I want to make some debug console for my application. It should output some data and take input commands. How can I do this? The best way is updating console like: drawing information and prompt for input after the data.
I'm developing under Linux. For example, gdb could take input from console.
If you're familiar with socket programming (or actually, any other kind of IPC mechanism), you might want to enable some listener within your application, and develop an external application that will do all the "console" stuff for you, while communicating with the main application.
Let's suppose you have an application that has a single button and a single text label, and every time you press that button - the text label goes up by 1, from 1 to 2 to 3 etc.
You can build a socket listener into that application. When the socket listener accepts a new incoming connection, you'd start a connection thread that can:
Receive a "shutdown" command
Receive a "reset counter" command
Send an update regarding the current count on every click
etc.
Then you build another, external application, which connects to the main application, and sends messages to it, based on console input it gets from the user. It would also listen to incoming updates and show them to the user.
Using an external application for debug-controlling your main application is extremely helpful, with the following reasons being some of the advantages:
No matter how the debug application is buggy, it cannot hurt the release version of your main application.
All the code that deals with the console management, which is redundant to your main application, can be kept outside of the main app.
Making two projects out of it can make it easier to collaborate your work with someone else, as long as you are both aware of the protocol between the two sides.
Implementing what I suggested means you can debug your application remotely, in case you don't have access to the main application (for example, if it's on a customer site).
Related
Case: Click a URL in the browser and a video game that is currently running on user's desktop can ingest that data and do something.
I've been working on this for some time, but I don't know if I'm on the right path.
What I currently have:
A clickable URI in a webpage that can have different arguments for the client to recieve.
The URI scheme is registered in Windows. When clicking URI in the browser it will launch a c++ console 'launcher' or 'bridge' app that is already installed on the user's PC.
This 'launcher' is a middle-man that parses the URI arguments and communicates them to the main 'user' app (a video game) via IPC named pipes.
How do I:
In terms of UX, make the whole process discrete and seamless?
Specifically, I need to:
Keep launcher hidden from the user - no pop-up.
Needs to be only capable of running a single instance, even when invoked with new URI parameters. Do I just exit the current and create a new one?
User can click another URI in the webpage and the launcher will process the new arguments without displaying itself to the user.
Tech constraints:
Windows.
Preferably needs to be C++. C# could be a possibility.
Existing example:
Zoom conferencing software appears to works similar to this.
Clicking a URL in the browser launches a 'launcher' which starts the main app to video conference.
Closing that 'launcher' will minimize it into the system tray.
Clicking on a new link while the launcher is running does not start a new launcher, but it does start a new meeting.
How does something like this normally work?
The OS automatically creates a console for /SUBSYSTEM:CONSOLE apps. It doesn't automatically create a window for /SUBSYSTEM:WINDOWS. So use /SUBSYSTEM:WINDOWS.
Then, create the named pipe before creating the main window.
If the return code tells you a new pipe was created (use FILE_FLAG_FIRST_PIPE_INSTANCE), you're the primary instance, create main window and run normally, with an OVERLAPPED read on the named pipe to receive data from future invocations.
If instead you opened an existing named pipe, write your command line through the named pipe and exit without ever creating a window.
You don't need a separate launcher at all, and actually separating the launcher from the main application creates a race condition (a second launcher starts before the first instance managed to launch the main program / before the main program is up and running, doesn't see an existing named pipe, and thinks it is the primary copy). You are better off putting both sides of the argument-forwarding logic into the main executable.
Probably this already was answered here, but i not found.
Then i want know how execute a c++ console application/service (installs itself as service) of way that i can see all output's (printf()) during your execution (similar to how happens in a normal console application when system("pause");is used in main())? until now i'm able to see you console window only while Avast DeepScreen is executing he :-).
Thanks in advance.
EDITION:
I already insert getchar(); in ServiceMain() and a while (true) ... Sleep() but without success.
A service does not have a console window. And even if it did, a service does not run in an interactive desktop, so you couldn't see such a window anyway.
You need to rethink your logging approach. Either
write your log messages to the Windows Event Log, and use the Windows Event Viewer to see the messages.
create a separate visual app that runs in the user's interactive desktop and communicates with the service process to receive log messages. Then you can display the messages however you want.
Well, take the execution of any program using a c++ program, you can simply do it using the command prompt.
Just type in :
system(“path to the program”);
And, the program will be executed. If it’s a console window program, it will pop-up.
You can see the outputs, well, follow these :
1 The System.Diagnostics.Trace class has a similar interface to the Console class so you could migrate your code quite easily to this.
2 It can then be configured to output to a file. You can use the System.Diagnostics.EventLog class to write to the Event Log which you can then monitor using Event Viewer.
3 You can use the third-party open-source log4net library which is very flexible.
I have written a simple vc++ background application. What am trying is like a watchdog service that could monitor if the application is running or not. If the application crashed then the service should start the application
For creating a setup through windows installer am using only the app.exe and app.dll.
Is that possible to create this watchdog - service in the exe itself ?
Unfortunately I have no idea of how to write such a program, does anyone have some example code that would demonstrate this technique please?
if so then how to make the default exe and watchdog exe as a single application to install ?
Your best route would be to create a separate service to act as the watchdog. Technically, it's possible to have the service and the "real application" in the same executable. You can differentiate between the two depending on how the exe has been started, but it will make maintenance quite difficult.
This article might be of interest.
Here - http://yadi.sk/d/EtzBRSMi3FqVH - is my implementation of WatchDog app, working in systray. Do not mind that it's written with Qt - the main functionality is with WinAPI.
This app is watching in processes list for several processes and restarts them if can't find. The second feature is that it monitors all windows in system for suspicious window title (for ex. "'My Great App' causes a system error and will be closed. Send message to developers ?") and, if find, restarts them too
P.S. I didn't i18n it, but I think there will no troubles )
Update: (according to #CodyGray comment)
Here's pastebin's links: WatchDog.cpp and WatchDog.h
Such a watchdog can be set up to, for example, write to a file every minute (or whatever). If the file hasn't been updated in two or more minutes then there is most likely a deadlock in the application and it has to be restarted.
I'm trying to simulate the keypress events for Win+X on Windows 8 which should pop up a small menu, but I have been unable to get this to work by using SendInput. For any other combination of keys (e.g. Win+R, Win+E, Win+D) it works but not for Win+X. I've noticed that Synergy+ has the same problem, but the Windows on-screen keyboard doesn't. I have also looked at the parameters for SendInput that the on-screen keyboard uses but if I use exactly the same parameters in my application I still don't get the menu.
So my question, how do I get this to work? Or is there an alternative way to display this menu?
I've recently added support for this to our application. Glad we beat our competitor to it!
There are new UIPI restrictions in Windows 8. The most-used blocked shortcut is Alt+Tab, so you're going to want to do the workaround.
You have to mark your binaries with uiAccess="true" in the manifest. (For more detail on how to do this, google.) This manifest prevents binaries from being launched unless signed with a Microsoft-approved code signing certificate and installed in a "secure location" (system32 or Program Files/Program Files (x86)).
If you lanch your program from any helpers: The uiAccess binary can't be launched with CreateProcess from a medium integrity process (the manifest marks it as requiring "high" integrity). Instead, it's easiest to launch it using ShellExecute "open" to get the shell to elevate it. If using CreateProcessAsUser, you have to set TokenUIAccess to 1 using SetTokenInformation, or launching will fail.
Final provisos: note that uiAccess quite heavily restricts what a process can do. You can't receive UI input from normal (medium integrity) processes, so other applications can't interact with your windows. If you don't already follow good practices in separating your UI into a separate process, this would therefore be a good reason to do that. Alternatively, the tasks requiring uiAccess could be put into a small, self-contained helper binary and entirely separated from the non-UI process too. Your main app can run it as a high-integrity helper process that is sent instructions as required to perform those specific tasks (such as SendInput).
Finally, SendInput will work.
How can i programatically check if the windows shell (explorer) has loaded all startup programs & the user login process is over ?
There is a somewhat documented event you can wait for, but it is signaled when explorer has started loading. On XP this event is called "msgina: ShellReadyEvent" and "ShellDesktopSwitchEvent" on Vista. I linked to the sources of some alternative shells in a post related to this event.
Another alternative would be to listen for the Taskbar Creation Notification message. It can fire more than once so you would need to keep track of that.
On Vista+ there is one last alternative that might just work: Programs set to run at startup are part of a job object so they cannot run at high priority. If your program runs at startup you could maybe check for this, either by using IsProcessInJob or SetPriorityClass+GetPriorityClass in a loop. (SetPriorityClass will lie about its return value IIRC)