I have a legacy 32-bit application written in Borland's C++ Builder. I need to show specific pages from within a HtmlHelp file programmatically. Until now I've been doing this via HtmlHelp.ocx, but this does not work on x64 versions of Windows Vista / Windows7 as described in this thread.
I can't compile the application as 64-bit executable. Therefore the only workaround I have found so far is to create a 32-bit component implementing a COM object which loads and calls into the 32-bit DLL, and exposes the 32-bit DLL interface as a COM interface.
That sounds far too complicated just to display a chml file with a specific topic. There must be something else. But what is it?
Isn't this possible via the htmlhelp api ? (htmlhelp.h in the MS sdk?)
Specifically htmlhelpA function with HH_DISPLAY_TOPIC
Some people prefered going via the .OCX in the past because it was more reliable on IIRC w9x, but I assume that is not a problem in a 64-bit application.
It could be that these functions also list to some ocx/dll not there in 64-bit land, but it is worth a try. I can't easily check this.
Related
Well, I wrote a code for File I/O with Win32 API.
(I'm using Visual studio 2013)
It just gets two file name(one for source, one for destination) and duplicate one to another.
I used CreateFile, ReadFile, WriteFile.
It's functionally simple. It's not problem. But..
I wanna SEE the system call in these function being called in debugger.
How can I do this?
with Call stack? Disassembler?
So you want to be able to debug not only your own code but also the API itself.
There are different ways to do that.
At the simplest level, just use the debugger from VS2013. You won't be able to trace into kernel code, but all the user level code in the API. But of course as you will use a non debug version of Windows with no symbol table you will only see low-level machine code (*).
If you really want to go deeper, you will have to use the Debugging Tools for Windows. As you say you want to debug system calls, my advice would be to use the Windows Driver Kit, the Windows Symbols, and if you really go down to kernel mode the Windows Remote Debugging Client for Windows (all those tools are available from Windows Dev Center).
All those tools integrate nicely in VisualStudio, but be prepared to hard low level work :-)
(*) You can also use the Microsof Symbol Server to access windows symbolic information - thanks to IInspectable for his comment. But I've never tested.
I need to create a web-controlled application (that lives in the browser) that can connect to and read data from devices connected via USB or the serial port.
At the moment, I'm using an ActiveX control to do this. However, I'm like to re-write this system to make it cross-browser (support Firefox) and eventually cross-platform (support Safari on Mac). ActiveX is neither cross-browser or cross-platform, so I'm looking for an alternative technology.
My first inclination would have been to use Silverlight, because Silverlight 4 grants access to COM Automation. Unfortunately, this only works with OOB (Out of browser) Silverlight applications - in-browser systems are still bound in a sandbox and do not have access.
So, what technologies exist (frameworks, browser plug-ins, etc) that will allow me to interface with a USB/Serial device from within a browser-based web application? What are the pros/cons of each?
I think your best bet is probably Java in this case. USB, though an industry standard in terms of protocol is definitely not standardised in terms of bare-metal implementation. For this reason, you will still need a different Java USB implementation for each distinct platform (windows, linux, osx, bsd) that you intend to support. Of course you will also have to pay for code-signing certificates so you can try to convince people to grant your application the kind of access it requires; something that browsers try very hard to deny access to and most people in this day and age are very unwilling to grant. That said, there's an old IBM article here on the various Java USB projects that makes a good read. Good luck.
http://www.ibm.com/developerworks/library/j-usb.html
-Oisin
It might be painful, but you could use a signed Java applet. Signed Java applets can have full access to the user's system.
Java does not have built in USB support, so you would probably need to roll your own JNI interface to native USB APIs.
Using JNI in an applet can be tricky. I've done it before. If you Google the topic, most results say "don't do it" or "you can't do it." Well, you can do it.
This is how I did: I packaged the native libraries (DLL, so, etc) inside the applet's JAR, and then read the native libraries out of the JAR using e.g. getResourceAsStream. I then wrote the libraries out to an appropriate location on disk (e.g. ${user.home}/.myapp/.) I then used System.load to load the JNI DLL.
There can be some ClassLoader issues with JNI libraries and applets. The issues are subtle and difficult to explain. They basically have to do with the fact that a JVM can only load and bind a given JNI library once per VM instance, but applets get instantiated a lot, often with their own new ClassLoader, which can be problematic. The work that Sun did on process separation in the Next Generation Browser Plugin may have relieved some of these issues, but your users will only have this if they are using Java 1.6.0_10 or later.
It is also possible to use JNA within a signed applet. I would not recommend using JNA to access USB APIs directly. But JNA can sometimes be a big time saver for accessing simple native functions. Although once you've set up your JNI infrastructure, JNA probably has less value.
Here are a few other random thoughts:
Java WebStart - Can be launched from browser, but runs outside the browser
Microsoft ClickOnce - Can be launched from browser, but runs outside the browser
Flash / AIR - Can't escape its sandbox
The best solution I've come across thus far is the cross-browser/cross-platform plug-in system called FireBreath. This is a framework built in C++ that allows you to generate plug-ins for both ActiveX and NPAPI from the same codebase.
So build it once, make it work, and it compiles to one DLL that you can deploy in either environment: ActiveX for IE, NPAPI for everyone else.
I am looking for suggestions on how to, on Windows, execute a windows form and/or WPF application, and force it's display to always be shown within the grahpic context of another completely separate process (basically as if the "child" process were simply another form control).
As a little bit of background, we have a legacy 32 bit application that we have inherited, of which relies upon quite a few third party libraries that are not offered by their respective suppliers as 64 bit assemblies. Our task is to augment this legacy application, which by itself has very little to no need for a 64 bit address space, with new functionality that requires more memory than any 32 bit process is able to provide.
As far as I know, we will need to support everything from windows xp x64 -> windows 2008r2/win7 x64.
I'm completely open to any suggestions, and appreciate very much everyone's input that respond!
I'm not aware of any techniques for achieving what you ask for - my recommendation would be to instead keep all of your UI in the 32 bit address space, and use inter-process communication to offload the memory intensive parts of your application into a separate process instead.
A possibility is to use 'Windows Hooking." It's pretty wild stuff.
http://www.hook-api.com/
Search for those terms and you'll find some interesting stuff.
General explanation of hooking.
http://en.wikipedia.org/wiki/Hooking
Another possibility is to use a third-party program like Citrix that can run non-Windows programs in a Windows window/environment. Perhaps getting that to run as a control in a Widnows app. I understand it's an old Win32 app, but in this case one could consider the old app "non-windows."
HTH
I looked at some other questions on SO and its not clear if c is built on top of, under, or alongside the WINAPI. Like for example could someone write something in pure c that was able to open a window, or would they need to use the windows api?
I noticed similarities between the c (library?) version of opening a file (fopen) vs the windows API version (CreateFile) which makes me wonder if one is just a wrapper for the other. Does anyone know?
If windows is running; is a programmer forced to program using the windows api to get something running on it or can the programmer not use the windows api at all and directly access the hardware (ie. does the windows operating system protect access to the hardware)?
Which is more portable between different versions of windows of windows ce. The documentation I found (which has now changed) used to say that CreateFile only goes back to version 2.0 of windows ce (here: http://msdn.microsoft.com/en-us/library/ms959950.aspx -
Notice the note on the link at the very bottom that shows the supported version information has been changed). So what is one supposed to use for windows ce version 1? In other words is programming using c functions or the functions labeled WINAPI more likely to work on all versions of windows CE?
I read the following in a book about programming windows ce and it confused me, so all of the above questions can be understood better in context of making sense of the following:
Windows CE supports the most of the same file I/O functions found on Windows NT and Windows 98. The same Win32 API calls, such as CreateFile, ReadFile, WriteFile and CloseFile, are all supported. A Windows CE programmer must be aware of a few differences, however. First of all, the standard C file I/O functions, such as fopen, fread, and fprintf, aren't supported under Windows CE. Likewise, the old Win16 standards, _lread, _lwrite, and _llseek, aren't supported. This isn't really a huge problem because all of these functions can easily be implemented by wrapping the Windows CE file functions with a small amount of code.
My understanding of wrapping is that you have to have something to wrap, given how it appears that win16 and c library are not available is he stating to wrap the CreateFile function to make your own c-like version of fopen? (The only other thing I am aware of is assembly, and if that is what he was suggesting to wrap it wouldn't be written in such a casual manner.)
Given the above, what is the dependency relationship between c language (syntax, data structures, flow control), the c function library (ex. fopen), and the windows api (ex. CreateFile)?
C existed long before Windows did. The Windows API is a bunch of libraries written in C. It may or may not be possible to duplicate its functionality yourself, depending on what Microsoft has documented or made available through the API. At some level it is likely that fopen() and CreateFile() each call the same or a similar operating system service, but it's unlikely that one is a strict wrapper for the other. It would probably be difficult to bypass the Windows API to access the hardware directly, but anything is possible given enough time and programming effort.
C doesn't know anything about GUIs, and VERY little about operating systems at all. Anything you do graphics-wise in C is through the use of libraries, of which the win32 api is an example.
The windows API is implemented in the C programming language. Functionality provided by the C standard libraries, such as fopen, is portable because it is compiled down to the appropriate assembly code for different architectures by different compilers. Windows API functions such as CreateFile only work on machines running Windows and are therefore not portable.
In theory it's possible to write C that talks directly to the hardware. Back in the days of MS-DOS (for one example) quite a few of us did on a fairly regular basis (since MS-DOS simply didn't provide what we needed). Edit: On some small embedded systems, it's still quite commonplace, but on typical desktop systems and such this has mostly disappeared.
Two things have changed. First, modern systems such as Linux and Windows are much more complete, so there's a lot less need to deal directly with the hardware. Second, most systems now run in protected mode, so normal user code can't talk directly to the hardware -- it has to go through some sort of device driver.
Yes, most of the C library uses the underlying OS so (for example) on Windows, fopen and fwrite will eventually call CreateFile and WriteFile, but on Linux they'll eventually call open and write instead.
I noticed similarities between the c (library?) version of opening a file (fopen) vs the windows API version (CreateFile)
Not surprising. They do similar things.
[is] one is just a wrapper for the other? Does anyone know?
You can't find out because the source code is owned and kept as a trade secret.
It doesn't matter which is more "fundamental". You use the windows API from a windows program. You use C API's from C programs.
Notice that it doesn't matter. You can use C API's or Windows API's intermixed.
If windows is running; is someone forced to use the windows api to get something running on it or can they bypass windows entirely and directly access the hardware?
"Directly access the hardware"? What does that mean? If windows is running, then.... well... Windows is running. Windows mediates your access to the hardware.
Use bootcamp or GRUB or some other bootloader to bypass Windows and have "direct access to the hardware".
If they can, is it possible to damage the hardware if you don't know what your doing?
What does this mean? Are you asking if you can "damage" some rotating media (i.e., disks) by misusing their drivers? You can corrupt your hard disk no matter what OS you're running or not running. A privileged account and dumb software can write bad data on a disk. Does that count as "damage"?
Which is more portable?
What does that mean? To another Windows computer? To a computer not running Windows? What are you asking about? Please clarify your question to define what you mean by "portable".
between different versions of windows
Since different Windows are mutually incompatible, I generally suggest using only the POSIX standard libraries and avoiding all Windows API's.
However, some Windows variants (e.g. Windows mobile for phone vs. Windows "Server") are essentially totally incompatible. There is very little reason for any piece of software to run on both OS's. Portability doesn't much matter. Why try to run a phone app on a server?
Edit
So theres the c language on the bottom (closest to the hardware), then the windows API next, then the C library on top of the Windows API?
This doesn't make sense. You're mixing up two unrelated things. The "language" and the "libraries" have little to do with each other.
Also, the API is not the operating system. So by using Windows "API" all the time, you're making this more confusing than it needs to be.
Here's a way to look at this.
The Windows Operating System has several API's. There are underlying function libraries that are not part of the application interface. They're "internal".
It has a native Windows API. Callable from C.
It has a POSIX API. Callable from C. In some cases, the Posix API generally uses the Windows API.
Most operating systems, including Windows are written in C (and or assembler). The Library is then modified for each operating system to do the basic stuff. (Sockets, Files, Memory, etc ...).
The WINAPI is just a bunch of libraries (written in C and/or Assembler) that allow access to functionality within the OS.
It is not Windows related, after you changed your question, I think what you are trying to understand is the bootstrapping of an OS (Windows or other).
The book Operating Systems Design and implementation discusses the implementation of Minix (Which Linux is based on).
the WINAPI provides an interface that developers in C can use in order to use the WINAPI functionality. C++ programs can also use it.
Operating systems such as Windows contain WINAPI libraries that provide access to some operating system functionality and sometimes contact with Hardware, these libraries are written in C
Carl Norum pointed out that C existed long before Windows, but don't forget that the Windows API kind of started with the MS-DOS API, which kind of started with the CP/M API. C only existed a short time before CP/M.
Lots of answers seem to imply that the Windows API is built on C, but that seems doubtful too. __stdcall is a synonym for PASCAL, which was a keyword in Microsoft's C compilers because the Windows API was built on Pascal. __cdecl is the default for function calls in C and C++ programs compiled by Visual Studio but it doesn't work on calls to APIs.
The relationship between C and the Windows API is that they are capable of working with each other.
As a fun note, you can really get a handle on the 'power' of the Windows API by taking a look at AutoIt http://www.autoitscript.com/autoit3/. AutoIt is a great little scripting language that can create GUIs, run command line apps, manipulate windows and processes, etc. Yes, it does File I/O and networking.
What things should be kept most in mind when writing cross-platform applications in C? Targeted platforms: 32-bit Intel based PC, Mac, and Linux. I'm especially looking for the type of versatility that Jungle Disk has in their USB desktop edition ( http://www.jungledisk.com/desktop/download.aspx )
What are tips and "gotchas" for this type of development?
I maintained for a number of years an ANSI C networking library that was ported to close to 30 different OS's and compilers. The library didn't have any GUI components, which made it easier. We ended up abstracting out into dedicated source files any routine that was not consistent across platforms, and used #defines where appropriate in those source files. This kept the code that was adjusted per platform isolated away from the main business logic of the library. We also made extensive use of typedefs and our own dedicated types so that we could easily change them per platform if needed. This made the port to 64-bit platforms fairly easy.
If you are looking to have GUI components, I would suggest looking at GUI toolkits such as WxWindows or Qt (which are both C++ libraries).
Try to avoid platform-dependent #ifdefs, as they tend to grow exponentially when you add new platforms. Instead, try to organize your source files as a tree with platform-independent code at the root, and platform-dependent code on the "leaves". There is a nice book on the subject, Multi-Platform Code Management. Sample code in it may look obsolete, but ideas described in the book are still brilliantly vital.
Further to Kyle's answer, I would strongly recommend against trying to use the Posix subsystem in Windows. It's implemented to an absolute bare minimum level such that Microsoft can claim "Posix support" on a feature sheet tick box. Perhaps somebody out there actually uses it, but I've never encountered it in real life.
One can certainly write cross-platform C code, you just have to be aware of the differences between platforms, and test, test, test. Unit tests and a CI (continuous integration) solution will go a long way toward making sure your program works across all your target platforms.
A good approach is to isolate the system-dependent stuff in one or a few modules at most. Provide a system-independent interface from that module. Then build everything else on top of that module, so it doesn't depend on the system you're compiling for.
XVT have a cross platform GUI C API which is mature 15+ years and sits on top of the native windowing toollkits. See WWW.XVT.COM.
They support at least LINUX, Windows, and MAC.
Try to write as much as you can with POSIX. Mac and Linux support POSIX natively and Windows has a system that can run it (as far as I know - I've never actually used it). If your app is graphical, both Mac and Linux support X11 libraries (Linux natively, Mac through X11.app) and there are numerous ways of getting X11 apps to run on Windows.
However, if you're looking for true multi-platform deployment, you should probably switch to a language like Java or Python that's capable of running the same program on multiple systems with little or no change.
Edit: I just downloaded the application and looked at the files. It does appear to have binaries for all 3 platforms in one directory. If your concern is in how to write apps that can be moved from machine to machine without losing settings, you should probably write all your configuration to a file in the same directory as the executable and not touch the Windows registry or create any dot directories in the home folder of the user that's running the program on Linux or Mac. And as far as creating a cross-distribution Linux binary, 32-bit POSIX/X11 would probably be the safest bet. I'm not sure what JungleDisk uses as I'm currently on a Mac.
There do exist quite few portable libraries just examples I've worked within the past
1) glib and gtk+
2) libcurl
3) libapr
Those cover nearly every platform and so they are extremly useful tool.
Posix is fine on Unices but well I doubt it's that great on windows, besides we do not have any stuff for portable GUIs there.
I also second the recommendation to separate code for different platforms into different modules/trees instead of ifdefs.
Also I recommend to check beforehand what are the differences in you platforms and how you could abstract them. E.g. this is some OS related stuff (e.g. the annoying CR,CRLF,LF in text files), or hardware stuff. E.g. the previous mentioned posix compability doesnt stop you from
int c;
fread(&c, sizeof(int), 1, file);
But on different hardware platforms the internal memory layout can be complete different (endianess), forcing you to use conversion functions on some of the target platforms.
You can use NAppGUI for both console and desktop apps. The SDK uses ANSI-C and your code will work on Windows/macOS/Linux.
https://www.nappgui.com
It's free and OpenSource.