blocksleep.cpp

// Author: Vyacheslav, 2016.
// Use this code whatever you like.
// Mention me or send me a PM to make me happy if you like it. :)

#include <stdio.h>
#include <tchar.h>
#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#include <windows.h>
#include <Shlwapi.h>

#ifdef UNICODE
#define tprintf wprintf
#else
#define tprintf printf
#endif

int _tmain(int argc, LPTSTR argv[]) {
    DWORD ret = (DWORD)-2;
    if (argc <= 1) {
        printf(
            "Block PC sleep while child process is executing.\n"
            "Usage: blocksleep <exe_filename> [arguments]\n"
            "\n"
        );
        goto finish;
    }

    {
        EXECUTION_STATE old_state = SetThreadExecutionState(ES_CONTINUOUS | ES_SYSTEM_REQUIRED);
        if (!old_state) {
            printf("ERROR: Can't set thread execution state via SetThreadExecutionState WinAPI finction\n"
                "See https://msdn.microsoft.com/ru-ru/library/windows/desktop/aa373208(v=vs.85).aspx for more info.\n");
            goto finish;
        }

        STARTUPINFO si = {};
        si.cb = sizeof(si);
        si.dwFlags =  STARTF_FORCEOFFFEEDBACK;
        PROCESS_INFORMATION pi = {};
        LPTSTR cmd = PathGetArgs(PathGetArgs(GetCommandLine()));
        if (!CreateProcess(argv[1], cmd, NULL, NULL, true, CREATE_DEFAULT_ERROR_MODE, NULL, NULL, &si, &pi)) {
            tprintf(_T(
                "ERROR: Can't start process \"%s\" with CreateProcess function\n"
                "Command line : %s\n"
                "See why this could happen at https://msdn.microsoft.com/ru-ru/library/windows/desktop/ms682425(v=vs.85).aspx\n"
            ), argv[1], (*cmd) ? cmd : _T("<empty>"));
            goto finish_reset_state;
        }
        CloseHandle(pi.hThread);
        ret = (DWORD)-3;

        DWORD result = WaitForSingleObject(pi.hProcess, INFINITE);
        if (result != WAIT_OBJECT_0) {
            printf("ERROR: WaitForSingleObject function failed with code 0x%08x\n", result);
            goto finish_close_process;
        }
        if (!GetExitCodeProcess(pi.hProcess, &result)) {
            printf("ERROR: GetExitCodeProcess function failed.\n");
            goto finish_close_process;
        }
        ret = result;
    finish_close_process:
        CloseHandle(pi.hProcess);
    finish_reset_state:
        SetThreadExecutionState(ES_CONTINUOUS | old_state);
    }
finish:
    ExitProcess(ret);
    return 0;
}