Programming Forums > Application Development > C++

badbasser98 · Feb 22nd, 2006, 12:23 PM

I am looking to modify a program that I finished some time ago. It searches for and deletes place holder files for a terminal emulator. Although for it to work properly, all open terminal windows need to be closed. As of right now the end user is being prompted by a message box to make sure they close any open windows before continuing. I was wondering if there is a way to have the program look when it is first started to see if there are any open before allowing the rest of the program to run. I would like it to detect the windows, prompt the user about them, and close the windows if the user clicks Continue, or let them do it manually and close my program if they click cancel. If so, what functions/methods should I be researching to do this?

Any help is greatly appreciated

-BB98

**Edit: Guess I should include that this is for a Windows based system.

Cache · Feb 22nd, 2006, 1:19 PM

You might find these links useful:

Enumerating all processes:
http://msdn.microsoft.com/library/de..._processes.asp

TerminateProcess function:
http://msdn.microsoft.com/library/de...ateprocess.asp

badbasser98 · Feb 22nd, 2006, 3:26 PM

guess I am jumping into the deep end on this one... When it is talking about the processID, would that be the same as its displayed name in the TaskManager Process List? I guess I am quite confused as to how to get the handle of the process.:o Also, for each emulator window that is open, it adds another entry to the Running Process List with identical names. So if there are 4 windows open, there are four identical listings in the process list. Does this complicate things?

Thanks for the help thus far.
-BB98

Cache · Feb 22nd, 2006, 8:34 PM

What you call the "displayed name" is the image name, and can be the same for multiple instances of the same executable. The PID, however, is unique to each instance. You could get the PID of any process that has the image name you are looking for, and take it from there.

The example in the link I gave shows how to get a handle to a process.

Dameon · Feb 22nd, 2006, 9:00 PM

There's a heck of a difference between enumerating windows and enumerating processes as well as between terminating processes and closing windows. MSDN has a wealth of info on the API calls needed. Sending a close message to the windows you want to close is much more graceful. Terminating the process is like the "End Process" button in the task manager you mentioned. Sending a close message is like clicking the X in the control box or pressing Alt+F4

badbasser98 · Feb 23rd, 2006, 9:55 AM

This is the sample code off of MSDN for Enumerating all processes... Would someone mind explaining where in the code the ProcessID is being obtained, or does it show this?

(Toggle Plain Text)

 #include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include "psapi.h"
 
void PrintProcessNameAndID( DWORD processID )
{
	TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>");
 
	// Get a handle to the process.
 
	HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
								 PROCESS_VM_READ,
								 FALSE, processID );
 
	// Get the process name.
 
	if (NULL != hProcess )
	{
		HMODULE hMod;
		DWORD cbNeeded;
 
		if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod), 
			 &cbNeeded) )
		{
			GetModuleBaseName( hProcess, hMod, szProcessName, 
							 sizeof(szProcessName)/sizeof(TCHAR) );
		}
	}
 
	// Print the process name and identifier.
 
	_tprintf( TEXT("%s (PID: %u)\n"), szProcessName, processID );
 
	CloseHandle( hProcess );
}
 
void main( )
{
	// Get the list of process identifiers.
 
	DWORD aProcesses[1024], cbNeeded, cProcesses;
	unsigned int i;
 
	if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) )
		return;
 
	// Calculate how many process identifiers were returned.
 
	cProcesses = cbNeeded / sizeof(DWORD);
 
	// Print the name and process identifier for each process.
 
	for ( i = 0; i < cProcesses; i++ )
		PrintProcessNameAndID( aProcesses[i] );
}

Thanks for the info

nnxion · Feb 23rd, 2006, 12:34 PM

Is this really not clear?

(Toggle Plain Text)

void PrintProcessNameAndID( DWORD processID )

and

(Toggle Plain Text)

PrintProcessNameAndID( aProcesses[i] );

What then do you think the processID is?

badbasser98 · Feb 24th, 2006, 8:49 AM

OK, I understand it now. Although I cannot get the code to compile, is there a piece of syntax missing? This is the error I am getting.

Quote:

Originally Posted by Dev-C++ 4.9.9.2

[LINKER ERROR] unidentified reference to 'EnumProcessModules@16'
[LINKER ERROR] unidentified reference to 'GetModuleBaseNameA@16'
[LINKER ERROR] unidentified reference to 'EnumProcesses@12'
Id returned 1 exit status

These are new expressions to me and I am flying blind trying to get them to work.

Is there a DLL or other file that must be included?
Thanks,
-BB98

DaWei · Feb 24th, 2006, 9:09 AM

Check the documentation for libraries required, acquire them if you don't have them, and add them to the path the linker searches or to the command line or to the makefile (depending on how you are building the program).

nnxion · Feb 24th, 2006, 9:35 AM

You have to link to Psapi.lib, I'm not sure what that is named in Dev-C++.

Feb 22nd, 2006, 12:23 PM	#1
badbasser98 Hobbyist Programmer Join Date: Mar 2005 Location: United States Posts: 124 Rep Power: 4	Search for and close open windows I am looking to modify a program that I finished some time ago. It searches for and deletes place holder files for a terminal emulator. Although for it to work properly, all open terminal windows need to be closed. As of right now the end user is being prompted by a message box to make sure they close any open windows before continuing. I was wondering if there is a way to have the program look when it is first started to see if there are any open before allowing the rest of the program to run. I would like it to detect the windows, prompt the user about them, and close the windows if the user clicks Continue, or let them do it manually and close my program if they click cancel. If so, what functions/methods should I be researching to do this? Any help is greatly appreciated -BB98 **Edit: Guess I should include that this is for a Windows based system. __________________ Learning to use C++ and loving every minute of it.

Feb 22nd, 2006, 3:26 PM	#3
badbasser98 Hobbyist Programmer Join Date: Mar 2005 Location: United States Posts: 124 Rep Power: 4	guess I am jumping into the deep end on this one... When it is talking about the processID, would that be the same as its displayed name in the TaskManager Process List? I guess I am quite confused as to how to get the handle of the process.:o Also, for each emulator window that is open, it adds another entry to the Running Process List with identical names. So if there are 4 windows open, there are four identical listings in the process list. Does this complicate things? Thanks for the help thus far. -BB98 __________________ Learning to use C++ and loving every minute of it.

Feb 22nd, 2006, 9:00 PM	#5
Dameon Troll Join Date: Apr 2005 Location: Texas Posts: 732 Rep Power: 4	There's a heck of a difference between enumerating windows and enumerating processes as well as between terminating processes and closing windows. MSDN has a wealth of info on the API calls needed. Sending a close message to the windows you want to close is much more graceful. Terminating the process is like the "End Process" button in the task manager you mentioned. Sending a close message is like clicking the X in the control box or pressing Alt+F4 __________________ MD5(sig) = bcef75433db02e9ad9bf81d6f7c5c270

Feb 23rd, 2006, 9:55 AM	#6
badbasser98 Hobbyist Programmer Join Date: Mar 2005 Location: United States Posts: 124 Rep Power: 4	This is the sample code off of MSDN for Enumerating all processes... Would someone mind explaining where in the code the ProcessID is being obtained, or does it show this? (Toggle Plain Text) #include <windows.h> #include <stdio.h> #include <tchar.h> #include "psapi.h" void PrintProcessNameAndID( DWORD processID ) { TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>"); // Get a handle to the process. HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION \| PROCESS_VM_READ, FALSE, processID ); // Get the process name. if (NULL != hProcess ) { HMODULE hMod; DWORD cbNeeded; if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod), &cbNeeded) ) { GetModuleBaseName( hProcess, hMod, szProcessName, sizeof(szProcessName)/sizeof(TCHAR) ); } } // Print the process name and identifier. _tprintf( TEXT("%s (PID: %u)\n"), szProcessName, processID ); CloseHandle( hProcess ); } void main( ) { // Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses; unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the name and process identifier for each process. for ( i = 0; i < cProcesses; i++ ) PrintProcessNameAndID( aProcesses[i] ); } #include <windows.h> #include <stdio.h> #include <tchar.h> #include "psapi.h" void PrintProcessNameAndID( DWORD processID ) { TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>"); // Get a handle to the process. HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION \| PROCESS_VM_READ, FALSE, processID ); // Get the process name. if (NULL != hProcess ) { HMODULE hMod; DWORD cbNeeded; if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod), &cbNeeded) ) { GetModuleBaseName( hProcess, hMod, szProcessName, sizeof(szProcessName)/sizeof(TCHAR) ); } } // Print the process name and identifier. _tprintf( TEXT("%s (PID: %u)\n"), szProcessName, processID ); CloseHandle( hProcess ); } void main( ) { // Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses; unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the name and process identifier for each process. for ( i = 0; i < cProcesses; i++ ) PrintProcessNameAndID( aProcesses[i] ); } Thanks for the info __________________ Learning to use C++ and loving every minute of it.

Feb 23rd, 2006, 12:34 PM	#7
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	Is this really not clear? (Toggle Plain Text) void PrintProcessNameAndID( DWORD processID ) void PrintProcessNameAndID( DWORD processID ) and (Toggle Plain Text) PrintProcessNameAndID( aProcesses[i] ); PrintProcessNameAndID( aProcesses[i] ); What then do you think the processID is? __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

Feb 22nd, 2006, 1:19 PM	#2
Cache Hobbyist Join Date: Sep 2005 Posts: 261 Rep Power: 3	You might find these links useful: Enumerating all processes: http://msdn.microsoft.com/library/de..._processes.asp TerminateProcess function: http://msdn.microsoft.com/library/de...ateprocess.asp

Feb 22nd, 2006, 8:34 PM	#4
Cache Hobbyist Join Date: Sep 2005 Posts: 261 Rep Power: 3	What you call the "displayed name" is the image name, and can be the same for multiple instances of the same executable. The PID, however, is unique to each instance. You could get the PID of any process that has the image name you are looking for, and take it from there. The example in the link I gave shows how to get a handle to a process.

Feb 24th, 2006, 9:09 AM	#9
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Check the documentation for libraries required, acquire them if you don't have them, and add them to the path the linker searches or to the command line or to the makefile (depending on how you are building the program). __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Feb 24th, 2006, 9:35 AM	#10
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	You have to link to Psapi.lib, I'm not sure what that is named in Dev-C++. __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

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Programming Forums > Application Development > C++

Search for and close open windows