I need to execute a file.exe with certain commands from my React Native Windows app

[AlmTalal]

Hello ! I need to execute a file.exe with certain commands. At the begining I thought that this is gonna be an easy task thanks to child-process library from node js. However this library is not available for react.

After that i followed this documentation for being able to call this WinRT API for executing commands on the terminal. This did not work because of access denied problem (I tried by giving the windows requirment, it did not worked).

My final option was to create the native module by myself, I did a module for my app (not a distributable one) in c++, this is the implmentations :

#pragma once
#include "pch.h"
using namespace winrt;
#include <iostream>
#include <windows.h>
#include <string>
#include <sstream>
#include <stdio.h>

using namespace std;

REACT_MODULE(MyNativeModule);

struct MyNativeModule
{
    REACT_METHOD(Add, L"add");
    std::string Add(std::string path, std::string commandE) noexcept
    {
        STARTUPINFO si;
        PROCESS_INFORMATION pi;
        ZeroMemory(&si, sizeof(si));
        si.cb = sizeof(si);
        ZeroMemory(&pi, sizeof(pi));
        char cmdArgs[] = "C:\\Users\\almta\\OneDrive\\Escritorio\\IntTFHKA IntTFHKA SendCmd(!000000100000001000Item 1)";
        wchar_t wcmdArgs[256];
        MultiByteToWideChar(CP_ACP, 0, cmdArgs, -1, wcmdArgs, 256);
        if (!CreateProcess(NULL, wcmdArgs, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi)) {
            DWORD error = GetLastError();
            LPVOID errorMsg;
            FormatMessage(
                FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
                NULL,
                error,
                0,
                (LPWSTR)&errorMsg,
                0,
                NULL
            );
            std::wstring errorMessage(static_cast<const wchar_t*>(errorMsg));
            LocalFree(errorMsg);
            std::wcout << L"Error: " << errorMessage << std::endl;
            return "Error: " + std::to_string(error);
        }
        WaitForSingleObject(pi.hProcess, INFINITE);
        CloseHandle(pi.hProcess);
        CloseHandle(pi.hThread);
        return "success";
    }
};

However, here I'm having three problems :

1. When I execute: char cmdArgs[] = "C:\\Users\\almta\\OneDrive\\Escritorio\\IntTFHKA IntTFHKA SendCmd(!000000100000001000Item 1)"; I get error: 5, this means access denied.
2. When I execute: char cmdArgs[] = "./Assets/IntTFHKA IntTFHKA SendCmd(!000000100000001000Item 1)"; I get error : 2, this means file not found
3. When I execute: char cmdArgs[] ="dir"; The terminal appears, but with "_" as the only thing visible.

Someone has any idea of how could I make this work. At this point I don't know what else to do so I'm open to any idea

[Victor0814gui]

I'm not sure if this is possible since UWP is a sandboxed environment, which restricts the usage of certain APIs, but you can check further at #11793.

[AlmTalal]

What did you test on C#, can you share the code ?

[Victor0814gui]

My mistake, haha. I meant to talk about the projects I worked on using C# that access Win32 APIs, but I can't share the code. However, it's very similar to this one: https://github.com/microsoft/react-native-windows-samples/tree/main/samples/AppServiceDemo

[AlmTalal]

Oh thanks jajaj, I was able to access to Win32 API's however the namespace that i needed to use is forbidden

[chrisglein]

Short answer is that an RNW app is a UWP app and has the same limitations. RNW allows you to create your UI using JavaScript and React patterns, but it can only do what a UWP app can do. So the answers available about UWP apps are going to be relevant to you. From some quick searching, here are some threads:

• https://stackoverflow.com/questions/33925096/how-to-execute-process-commands-or-similar-using-a-universal-windows-platform
• https://stackoverflow.com/questions/51141474/in-which-cases-can-createprocess-be-used-on-uwp

[ivxvm]

Oh well, this is very unfortunate restriction. It seems I was wrong that I could build a beautiful and simple react-native-windows launcher for a game, time to switch to proper native languages like Rust.

[AlmTalal]

Hey, Actually they do it for the good sake of the users that wil use the developed app (executing unknown .exe files can lead to hacks). However I solved this by using react native windows WinRT modules. You can take a look at it, it may solve your problem

[stack-99]

Can you give an example of how you did it please? or which links I should look into

[AlmTalal]

You have to know what does that exe file do, after that you can use WinRT apis and try to copy that behavior. I don't know what exactly you want to do, but in my case it worked

[stack-99]

Well I did manage to launch a process using win32 api - CreateProcess function because I am unable to find the class FullTrustProcessLauncher in my c++ project. I tried different windows 10 sdks and it still wasn't accessible through Windows::ApplicationModel.

Even though I managed to use CreateProcess I am still limited with the things that I can do in terms of permissions...
I can't access or create new files from external directories.

... Edit:

FullTrustProcessLauncher is the way to go (add desktop extensions as reference). Thanks!