win32/w32tip46.htm[^]
may give you some insight but I'm not sure.

I always use CreateProcess by concatenating the app name and the arguments and set this as the second parameter (first parameter set to NULL) and it has never failed.

Re: CreateProcess doesn’t passes command line arguments

Stuart Dootson15-Jul-09 22:20

Stuart Dootson

15-Jul-09 22:20

I suspect your command-line argument is being interpreted as the executable name. See the CreateProcess[^] documentation:

Console processes written in C can use the argc and argv arguments to parse the command line. Because argv[0] is the module name, C programmers generally repeat the module name as the first token in the command line.

While that's talking about C programs, .NET programs conform to that as well. Add an argument before the e-mail address and you should find it all works.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Re: CreateProcess doesn’t passes command line arguments

tns_ranjith15-Jul-09 22:41

tns_ranjith

15-Jul-09 22:41

PROCESS_INFORMATION pi;
ZeroMemory (&pi, sizeof (pi));

STARTUPINFOA si;
ZeroMemory( &si, sizeof(si) );
si.cb = sizeof(si);
si.dwFlags = STARTF_USESHOWWINDOW;
//si.wShowWindow = SW_HIDE;
si.wShowWindow = SW_SHOW;

CreateProcessA (NULL, cmd, 0, 0, 0, CREATE_NO_WINDOW, 0, 0, &si, &pi);

Re: CreateProcess doesn’t passes command line arguments

Michael Schubert15-Jul-09 23:00

Michael Schubert

15-Jul-09 23:00

tns_ranjith wrote:
STARTUPINFOA

tns_ranjith wrote:
CreateProcessA

Why?

Re: CreateProcess doesn’t passes command line arguments

Rajesh R Subramanian15-Jul-09 23:45

Rajesh R Subramanian

15-Jul-09 23:45

You shouldn't be giving him any importance (take a look at some of his recent posts). You could just mark it down instead.

It is a crappy thing, but it's life -^ Carlo Pallini

Re: CreateProcess doesn’t passes command line arguments

Michael Schubert15-Jul-09 23:48

Michael Schubert

15-Jul-09 23:48

Oh, I thought he was trying to make a point.

Re: CreateProcess doesn’t passes command line arguments

tns_ranjith16-Jul-09 0:11

tns_ranjith

16-Jul-09 0:11

for unicode project u want to use non unicode characters support..

How to test is the given path is a directory or a file?

Chesnokov Yuriy15-Jul-09 20:56

Chesnokov Yuriy

15-Jul-09 20:56

In C run-time libs is there a function that renurns if the given string is a directory or a file name?

Чесноков

Re: How to test is the given path is a directory or a file?

Randor 15-Jul-09 21:08

Randor

15-Jul-09 21:08

_stat, _wstat Functions[^]

Best Wishes,
-David Delaune

Re: How to test is the given path is a directory or a file?

Chesnokov Yuriy15-Jul-09 22:50

Chesnokov Yuriy

15-Jul-09 22:50

Thank you very much, your solution is the right one for C run-times.

Чесноков

Re: How to test is the given path is a directory or a file? [modified]

CPallini15-Jul-09 21:21

CPallini

15-Jul-09 21:21

~~Nope~~. However, you may find these functions [^] useful.
Smile | :)

[added]
I was wrong, see [^]
[/added]

modified on Thursday, July 16, 2009 3:43 AM

Re: How to test is the given path is a directory or a file?

Randor 15-Jul-09 21:38

Randor

15-Jul-09 21:38

CPallini wrote:
Nope.

Hi Carlos,
Are you sure about that? Smile | :)

Best Wishes,
-David Delaune

Re: How to test is the given path is a directory or a file?

CPallini15-Jul-09 21:43

CPallini

15-Jul-09 21:43

Randor wrote:
Hi Carlos,
Are you sure about that?

I'm quite sure of the opposite, now. Blush | :O

I've to admit, I erroneously read 'path' as 'name' (i.e. more caffeine is needed this morning)
Big Grin | :-D

Re: How to test is the given path is a directory or a file?

Michael Schubert15-Jul-09 23:13

Michael Schubert

15-Jul-09 23:13

Randor wrote:
Carlos

It's Carlo.

Carlos is the guy who likes tapas and slaughters bulls for a living.

Re: How to test is the given path is a directory or a file?

Michael Schubert15-Jul-09 22:29

Michael Schubert

15-Jul-09 22:29

If you can use Win32, GetFileAttributes() will do that for you nicely:

http://msdn.microsoft.com/en-us/library/aa364944%28VS.85%29.aspx[^]

Help in writing a program?

jon ray15-Jul-09 20:50

jon ray

15-Jul-09 20:50

is it possible to prevent the user from left clicking on USB drive icon but allow to right clicking?

i would appreciate if some one post an example for it

Re: Help in writing a program?

David Crow16-Jul-09 2:52

David Crow

16-Jul-09 2:52

jon ray wrote:
is it possible to prevent the user from left clicking on USB drive icon...

Within Windows Explorer?

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Re: Help in writing a program?

jon ray24-Jul-09 18:45

jon ray

24-Jul-09 18:45

sorry for the late reply i was very busy until yesterday and yes within windows explorer

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.