How to retrive process handle by using application name in c++? - c++

Question

How to retrieve process handle by using application name in c++?
Is there any windows API is there?
Example: Sample.exe
I have to get the handle of this sample.exe and I need to call Terminate process on that handle.
Any one suggest a good solution for this.
Note: its should support winxp and win8
Thanks in Advance

Answer 1

You should use toolhelp API's:
HANDLE OpenProcessByName(LPCTSTR Name, DWORD dwAccess)
{
HANDLE hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if (hSnap != INVALID_HANDLE_VALUE)
{
PROCESSENTRY32 pe;
ZeroMemory(&pe, sizeof(PROCESSENTRY32));
pe.dwSize = sizeof(PROCESSENTRY32);
Process32First(hSnap, &pe);
do
{
if (!lstrcmpi(pe.szExeFile, Name))
{
return OpenProcess(dwAccess, 0, pe.th32ProcessID);
}
} while (Process32Next(hSnap, &pe));
}
return INVALID_HANDLE_VALUE;
}
For example:
#include <windows.h>
#include <tlhelp32.h>
//...
int main()
{
HANDLE hFire = OpenProcessByName("firefox.exe", PROCESS_VM_READ);
cout << "Handle: " << hFire << endl;
CloseHandle(hFire);
cin.get();
return 0;
}
But you should be careful because if there are more than 1 copy of process you will get a handle of the first. To handle all processes in "return OpenProcess" use call of some function like Handler(OpenProcess(dwAccess, 0, pe.th32ProcessID)):
void Handler(HANDLE hndl)
{
//... work with your Handle
CloseHandle(hndl);
}
//...
if (!lstrcmpi(pe.szExeFile, Name))
{
Handler(OpenProcess(dwAccess, 0, pe.th32ProcessID)):
}
//...

Answer 2

To fetch the process name from process id see quiestions: get process name from process id (win32) or How to get the process name in C++
Enumerate process documentation https://msdn.microsoft.com/en-us/library/windows/desktop/ms682629%28v=vs.85%29.aspx Example code: https://msdn.microsoft.com/ru-ru/library/windows/desktop/ms682623%28v=vs.85%29.aspx
EDIT: There is solution that does not have problem "return the hanlde of the first matching found, whereas there may be multiple instances". This solution return array of pairs ProcessId and names, and you can select that you need in simple loop.
#include <windows.h>
#include <tlhelp32.h>
#include <iostream>
#include <utility>
#include <vector>
#include <string>
#include <map>
typedef std::pair<DWORD,std::string> ProcessVectorEntry;
typedef std::vector<ProcessVectorEntry> ProcessVector;
void getProcessInformation( ProcessVector& processVector ) {
HANDLE hSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if(hSnapshot) {
PROCESSENTRY32 pe32;
pe32.dwSize = sizeof(PROCESSENTRY32);
if(Process32First(hSnapshot, &pe32)) {
do {
processVector.push_back( ProcessVectorEntry( pe32.th32ProcessID, pe32.szExeFile ) );
} while(Process32Next(hSnapshot, &pe32));
}
CloseHandle(hSnapshot);
}
}
And simple search in main
int main() {
std::string search = "firefox.exe";
ProcessVector processVector;
getProcessInformation( processVector );
std::cout << "Process IDs contains " << search << " in name:" << std::endl;
for( int i=0; i<processVector.size(); ++i )
if( processVector[i].second.find(search) != std::string::npos )
std::cout << processVector[i].first << std::endl;
return 0;
}