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


Question

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.

1
54
5/14/2009 7:22:26 PM

Accepted Answer

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

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

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;
}
74
1/31/2011 5:36:34 AM

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;
}

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