Thread: Easiest what to get a windows handle with just the filename?

is there an easy way to get the main windows handle(it only uses one), by just knowing the programs filename?

Weird request...!!!

I had a few tries at this, and it appears there would be more than 1 way to do this.....
GetWindowModuleFileName() looked like a winner, but for some reason I couldnt get it to do what I wanted.....Also I realised my old version of the SDK is starting to become a pain in the arse......but that's another story....

Anyway...not perfect by a long shot, but it seems to produce something....

Code:

#include <windows.h>
#include <iostream>
#include <cstring>
using namespace std;

typedef DWORD (WINAPI *GMFNE)(HANDLE,HMODULE,LPSTR,DWORD);
/*My PSAPI lib seems to be faulty......so I had to 
link to GetModuleFileNameEx at runtime*/

char exefile[] = "C:\\WINNT\\System32\\calc.exe";
//The exe of your choice....


BOOL CALLBACK EnumWindowsProc(HWND hwnd,LPARAM lParam){

	GMFNE lpGMFNE = (GMFNE)lParam;
	/*Entry point to the GetModuleFileNameEx func*/
	DWORD dwPID,//Process ID
		  dwBytes;//Bytes returned
	HANDLE hProc;//Process Handle
	HMODULE hMod;//Module Handle
	char buff[MAX_PATH];//Buffer

	hMod = (HMODULE)GetWindowLong(hwnd,GWL_HINSTANCE);
	//Get the module for the window
	
	GetWindowThreadProcessId(hwnd,&dwPID);
	//Also the Process ID

	hProc = OpenProcess(PROCESS_ALL_ACCESS,FALSE,dwPID);
	//Now use that ID to get Process handle
	
	
	if(hProc && hMod){
		dwBytes = lpGMFNE(hProc,hMod,buff,MAX_PATH);
		//GetModuleFileNameEx
		if(dwBytes){
			buff[dwBytes] = NULL;
			if(!strcmp(exefile,buff))//Is it from calc.exe?
				cout << "Found HWND - " << hwnd << endl;
			}

		CloseHandle(hProc);//Close
	}

	return TRUE;
}



int main(void){

	HMODULE hMod;
	GMFNE lpGMFNE;
	

	hMod = LoadLibrary("PSAPI.dll");
	

	if(!hMod){
		cout << "PSAPI.dll not present";
		return 1;
	}

	lpGMFNE = (GMFNE)GetProcAddress(hMod,"GetModuleFileNameExA");
	if(!lpGMFNE){
		cout << "Could not locate procedure";
		FreeLibrary(hMod);
		return 1;
	}

	EnumWindows((WNDENUMPROC)EnumWindowsProc,(LPARAM)lpGMFNE);

	FreeLibrary(hMod);

	return 0;
}

This uses the PSAPI.dll which is an addon to WINNT (oh...you need NT at least for this prog as it deals with processes and stuff - there's a shock! )...this dll is usually in the system32 dir as loads of apps ship it & install it.....

The code is messy, and there is probably a better way, but it might do with some tidying up.