Turning on a specific program at a specific time and turning off the computer at another specific time - ruby

I decided to write a program in RUBY in which the following things should be done:
1 - this program must run a specific program (for example utorrent) at a specific time (for example 1 pm).
2 - this program must turn off my computer at another specific time.
I don't have any idea about the algorithm and manner of writing such program.

One of the easiest ways to do this is to simply send kill signals to the processes, requesting the app shut down normally (Linux), or in Windows use taskkill.
To shutdown a machine in Windows, you can use shutdown /s /f which forcibly closes any programs that are running, and turns the computer off.
No matter which way you do it, you'll basically be running the enter link description heresystem() command in Ruby, which runs command line commands. To make your app portable, you simply look up how to do these tasks in each target OS, and you're done.
Two more alternatives that work the same as your Ruby proposal, but which are not as easily portable:
Write a batch file in Windows that calls taskkill, or a bash script on Linux. Unless the program in question provides a specific way to shut it down via its own command-line parameters, this should work for any/all applications.
You can also use Task Scheduler in Windows, or cron in Linux to do the same thing.

Related

Monitor what processes are writing to a file on Windows from Go

I am writing a Go app targeted at macOS and Windows and that needs to monitor what processes write to a file at a given path. More specifically, I need to verify that only one specific process writes to the file for the duration that my program is running. On macOS, I can monitor the file via the built-in fs_usage command. Does anyone have an idea for how to achieve equivalent monitoring on at least Windows 10 and later without requiring the user to install any additional software.
Note that I don't expect for there to exist a pure Go solution and I don't mind interoperating to achieve the desired result.

Figuring out how one program launches another program on Windows

I have a Windows program -- a vendor-provided benchmark utility -- that launches an existing game on my system using a set of launch options. I'd like to figure out what those launch options are. Is there any way to detect how the benchmark utility is launching the game?
More generally, is there some tool I can use to detect when and how one process launches another process on Windows?
As I was faced with the same problem, I figured out a simple, yet for my needs great solution.
I exchanged the called program with a simple custom-written c-program which prints all passed arguments into a logfile.

Supporting two shells in windows

I'd like to write my own (very simple) explorer.exe alternative that I could actively switch between without having to restart my computer.
Is it possible to run two shells simultaneosly (or to write a program that temporarily disables the current shell)?
If not, is it possible to stop explorer without it restarting itself, and have my shell start itself instead?
Edit
More info: I'd like to write a simple productivity tool for myself. I want to set up a very simple task manager that prevents me from starting/opening/using anything but a whitelisted set of applications I list ahead of time. Locking me into that set of apps for whatever time period I've set. If there's another (better) way to prevent people from shutting down my app, switching from my app (with alt-tab, etc) I'm all ears.
Note: I'm fine with the app/shell/whatever being escapable by restarting my computer. I just want to make it massively inconvenient to switch to being distracted, and I wanted to learn a bit more about the Windows API.
See this question for details about writing a shell.
No, there can only be one real shell process (SetShellWindowEx only works when there is no other shell process) WH_SHELL can be used by other processes and it might be enough for your needs (Maybe in combination with IShellExecuteHook)
When explorer.exe is started and it detects a different shell it will not display the taskbar, just a file browser window. Explorer also looks at the shell value in the registry IIRC. You might also want to look into the shift to exit trick.

How to restart program automatically if it crashes in Windows?

How can I start my program automatically if it crashes on windows 2003 server? Sometimes my program just crashes, is there a way in windows or settings that I can set?
There are several ways to create a process supervisor/guardian process on Windows.
First, is to leverage windows command line capabilities. Create a bat file:
#echo off
:start
start /w "your app to watch.exe"
goto start
start /w will wait for the process to exit. When the process crashes and exits, the bat script will relaunch it.
Another option is to use free supervisor tool https://github.com/chebum/Supervisor. It allows to restart the crashed app, plus it allows to monitor two or more apps at once and it will automatically close these apps when supervisor's window is closed.
The usual approach is to run what is known as a guardian process. This is a separate process, often a service, that monitors the state of the main process. When the guardian detects that the main service has died, it re-spawns it.
To the very best of my knowledge, there is not built in Windows functionality to do this for you.
Notice: running self-looping bat files can be useful, but unless you know what you're doing, they can wreak all kinds of havoc. This goes especially if you run them on startup. You have been warned.
Anyway. I just remembered something from my 286 days, when I played around a lot with BAT files. If you write the file
yourprogram.exe
some other event
the BAT file will run yourprogram, and then pause and wait around in the background until the program exits. After that it will run "some other event". This used to be kind of annoying if you wanted to run multiple things at once, but here it's actually useful. Using this, it's possible to make it run a loop that restarts the program (and reruns the bat file) as soon as it exits. Combine this with https://superuser.com/questions/62525/run-a-completly-hidden-batch-file, and you'll never even see it happening.
The final BAT file ("restart.bat" in this example) will look something like:
c:\[location]\yourprogram.exe
wscript "C:\[location]\invisible.vbs" "C:\[location]\restart.bat"
That's about it. Start the program (on startup via task or even just startup folder) with line 2, and this ought to solve your problem :)
Oh, if you want to stop the loop, just rename the bat file or put "// " in front of the two lines, save it, and exit the program.
If the program you are running requires admin rights, the solution I found was using psexec (http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx) to run both the program and the bat with elevated privileges. In that case the BAT will look like:
c:\[location]\psexec -h c:\[location]\yourprogram.exe
c:\[location]\psexec -h wscript "C:\[location]\invisible.vbs" "C:\[location]\restart.bat"
Then you run the bat as administrator, or run the second line (without the psexec part) from task scheduler with elevated privileges. BEWARE: running it as a normal user and clicking "no" on the UAC prompt gave me a BSOD, probably because it looped "can't run program because of lacking privileges" a couple of billion times or something :)
You can use RegisterApplicationRestart.
"If you register for restart and the application encounters an
unhandled exception or is not responsive, the user is offered the
opportunity to restart the application; the application is not
automatically restarted without the user's consent. "
For automatic restart without user intervention, there is also RestartOnCrash. Works with all Windows versions.
I was looking for something similar. There are two options to handle this - either you can write a small script by yourself or use something that is already existing.
After some googling I came across this nice list. The blogger has compiled about 8 tools to automatically restart a crashed or closed application.
Unfortunately there are no settings in Windows to automatically restart a regular program when it crashes.
Do you need to actively interact with your application's GUI? Some of the Service Wrappers (designed to run any application as a Windows Service) will monitor your application and restart it when it fails, but be sure investigate Session 0 Isolation to ensure that it won't get in the way.
You may use some special app like BDV SystemEvents or any other. It allows you to specify application which will be started if some another application is closed. Specify the same application as a Condition and as an Action and you will get expected results.

Scripting for safe file backup under windows

I need to back up some large files that are being written to disk by a process. The process is perpetually running, and occasionally dumps large files that need to be moved over the network. Having the process do this itself is not an option, as the process locks out users whilst it is doing file dumps.
So, this runs under a windows machine, and as a primarily linux user, I am not entirely certain how to do this...
Under linux I would simply use a cron job in the folder (I know the glob that will match the output files), then check lsof, to ensure that the file is not being written to, such that I don't try to copy a partially complete file. Data integrity is critical, so I would normally md5 the files before and after the copy.
So I guess my question is -- how does one do this sort of stuff under windows? I feel like I am kneecapped from the start -- I can use python, but I can't emulate lsof, nor cron to do the task scheduling.
I tried looking at "handle" -- but it needs admin privelidges at execution time, which is also not an option. I can't run the backup process as an admin, it has to run with user privs.
Thanks..
Edit: I just realised I could keep the python instance running, with a sleep, so task scheduling is not a problem :)
For replacing cron you can use the "Task Scheduler" in windows to start your script every few minutes (or specific times).
For lsof the question was discussed here : How can I determine whether a specific file is open in Windows?

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