CODEWITHSUNDEEP
c++winapiprocess
Malfist
Malfist

Reputation: 31815

How can I get a process handle by its name in C++?

I'm trying to get the process handle of, say example.exe, so I can call TerminateProcess on it. How can I do this? Notice, it doesn't have a window so FindWindow won't work.

Upvotes: 74

Views: 208625

Answers (7)

xian
xian

Reputation: 4703

#include <cstdio>
#include <windows.h>
#include <tlhelp32.h>

int main( int, char *[] )
{
    PROCESSENTRY32 entry;
    entry.dwSize = sizeof(PROCESSENTRY32);

    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

    if (Process32First(snapshot, &entry) == TRUE)
    {
        while (Process32Next(snapshot, &entry) == TRUE)
        {
            if (stricmp(entry.szExeFile, "target.exe") == 0)
            {  
                HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, entry.th32ProcessID);

                // Do stuff..

                CloseHandle(hProcess);
            }
        }
    }

    CloseHandle(snapshot);

    return 0;
}

Also, if you'd like to use PROCESS_ALL_ACCESS in OpenProcess, you could try this:

#include <cstdio>
#include <windows.h>
#include <tlhelp32.h>

void EnableDebugPriv()
{
    HANDLE hToken;
    LUID luid;
    TOKEN_PRIVILEGES tkp;

    OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &hToken);

    LookupPrivilegeValue(NULL, SE_DEBUG_NAME, &luid);

    tkp.PrivilegeCount = 1;
    tkp.Privileges[0].Luid = luid;
    tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

    AdjustTokenPrivileges(hToken, false, &tkp, sizeof(tkp), NULL, NULL);

    CloseHandle(hToken); 
}

int main( int, char *[] )
{
    EnableDebugPriv();

    PROCESSENTRY32 entry;
    entry.dwSize = sizeof(PROCESSENTRY32);

    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);

    if (Process32First(snapshot, &entry) == TRUE)
    {
        while (Process32Next(snapshot, &entry) == TRUE)
        {
            if (stricmp(entry.szExeFile, "target.exe") == 0)
            {  
                HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, entry.th32ProcessID);

                // Do stuff..

                CloseHandle(hProcess);
            }
        }
    }

    CloseHandle(snapshot);

    return 0;
}

Upvotes: 97

user13690398
user13690398

Reputation:

If you don't mind using system(), doing system("taskkill /f /im process.exe") would be significantly easier than these other methods.

Upvotes: 2

BullyWiiPlaza
BullyWiiPlaza

Reputation: 19243

The following code can be used:

DWORD FindProcessId(const std::wstring& processName)
{
    PROCESSENTRY32 processInfo;
    processInfo.dwSize = sizeof(processInfo);

    HANDLE processesSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
    if (processesSnapshot == INVALID_HANDLE_VALUE) {
        return 0;
    }

    Process32First(processesSnapshot, &processInfo);
    if (!processName.compare(processInfo.szExeFile))
    {
        CloseHandle(processesSnapshot);
        return processInfo.th32ProcessID;
    }

    while (Process32Next(processesSnapshot, &processInfo))
    {
        if (!processName.compare(processInfo.szExeFile))
        {
            CloseHandle(processesSnapshot);
            return processInfo.th32ProcessID;
        }
    }

    CloseHandle(processesSnapshot);
    return 0;
}

Usage:

auto processId = FindProcessId(L"blabla.exe");

Getting a handle should be obvious, just call OpenProcess() or similar on it.

Upvotes: 4

Michael
Michael

Reputation: 55445

The following code shows how you can use toolhelp and OpenProcess to get a handle to the process. Error handling removed for brevity.

HANDLE GetProcessByName(PCSTR name)
{
    DWORD pid = 0;

    // Create toolhelp snapshot.
    HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
    PROCESSENTRY32 process;
    ZeroMemory(&process, sizeof(process));
    process.dwSize = sizeof(process);

    // Walkthrough all processes.
    if (Process32First(snapshot, &process))
    {
        do
        {
            // Compare process.szExeFile based on format of name, i.e., trim file path
            // trim .exe if necessary, etc.
            if (string(process.szExeFile) == string(name))
            {
               pid = process.th32ProcessID;
               break;
            }
        } while (Process32Next(snapshot, &process));
    }

    CloseHandle(snapshot);

    if (pid != 0)
    {
         return OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);
    }

    // Not found


       return NULL;
}

Upvotes: 17

Rob Kennedy
Rob Kennedy

Reputation: 163357

There are two basic techniques. The first uses PSAPI; MSDN has an example that uses EnumProcesses, OpenProcess, EnumProcessModules, and GetModuleBaseName.

The other uses Toolhelp, which I prefer. Use CreateToolhelp32Snapshot to get a snapshot of the process list, walk over it with Process32First and Process32Next, which provides module name and process ID, until you find the one you want, and then call OpenProcess to get a handle.

Upvotes: 17

aJ.
aJ.

Reputation: 35490

OpenProcess Function

From MSDN:

To open a handle to another local process and obtain full access rights, you must enable the SeDebugPrivilege privilege.

Upvotes: 1

Lloyd
Lloyd

Reputation: 29668

Check out: MSDN Article

You can use GetModuleName (I think?) to get the name and check against that.

Upvotes: 2

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