debugbreakprocess.cpp

debugbreakprocess.cpp

#include <windows.h>
#include <stdio.h>
#include <tlhelp32.h>
#include <vector>

int main(int argc, char **argv)
{
    if (argc != 2)
        return 1;

    const char *sibling_name = argv[1];

    // Enumerate all processes in the system.
    std::vector<PROCESSENTRY32> entries;
    {
        HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
        if(snapshot == INVALID_HANDLE_VALUE)
            return 2;

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

        if(!Process32First(snapshot, &entry))
        {
            CloseHandle(snapshot);
            return 3;
        }

        do
        {
            entries.push_back(entry);
        } while (Process32Next(snapshot, &entry));

        CloseHandle(snapshot);
    }

    // Find parent.
    DWORD current_pid = GetCurrentProcessId();
    DWORD parent_pid = 0;
    for (int i = 0; i < entries.size(); i++)
    {
        if (entries[i].th32ProcessID == current_pid)
        {
            parent_pid = entries[i].th32ParentProcessID;
            break;
        }
    }
    if (parent_pid == 0)
    {
        printf("No parent process.\n");
        return 4;
    }

    // Find named sibling.
    DWORD sibling_pid = 0;
    for (int i = 0; i < entries.size(); i++)
    {
        if (entries[i].th32ParentProcessID == parent_pid && strcmp(entries[i].szExeFile, sibling_name) == 0)
        {
            sibling_pid = entries[i].th32ProcessID;
            break;
        }
    }
    if (sibling_pid == 0)
    {
        printf("Sibling process '%s' not found.\n", sibling_name);
        return 5;
    }
    
    // Call DebugBreakProcess on sibling's children.
    for (int i = 0; i < entries.size(); i++)
    {
        if (entries[i].th32ParentProcessID == sibling_pid)
        {
            printf("Calling DebugBreakProcess on %s (%lu).\n", entries[i].szExeFile, entries[i].th32ProcessID);

            HANDLE process = OpenProcess(PROCESS_ALL_ACCESS, FALSE, entries[i].th32ProcessID);
            if (!process)
            {
                printf("Failed to open process %s.\n", entries[i].szExeFile);
                return 6;
            }

            if (DebugBreakProcess(process) == 0)
            {
                printf("DebugBreakProcess failed.\n");
                CloseHandle(process);
                return 7;
            }
               
            CloseHandle(process);
        }
    }
    
    return 0;
}