I am currently creating a c program that counts all of the keys I press in a day and sorts the key types by amount, so I can tell which ones I press most often. It was more of a side project than anything else but I have become annoyed with the fact that my program doesn't seem to be able to intercept any input to password fields. I suppose this is a good thing, but I have been spending hours looking at documentation and trying to figure how to do this. I am not trying to create any sort of malicious software. Is there a way around this? My program is running as root. I am using the ApplicationServices framework and CGEventRef and the CGEventTapCreate funcion. Should I be using a different framework or struct? Also, is there a difference between kCGHIDEventTap, kCGSessionEventTap, and kCGAnnotatedSessionEventTap? I have tried using each of them and it does not seem to make a difference in my program.
I am running this on OS X 10.9
UPDATE
Apparently I cannot capture keystrokes going to terminal either, which is where I spend most of my time on my laptop. This is a problem.
What you want is fairly complicated and requires a kernel extension. The interprocess communication is also not trivial. Take a look at logKext, specifically logKext.cpp. That project actually logs the keystrokes to an encrypted file. You should be able to pull everything you need from it.
Related
I am very new at this and trying to get an understanding of this. I have read a lot on the DroneKit-Python site trying to figure out how exactly am I able to communicate with it.
Drone I am currently using is Iris+
I have looked more and there are software that already provide this, but I want to be able to control it plus more.
I want to set waypoints, tell it to then fly give the way points and keep going to them. Also, to be able to arm itself, which is in the example, and override the safety mechanism.
Here is the basic of what I am trying to use it for. Have it fly up at a certain time. Go to the waypoints 1,2,3,1,etc.. Then after X amount of time or on low battery go back to launch point and land.
I have found plenty of code that provides what i need to do, though I don't know if it will work and more importantly I don't even know how to start programming for this. Maybe I have the wrong approach in doing this?
I kind of want this to be a light API, so that in the future I can make a simple UI on my phone and insert some coordinates to give it ways points and that is it. I know there is software out there already that does it, but I want to remove the need for touching the drone. I want it to start and end autonomously.
If anyone could help provide some info that much would be greatly appreciated.
Assuming you have no companion computer (Iris+ does not by default), you are OK with running a ground station app (you won't be out of range to send commands to "end mission on time expiry") and that driving the behaviour from your phone is important, I would be looking at DroneKit Android.
Some notes:
You're going to have to touch the drone at some point to attach the
batteries.
You can arm the device from dronekit
You can override the safety mechanism from a script. I hope you have
a lot of money to pay for the new drones you're going to have to buy when they crash and all the litigation from damaged people and property (in other words "don't do it".
The default behaviour is to return the device to launch (RTL) on low battery. This is convigurable
Setting a time is more "problematic". You can have a timer in a script that then sends return-to-launch but the script needs to be connected to the UAV. This means that either you have to be running in a connected ground station (which might potentially be out of range) or on a companion computer.
Iris+ does not have a companion computer. You have to install one or connect from a Ground Control Station.
DroneKit-Python runs on Linux, MacOSX or Windows. You can't just run it on an ordinary phone, though you could find some other mechanism to send messages/scripts to it running on a companion Computer.
DroneKit Android runs on Android. We do have a planned iOS version too. In theory these could run on a companion computer, but in practice currently these are only used as ground stations.
I'm trying to write a simple terminal-based dungeon-style game in C, but I want to give the user real-time feedback on various processes that they affect.
I remember using kbhit() years ago, but I also remember the cpu going to 100% during the life of the program. I'd like to avoid this entirely. And I'm working in Linux now.
Let's say that you're in a dungeon in a text-based adventure game. The dungeon is sealed off. There's only so much air in the room. The longer you remain there, the lower the oxygen gets. I want to report the oxygen level in the room in real-time, while at the same time accepting commands from the user.
Is there a way to do this?
EDIT: The one idea I had was to use two terminal windows. Commands are taken in one terminal, the results of those commands could be written to a text file. The other terminal will have a program running that runs real-time stuff, and checks periodically on the same text file for updates on rates, etc. Ideally, I'd like to do this in one window.
Sure there is a way to do that. Have a look at ncurses. I think that is the way to go.
I asked this question in the Raspberry PI section, so please forgive me for posting this here again. Its just there doesn't seem to be as active as this section of the forum. So, onto my question...
I have an idea and I'm working on it right now. I just wanted to see what the community's thought was on using a screensaver as digital signage. Every tutorial I've read shows someone using chromium in kiosk mode, and while that's fine and works well for some uses, it doesn't work for what I need. I have successfully completed a chromium kiosk, and it was cool. But the signage that I need to create now, has to work without internet. I've thought about installing LAMP locally on the PI, and still using chromium. I still may have to if this idea doesn't pan out. All I need from the signage is a Title Message in the top center, and a message body underneath it, with roughly 300-400 character limit. My idea is to write a screensaver module, in C, that will work with a screensaver such as xscreensaver. The module would need to be able to load messages from a directory on the pi. Then for my clients to update their signage text, I would write a simple client that sent commands as well as the text via SSH to the pi. I want to know what other people think about this. Is it a good idea? Bad idea? Should I "waste" my time doing something like this?
Thanks in advance.
I am already using a rPi as digital signage, just over a year. I am using two different setups:
version 1 uses Raspian loading xdesktop and qiv image viewer to cycle images stored on the Pi itself, synchronized with a remote server. The problem I found was power and SD stability, when the power fails, which it will do no matter what, just when... The Sd card can become corrupt due to all the writing that Raspian does all the time. Certainly does not really need to write to SD.
version 2 uses a RO-filesystem and a command line image tool. Uses the same process to show images from local, and sync with server. But power fail causes no ill effects.
I am not using screensaver to display images, that seemed redundant to me, and unnecessary to wait for the SS to start just to display the images.
Some of the images are created using imagemagik, which is nicely dynamic where needed.
I'm writing a program in C and want it to have an option that will keep a mac laptop awake even if the lid is closed so processes can continue. There seems to be very little information available on this topic so I really don't know where to begin. If anyone knows how to accomplish this or where I can find more information I would really appreciate (i.e. will I need to work with the BIOS for this or are there built in functions?). Also, if it's easier to do it in another language that is fine as I'm not stubbornly set on using C.
You need to write a kernel extension for this. The OS doesn't support it by default because the laptops aren't designed to properly cool themselves with the lid closed and internal display enabled. SleepLess is a $10 utility that'll do what you want, too. If you warp the display or something, it's your own fault. :-).
If you want to write something yourself, LidSleep.kext looks like a good start (it does the opposite, i.e. sleeping on lid close) and comes with source code.
(It is possible and supported to wake up some Mac laptops with the screen closed by using an external input device.)
You can do this using the I/O Kit framework, see QA1340 listing 2 for sample code using IOPMAssertionCreateWithName to temporarily prevent sleep.
The link to LidSleep.kext listed above is not working, so I can inform that the author of NoSleep has made the source code available here, so you can see for yourself how it can be done:
https://code.google.com/p/macosx-nosleep-extension/
If your laptop is a reasonably recent model, you don't need to add anything. If you are running Lion, it simply works. If you're running an older OS you have to wake up the laptop by sending it a keystroke or mouse click from an external keyboard or mouse. See http://support.apple.com/kb/ht3131
Is it possible to listen for a certain hotkey (e.g:Ctrl-I) and then perform a specific action? My application is written in C, will only run on Linux, and it doesn't have a GUI. Are there any libraries that help with this kind of task?
EDIT: as an example, amarok has global shortcuts, so for example if you map a combination of keys to an action (let's say Ctrl-+, Ctrl and +) you could execute that action when you press the keys. If I would map Ctrl-+ to the volume increase action, each time I press ctrl-+ the volume should increase by a certain amount.
Thanks
How global do your hotkeys need to be? Is it enough for them to be global for a X session? In that case you should be able to open an Xlib connection and listen for the events you need.
Ordinarily keyboard events in X are delivered to the window that currently has the focus, and propagated up the hierarchy until they are handled. Clearly this is not what we want. We need to process the event before any other window can get to it. We need to call XGrabKey on the root window with the keycode and modifiers of our hotkey to accomplish this.
I found a good example here.
I think smoofra is on the right track here; you're looking to register a global hotkey with X so that you can intercept keypresses and take appropriate action. Xlib is probably what you want, and XGrabKey is the function, i think.
It's not easy to learn, I'm afraid; I did locate this example that seems useful: TinyWM. I also found an example using Java/JNI (accessing the same underlying Xlib function).
You should look at the source code of xbindkeys.
Xlib programming is pretty arcane, documentation is hard to find, and there are subtle portability issues. You'll be better off copying some battle-hardened code.
One way to do it is to have your application listen on a certain port, or socket file, for incoming requests.
Then you can write a small client application that connects to that port or socket file and sends commands to the running application.
Then you can configure your window manager to bind certain key combinations to launch your small client app.
In UNIX, your access to a commandline shell is via a terminal. This harks back to the days when folks accessed their big shared computers literally via terminals connected directly to the machines (e.g. by a serial cable).
In fact, the 'xterm' program or whatever derivative you use on your UNIX box is properly referred to as a terminal emulator - it behaves (from both your point of view and that of the operating system) much like one of those old-fashioned terminal machines.
This makes it slightly complicated to handle input in interesting ways, since there are lots of different kinds of terminals, and your UNIX system has to know about the capabilities of each kind. These capabilities were traditionally stored in a termcap file, and I think more modern systems use terminfo instead. Try
man 5 terminfo
on a Linux system for more information.
Now, the good news is that you don't need to do too much messing about with terminal capabilities, etc. to have a commandline application that does interesting things with input or windowing features. There's a library, curses, that will help. Lookup
man 3 ncurses
on your Linux system for more information. You will probably be able to find a decent tutorial on using curses online.