Can an operating system be considered as Graphical User Interfaces? - user-interface

So I've been searching the Internet and I can't seem to find any answer that explicitly explain why operating systems can be considered as Graphical User Interfaces. So I' am hoping someone would explain why it can be a GUI or the other way around.
Thank you!

I my view an operating system is the complete interface between all interested parties (hardware, services, user) whereas a GUI just gives the users (some predefined) access to the system resources. Users might even run more than one GUI on a single system. Each user might choose her or his own flavour of GUI which fits them best to interact with the system. They may even choose to use no GUI at all and be content with a command line interface (CLI).
For me GUIs are a component of an os and not the other way around.
I hope this helps to sort out the different concepts.

Related

Help needed with windows hooks

I am working on building a system that can monitor how users react to security alerts on their systems (software updates, warnings etc.). It also needs to monitor the web traffic and the processes running on the system and I am looking to the community to help me design this system. We intend to provide users with test laptops and monitor their behavior over a period of time to see how they react to security alerts thrown by various applications and the OS(windows in this case).
Following are my questions
Can I use windows hooks to solve the first problem i.e finding how users reacted to the alerts thrown by various applications. Specifically, can global hooks be used to solve this?
(How this information should be collected (XML?) and relayed back to a server(how frequently?) is another problem)
Can I do this in C# or it has to be done only in c++ or VB?
Do you know any alternate approach to solve the problem? Is there any software that has these capabilities.
I have many more questions but getting these answered would be a good first step. Really hoping for some good insights from the knowledgeable people on this community
Thank you in advance
Edit:
Example scenario is when adobe prompts you to update the flash player or the antivirus prompts you to update definitions or any application displays a notification(security related having keywords like update, warning, install etc.) needing the user to take some action. Windows system updates is another example. I want to know how the user reacted to these alerts/notifications/updates (which are typically a pop-up window). So i was wondering if i placed a global hook that can monitor the content of the windows displayed on screen and notify me(server) when certain words like update, alert, warning etc. appear in the content/title of the windows and what the user did with the message(dismissed it, Oked it etc). Unfortunately, i do not have any more specifications than this. I can use anything I want to achieve this and I am not clear on what my choices are.
Edit 2:
After having reviewed my requirements and having read about hooks, I feel like I could achieve this by a combination of hooks and the following textGrab SDK, http://www.renovation-software.com/en/text-grab-sdk/textgrab-sdk.html. I want some guidance to know if I am on the right track. I am thinking if I can install hooks then it gives me handles to all possible windows on the screen and I can use the textGRAB SDK to look for certain keywords in those windows. Although this may capture some interesting text, I am still not sure how I will know what action the user had taken on the window. Anybody having any experience with either hooks or textGRAB, please let me know if this looks like a reasonable thing to do. If the community has some other Ideas on how I could possibly monitor security related messages thrown by any application in the system, please suggest. I am looking forward to some useful advice for completing a challenging project.
First of all, you need to define, how you will "see" security alerts in code. "Security alert" is quite a vague term. Will it be some window with some caption and some message to the user or ... ?
Next, about web and processes: Windows hooks won't help you with your task. They are more low-level and not as advanced as you'd need. You can't hook network traffic (you need either network filter driver for pre-Vista or Microsoft Filtering Platform for Vista and later). See this question for some information about checking the process list with C# (there seems to be no easy way to catch process startup either).
It honestly sounds like you need a more solid direction. I commend you for trying to provide details, but It appears that you still need more information about your problem(s)..
I will attempt to answer some of your questions, but like I said - it sounds like you need to know more about your problems before we can provide you with optimal answer(s).
-Alerts is too vague a term, you will need to define this better. Are these 'alerts' applications that YOU have control over or are they third party applications? Not every application will show an 'Alert' in the same fashion, and even if they did - I think using a System Level Hook would probably be too problematic to implement your solution with. I'm not saying it's necessarily impossible, but you're talking about possibly implementing a different set of logic(to determine the data for a given application's Alert(s)) for each application that you want to monitor.
-It's impossible for any of us to determine the optimal storage mechanism for your particular needs, that is something that you will either need to provide more details about or decide on your own.
-How often you collect data is also something that you will have to either provide more details for or decide for on your own.
-C/C++ Would probably provide you with the most portable solution, although there is nothing preventing you from using c# to call Win32 API. (Not everyone has the .NET framework installed - believe it or not)
-The problem that you mentioned appears to be a somewhat specialized problem... I don't know of any existing software that will do everything that you want to do.
Another possible issue that you haven't touched on:
You haven't specified your target audience for this 'service', but I want you to know that if I found an application monitoring as many events as what you're talking about doing, I would promptly remove it and write a nasty letter to the company that wrote it.
In summary, Read this Article on hooks to get a better understanding of how they work.

is it worth keeping the OS look and feel?

Is it worth to try to keep your GUI within the system looks ?
Every major program have their own anyways...
(visual studio, iexplorer, firefox, symantec utilities, adobe ...)
Or just the frame and dialogs should be left in the system look 'n feel range ?
update:
One easy exemple, if you want to add a close button to your tab, usually you make it against your current desktop theme. But if the user has a different theme, your close button is out of place, it doesn't fit the system look anymore.
I played with the uxtheme api, but there is nothing much you can do, and some themes i've seen are incomplete sets.
So to address this issue, the best way i see, is to do like visual studio/firefox/chrome roolup your own tab control with your theme...
I think, that unless your program becomes a very major part of the users life, you should strive to minimize "surprises" and maximimze recognizability (is that even a word?).
So, if you are making something that is used by 1.000 people for 10 minutes a day, go with system looks, and mechanisms.
If, on the other hand, you are making something that 100 people are using for 6 hours a day, I would start exploring what UI improvements and shortcuts I could cram in to make those 6 hours easier to deal with.
Notice however, that UI fixes must not come at the expense of performance. This is almost always the case in the beginning when someone thinks that simply overriding the OnPaint event in .Net will be sufficient.
Before you know it you are once again intercepting NC_PAINT and NC_BACKGROUNDERASE and all those little tricks to make it go as fast as the built-in controls.
I tend to agree with others here- especially Soraz and Smaci.
One thing I'll add, though. If you do feel that the OS L&F is too constraining, and you have good grounds for going beyond it, I'd strive to follow the priciple of "Pacing and leading" (which I'm borrowing here from an NLP context).
The idea is that you still want to capitalise as much as possible on your intended audidences familiarity with the host OS (there will be rare exceptions to this, as Smaci has already covered). So you use as much as possible of the "standard" controls and behaviours (this is the "pacing") - but extend it where necessary in ways that still "fit in" as much as possible (leading).
You've already mentioned some good examples of this principle at work - Visual Studio, even Office to some extend (Office is "special" as new UI styles that cut their teeth here often find their way back into future OS versions - or de-facto standards).
I'm bringing this up to contrast the type of apps that just "do it their way" - usually because they've been ported from another platform, or have been written to be cross-platform in GUI as well as core. Java apps often fall into this category, but they're not the only ones. It's not as bad as it used to be, but even today most pro audio apps have mongrel UIs, showing their lineage as they have been ported from one platform to another through the years. While there might be good business reasons for these examples, it remains that their UIs tend to suck and going this route should be avoided if in any way possible!
The overriding principle is still to follow the path of least surprise, and take account of your user's familiarity with the OS, and ratio of their time using your app to others on the OS.
Yes, if only because it enables the OS to use any accessability features that are built in like text-to-speech. There is nothing more annoying for someone who needs accessability features to have yet another UI that breaks all the tools they are used to.
I'd say it depends on the users, the application and the platform. The interface should be intuitive to the users, which is only the same as following system UI standards if they are appropriate for those users. For example, in the past I have been involved in developing hand held systems for dairy and bread delivery on Windows CE hand helds. The users in this case typically were not computer literate, and had a weak educational backround. The user interface focussed on ease of use through simple language and was modelled on a pre-existing paper form system. It made no attempt to follow the Windows look and feel as this would not have been appropriate.
Currently, I develop very graphical software for a user group that is typically 3rd level educated and very computer literate. The expectation here is that the software will adhere to and extend the Windows look and feel.
Software should be easy and intuitive where possible, and how to achieve this is entirely context dependent.
I'd like to reply with another question (Not really Stackoverflow protocol, but I think that, in this case, it's justified)
The question is 'Is it worth breaking the OS look and feel?'
In other words,
Do you have justification for doing so? (In order to present data in some way that's not possible within normal L&F)
What do you gain from doing so? (Improvinging usability?)
What do you lose from doing so? (Intuitiveness & familiarity?)
Don't simply do it 'To be different'
It depends on how wide you would define system look'n feel... But in general, you should keep it.
Do not surprise the user with differentiating from what he is used to. That's one of the reasons why we call him user ;-)
Firefox and Adobe products usually don't because they are targeting several plattforms which all have their own L&F. But Visual Studio keeps the typical Windows L&F. And, as long as you are developing only for Windows, so should you.
Apart from the fact that there is no well-defined look-n-feel on Windows, you should always try to follow the host platform native L&F. Note however that look-n-feel is just as much about how a program behaves as how it looks. Programs which behave in a counter-intuitive way is just as annoying as programs sporting their own ugly widgets.
Fraps is a good example (IMHO) of a program which is actually very useful, but breaks several user interface guidelines and looks really ugly.
If you're developing for Apple's Mac OS X or Microsoft Windows, the vendors supply interface guidelines which should be followed for any application to be "native".
See Are there any standards to follow in determining where to place menu items? for more information.
If you are on (or develop for) a Mac, then definitely YES!
And this should be true for Windows also.
In general, yes. But there's the occassional program that does well despite being not formatted for all the OSes it runs on. For example, emacs runs pretty much contrary to every interface guideline on OS X or Windows (and probably even gnome/KDE) and it's not going away any time soon.
I strongly recommend making your application look native.
A common mistake that developers who are porting an application to a new platform seem to make is that the new application should look-and-feel like it does on the old platform.
No, the new application should look-and-feel like all the other application that the user is used to on the new platform.
Otherwise, you get abominations like iTunes on Windows. The same UI design may be exactly right on one platform and very wrong on the next.
You will find that your users may not be able to pin-point why they dislike your application, but they just feel it hard to use.
Yes, there are valid exceptions, but they are rare (and sure enough, they tend to be the major applications like Office and Firefox, rather than the little ones). If you are unsure enough to have to ask on StackOverflow, your application isn't one of them.

Do Character User Interfaces have a future?

We've got products built both with GUI and CHUI. Going forward, we're looking at redesigning a lot of our software and mainly taking the route of going all GUI. My question to the group is, do we need to account for keeping a CHUI around? What are the advantages of CHUI over GUI? Many times in the past people have said that CHUI is faster because you don't need a mouse. I argue that GUI can be just as fast with the right keyboard shortcuts, hotkeys and/or touch screens.
Is CHUI something we should no longer consider if hardware no longer provides a constraint?
Also to clarify, when I speak about CHUI I mean a CHaracter based User Interface, and I'm also mainly concerned with the effective presentation of data to an end user.
There have been some fantastic responses that have highlighted the importance of having a command line based interface for automation and scripting based tasks which I will certainly take to heart when we begin the design!
The primary benefits of a CHUI (that is something with forms and fields, not necessarily command line interfaces) is the keyboard for navigation and consistent layout. That is key.
If your GUI can be completely, and efficiently, keyboard navigated, then your CHUI user base should be happy. This is because in time, the users simply "type" their commands in to the system without "seeing the interface". They don't need to "discover" the interface, which is a primary feature of the GUI.
While CHUIs appear to be dinosaurs, they are still functional and usable. Most folks once they're trained (notably POS/Counter workers, but even back office scenarios like factory or warehouse floor, etc) have no problem using a CHUI.
But the key is the keyboard support so the user don't have to wait for the screen to catch up with them. Seeing a skilled operator with a mastery of the keyboard can make an application fly. You barely have a chance to see popup windows and what not.
You should poll your customers, not programmers. If your customers, who use your applications, want a CHUI, even if all your developers think it's a waste of time, you build it, because the customer is always right (except for when they're wrong).
You should absolutely still consider it. Most importantly, command line programs can be automated (and chained together in scripts) much more easily than GUIs (typically). I can't imagine working with a source control tool which didn't have a command line interface - although obviously having a GUI is useful too.
Now whether you need a command line version for your particular app is hard to say without knowing what your app does. Do you need automation and scripting? Might someone want to VPN in and run it from a very bad connection, and thus appreciate low bandwidth?
Note that MS certainly doesn't believe the command line is dead - or they wouldn't have created PowerShell.
I agree with Eli that your customers should have final say, but if you can keep the meat of your program from being too interwoven with the GUI(or CHUI), then production cost to make both available should be minimal.
If you write apps for unix and you need to handle users who telnet / ssh to your box then you will need command line interfaces.
I would say it depends on your target. Do you script your code from other apps? That would be a requirement to keep the interactive version (or some piece to avoid the GUI startup).
We usually do one or the other. But sometimes we have utils that have to be deployable through ftp and run ssh. Or we have tools that our users embed into their apps and don't want to expose a UI (data migration / conversion).
To this day, some of the most efficient user interfaces I've ever seen were plain old terminal-based character interfaces.
Anecdote: I was once part of a project to "modernize" a terminal application used by 500 customer service representatives. We published sexy GUI mockups and everyone, including the users, were suitably impressed. We worked for six months on the application, and all the user acceptance testing seemed to indicate we had a winner.
But when the application was finally launched, it failed miserably. As it turns out, CSRs are measured for performance daily, right down to the average number of seconds per call handled. And no matter how hard they tried, they could not match the same level of efficiency in the GUI as they could in the terminal interface. They could get close with tabs and shortcuts, but not quite there.
Hard lessons learned. Modern programmers may abhor "dinosaurs", but do users really care about slick interfaces? Usually they just want to get their work done.
When I first read this, my immediate thought was that this is probably one of those apps that's basically a series of forms, but displays inside a terminal. Often you see such dinosaurs running on cash registers. I also recall seeing such an app used to apply for a loan when I bought my car. This type of application doesn't seem to have a place in the modern world -- any system with even a tiny bit of processing power can handle a normal GUI nowadays. Unless you're trying to support really low-end legacy customers, get rid of this user interface. A GUI with decent keyboard shortcuts (please, please, please put some thought into keyboard-only use of your GUI programs...) is going to be equally effective for the users coming from the old CHUI system and much friendlier to those used to a GUI, without having to have 2 versions of your app.
I don't see why everyone is bringing up command line apps. I think most people recognize that the command line isn't going away. It's far faster for many tasks than a GUI, largely because the programs tend to be non-interactive (and thus easily scriptable). As soon as your app becomes interactive (or, at least, doesn't have a param to make it non-interactive), running it from the command line is much less important. Even awesome programs like Vim that are terminal-based are transitioning to their graphical counterparts (gVim) because it gives you the best of both worlds.
Even GUI apps like Firefox can benefit from command line interfaces like Ubiquity. If there's a way to provide the command line from within the GUI then why not have the best of both worlds?
A lot of CAD programs have command line interfaces that show you what the GUI interaction you just performed equates to in the command line. That way you can learn the command line operations for the things that you do frequently and where the command line can be quicker to interact with whist still having the discoverability of the GUI interface.
See this youtube video demonstrating Rhino3D's command line
CHUI is faster in execution speed, not user interaction speed. I write embedded systems (as well as GUIs), so I'll always have a use for command line apps.
Every study I have ever read showed that CHUI's are much faster for experienced users. GUI's are easier for new users and for applications that are only occasionally used. Also for a given screen size, you can display more information on a CHUI then a GUI. A good GUI can give you a quick over view at a glance.
In addition to the other benefits mentioned above, I've frequently found another reason to keep around an alternative UI--it keeps you and your interfaces honest. When an application is built with only one user interface, it becomes much easier to let design principles slide and for your business logic, etc. and your GUI to become an intertwined ball of spaghetti--despite best intentions. Regardless of the importance of your customers having a command-line interface, soon there might come a time when an alternative GUI (read: presentation layer) might be needed, and you'll want to be prepared. This might not be relevant to your requirements, but I think it's something good to keep in mind...
One of the big issues that we encountered was multisession capability which is almost nonexistent with the GUI technologies I have seen. Our users were quick to point out that with the current character based interface they could have over a dozen Telnet based terminal sessions going at the same time on their PC screen which enabled them to multitask or task switch with high efficiency. They rated multitasking as the killer feature which they benefitted from in our fast paced environment where interruptions are frequent. Being able to have concurrent access to multiple instances of a particular ERP application or multiple different ERP applications while always retaining session states was important to our user community.
I think the problem comes from design practices in GUI forms. We tend to place more objects on them especially with a vertical scroll bar and tab capabilities. This also makes loading slower. Going through CHUI menus with the keyboard is faster once you've memorized those sequences and holding the Ctrl key isn't required. There is something about the menu bar in Windows where the short-cut key descriptions are off to the right. The character based menus seemed easier to remember after awhile.
A) - This Menu
B) - That Menu
C) - Some other Menu
Or you could arrow through the choices and you just seemed to have some muscle memory where That Menu is the second choice.
As soon as you present some data, someone's going to want to query against it. You can integrate that with a gui, no problem. If you think some of your customers are going to want to script certain tasks. set it up. Anything to do with automation is better done from the command line(y harlo thar cron job!)
I love guis. I'm a mac user. But there is a time and a place for a CLI.
I was sysadmin at a university math department when the registration system went from a character based system using telnet, to a gui system on a PeopleSoft app.
The gals in the front office HATED the new system. Now part of this was the whole bit about old shoes being more comfortable. But when I asked about it, Christine said that even after a week of doing several hundred registrations per day, the new system took several times as long to do anything. Lots of things only doable with a mouse. The old system could accept input as fast as they could type. Screen repaints were under a tenth of a second. New system had lots of 3/4 to 2 second pauses -- just long enough to be annoying, not long enough to do anything else.

Put a process in a sandbox where it can do least harm

I'm looking for the concept to spawn a process such that:
it has only access to certain libraries/APIs
it cannot acess the file system or only specific parts
it can do least harm should malicious code run in it
This concept is known as sandbox or jail.
It is required to do this for each major Operating system (Windows, MacOSX and Linux) and the question is conceptual (as in what to do, which APIs to use and and what to observe) rather then language specific.
answer requirements
I really want to accept an answer and give you 20 points for that. I cannot accept my own answer, and I don't have it yet anyway. So if you really want your answer to be accepted, please observe:
The answer has to be specific and complete
With specific I mean that it is more then a pointer to some resource on the internet. It has to summarize what the resource says about the topic at least.
It may or may not contain example code, but if it does please write it in C
I cannot accept an answer that is 2/3 complete even if the 2/3 that are there are perfect.
this question FAQ
Is this homework? No.
Why do you ask this like a homework question? If you ask a specific question and you want to get a specific answer, and you know how that answer should look like, even though you don't know the answer, that's the style of question you get.
If you know how it should look like, why do you ask? 1) because I don't know all the answer 2) because on the internet there's no single place that contains all the details to this question in one place. Please also read the stackoverflow FAQ
Why is the main part of your question how to answer this question? Because nobody reads the FAQ.
Mac OS X has a sandbox facility code-named Seatbelt. The public API for it is documented in the sandbox(7), sandbox_init(3), and related manual pages. The public API is somewhat limited, but the facility itself is very powerful. While the public API only lets you choose from some pre-defined sandboxes (e.g. “All sockets-based networking is prohibited”), you can also use the more powerful underlying implementation which allows you to specify exactly what operating system resources are available via a Scheme-like language. For example, here is an excerpt of the sandbox used for portmap:
(allow process-exec (regex #"^/usr/sbin/portmap$"))
(allow file-read-data file-read-metadata (regex
#"^/etc"
#"^/usr/lib/.*\.dylib$"
#"^/var"
#"^/private/var/db/dyld/"
#"^/dev/urandom$"))
(allow file-write-data (regex
#"^/dev/dtracehelper$"))
You can see many sandboxes used by the system in /usr/share/sandbox. It is easy to experiment with sandboxes by using the sandbox-exec(1) command.
For Windows, you may want to have a look at David LeBlanc’s “Practical Sandboxing” talk given at Black Hat USA 2007. Windows has no built-in sandboxing technology per se, so the techniques described leverage an incomplete mechanism introduced with Windows 2000 called SAFER. By using restricted tokens, one can create a process that has limited access to operating system resources.
For Linux, you might investigate the complicated SELinux mechanism:
SELinux home,
a HOWTO. It is used by Red Hat, for example, to harden some system services in some of their products.
For Windows there is a sandbox in Google Chrome. You may want to investigate it. It uses liberal BSD-like license.
For Linux there would be good old chroot or more sophisticated http://plash.beasts.org/wiki/.
OS X since Leopard has some SELinux-like protection available.
The site codepad.prg has a good "About" page on how they safely allow the execution of any code snippets..
Code execution is handled by a supervisor based on geordi. The strategy is to run everything under ptrace, with many system calls disallowed or ignored. Compilers and final executables are both executed in a chroot jail, with strict resource limits. The supervisor is written in Haskell.
When your app is remote code execution, you have to expect security problems. Rather than rely on just the chroot and ptrace supervisor, I've taken some additional precautions:
The supervisor processes run on virtual machines, which are firewalled such that they are incapable of making outgoing connections.
The machines that run the virtual machines are also heavily firewalled, and restored from their source images periodically.
FreeBSD has specific concepts of jails, and Solaris has containers. Depending on what you're looking for, these may help.
chroot jails can help to limit what an application can do (though any app with root privileges can escape a jail), and they're available on most UNIXen, including OS X.
As for Windows, I'm not sure. If there was an easy way to sandbox a Windows app, most of them would be a lot more secure by now, I'm sure.
On windows (2000 and later) you can use Job objects to restrict processes.
If you really want a technique that will work with all these platforms, as opposed to a separate solution for each platform, then I think your only answer is to set up a virtual machine for each testing environment. You can restore back to a snapshot at any time.
Another big advantage of using virtualization is that you can have all of the testing environments with their guest operating systems all on the same box.
For Linux, there is AppArmor. Unfortunately, the project is somewhat on hiatus.
Another sandboxing-alternative is VServer, which uses virtualization.
Generally any virtual private server will do:
Linux VServer
http://linux-vserver.org/Welcome_to_Linux-VServer.org
Parallels Virtuozzo Containers
http://www.parallels.com/products/pvc/
and as was mentioned FreeBSD and Solaris has own implementations.
Oh. actually I've noticed you're asking it to work on ANY OS. Well, that might be complicated a bit as the I think less effort is just to reuse some VM that can support some level of sandboxing like:
Java
.NET
I'm not an expert on the topic, but i think the standard answer for linux is to define a SeLinux policy with the right capabilities for the process.

Is there anything similar to the OS X InputManager on Windows?

Is there anything similar on Windows what would achieve the same as the InputManager on OS X?
If you are looking to inject code into processes (which is what Input Managers are most commonly used for), the Windows equivalents are:
AppInit_DLLs to automatically load your DLL into new processes,
CreateRemoteThread to start a new thread in a particular existing process, and
SetWindowsHookEx to allow the capture of window events (keyboard, mouse, window creating, drawing, etc).
All of these methods require a DLL which will be injected into the remote process. C would be the best language to write such a DLL in as such a DLL needs to be quite light weight as to not bog the system down. RPC methods such as named pipes can be used to communicate to a master process should this be required.
Googling for these three APIs will turn up general sample code for these methods.
I'm pretty sure Windows has an API that developers can use to create new kinds of text input systems. I gather there are a wide variety of text input systems in use in non-Roman-derived markets, many of which are provided by third parties.
It's unclear if that's what you were really asking about, though, because you just assumed everyone knows what you would want to use an Input Manager for on Mac OS X.
If you want to create a new type of input method, ask how to do that.
If you want to get your own code running inside other applications, ask how to do that.
Don't just assume people can read your mind when asking questions, and don't assume that they have the same experience that you do and will recognize all the same platform-specific terminology.

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