I am creating a GeneXus extension and I want that on the AfterOpenKB event the extension reads a file. So, what I did was copy the files that I need read to the packages folder in GX. The thing is that when I am debugging the extension, the method AfterOpenKB is called twice and in one of those is searching for the file in the KB's folder.
The question is, it's expected that the method trigger twice or am I doing something wrong? Should I copy the file to the KB's folder too?
Thanks!
The AfterOpenKB event should be fired only once every time a process opens a KB. Is your extension a UI or a BL extension? I suspect you're developing a BL extension, and what you're seeing is that the MSBuild process for the specifier, which is an independent process and also starts the GX BL, triggers the AfterOpenKB event when opening the same KB as the GX process is opening.
Can't give an answer to if you should copy the files to the KB folder, without knowing exactly what the extension is doing, but in general, don't believe is a good practice to copy files to the GX installation when opening a KB. Note that it'll be fairly common that GX is located inside Program Files, and writing files into that path will require elevated privileges. Currently GX requires to run as an elevated process, but that's something we may like to change in the future, so I heavily suggest against depending on that. The KB folder seems a better place to copy the files, but again, can't tell for sure without knowing exactly what the extension is doing and what are the files for.
Hope that helps.
Related
So the images below were originally a vb files. I have just opened it and it looks like this and the compiler won't run it. I am unsure whether this is a compiler error or whether it may have become corrupt because the project is stored on an external drive. It is just these two forms that have broken like this; I have one other form and a module in the same project that are okay but the project can't run because of the two that are broke.
Broken Login Form
Broken Diary Form
If it changes anything, the designer files for the forms are intact it is just the scripting for the forms elements that is broken.
Also, if I can't identify the cause, is there a way to revert it back to the last working version in visual studio to get my code back? Just because I put a lot of time into it.
The data in those files is most likely gone.
IMPORTANT: Do not write anything to that disk drive unless you find that you cannot recover those files.
If you are using a version control system then you can revert to an earlier version.
If you are using Windows 10 and you happen to have stored those files in a location included in what File History saves, you can recover them from that.
If you use some other form of backup, retrieve the files from that.
If you have a separate disk drive with at least as much free space as the one with the corrupted files, you could try running file recovery software as it might be that the zeroed-out file was written to a different place on the HDD.
TinTnMn pointed out in a comment that if you previously compiled the code, you should have executable files in the "obj" and "bin" folders that can be decompiled to recover most of your work
It could be quicker to re-write the code while it is still fresh in your mind.
In the system32 directory I saw an .OCX file with a corresponding .OCA file.
I had thought .OCA files are used only by Visual Basic. Are they therefore unnecessary for program execution and could be removed?
If they are unnecessary, why would there be an .OCA in the system32 folder in the first place?
.OCA files serve as a cache of the extended type library information for its corresponding .OCX file.
If you delete an .OCA file for a control VB recognizes and uses, VB will recreate the .OCA file when you load a project requiring the control. The recreation process takes a little time but comes with no penalty otherwise.
Last reviewed: April 4, 1996
Article ID: Q149429
SUMMARY For every custom control file (.OCX) that Visual Basic uses,
there is an accompanying .OCA file of the same file name. For example,
GRAPH16.OCX has an accompanying .OCA file called GRAPH16.OCA. An .OCA
file is a binary file that functions as both an extended type library
file and a cache for the custom control file.
MORE INFORMATION
A type library is a file or component within another
file that contains OLE Automation standard descriptions of exposed
objects, properties, and methods. The actual working type library for
a custom control used in Visual Basic is a combination of the type
library of the control itself and the additional properties provided
by the framework that wrap the control.
Some of the properties of the control are provided by the framework
and some by the control itself. Programmatically, the properties from
the framework and the control all appear as properties of the control.
In order for these properties to appear, Visual Basic creates an
extended type library when the control is loaded into the toolbox.
Because the process of reading the control's type library and creating
the extended type library is time consuming, Visual Basic caches the
extended type library information into an OCA file.
If you delete the OCA file for a control Visual Basic recognized,
Visual Basic will re-create the .OCA file when you load a project
requiring the control. This re-creation process comes with a time
penalty.
(http://support.microsoft.com/kb/149429)
So, don't worry about including them when you deploy your application.
Sorry to resurrect a zombie thread, but I want to summarize to make sure I understand this.
An OCA file is only needed during compilation of a program and if it is missing, VB will create what it needs so all that is lost is time during compiling. Unless you have really sloppy programming and another homemade dll or ocx needs a particular oca.
If an oca is shipped with a product, it should be able to be safely deleted.
No, they are not necessary for it to execute but they are necessary for the program to run properly (if the program required the file in the first place).
They never need to be deployed with a finished program for it to run.
This could be a dumb attempt to answer, but you could simply rename the file and see if the application quits working. If so, those files are necessairy.
DNA-science is about the same:
Remove a gene and see what stopped "working". De facto, this gene is related to / necessairy for that body-part or whatever.
Re: No, they are not necessary for it to execute but they are necessary for the program to run properly (if the program required the file in the first place).
Since execute and run mean the same thing - what you are saying is that:
it's not required for it to run but it's required for it to run properly??
or alternately
it's not required for it to execute but it's required for it to execute properly??
I am suspecting that the *.OCA files are not required EXCEPT for compiling a program using VB and if they don't exist when you load a project then VB will create any missing OCA files automatically in order to speed up future load or compile operations in VB.
I just deleted EVERY OCA file off my system (I'm a brave man when I'm using a cloned virtual machine to do this).
I then rebooted and ran my software and it worked just fine without ANY OCA files on my entire system. Now it might take a bit longer to load/compile my programs next time as vb will regenerate the OCA files but I'm using an i7 with 16Gb of RAM and an SSD so who cares!
My windows co-workers were asking me if I could modify my non-windows binary files such that when their "Properties" are examined under Windows, they could see a "Version" tab like that which would show for a Visual Studio compiled exe.
Specifically, I have some gzipped binary files and was wondering if I could modify them to satisfy this demand. If there's a better way, that would be fine, too.
Is there a way I could make my binaries appear to be exe files?
I tried simply appending the VS_VERSION_INFO block from notepad.exe to the end of one of my binaries in the hope that Windows scans for the block, but it didn't work.
I tried editing the other information regarding Author, Subject, Revision, etc. That doesn't modify the file, it just creates another data fork(what's the windows term?) for the file in NTFS.
It is not supported by windows, since each file type has their own file format. But that doesn't mean you can't accomplish it. The resources stored inside dlls and exes are part of the file format.
Display to the user:
If you wanted this information to be displayed to the user, this would probably be best accomplished with using a property page shell extension. You would create a similar looking page, but it wouldn't be using the exact same page. There is a really good multi part tutorial on shell extensions, including property pages starting with that link.
Where to actually store the resource:
Instead of appending a block to the file, you could store the resource into a separate alternate data stream on the same file. This would leave the original file stream non corrupted on disk and not cause its primary file size to change.
Alternate data streams allow more than one data stream to be associated with a filename. Each stream is identified by a colon : at the end of the filename and an identifier.
You can create them for example by doing:
notepad test.txt:adsname1
notepad test.txt:adsname2
notepad test.txt
Getting the normal Win32 APIs working:
If you wanted the normal API to work, you'd have to intercept the Win32 APIs: LoadLibraryEx, FindResource, LoadResource and LockResource. This is probably not worth the trouble though since you are already creating your own property page.
Can't think of any way to do this short of a shell extension. The approach I've taken in the past is a separate "census" program that knows how to read version information from any kind of file.
Zip files can be converted into exe files by using a program that turns a zip file into a self-extracting zip (I know that WinZip does this, there are most likely free utilities for this also; here's one that came up on a search but I haven't actually tried it). Once you've got an exe, you should be able to use a tool like Resource Hacker to change the version information.
It won't work. Either Windows would have to know every file format or no file format would be disturbed if version information were appended to it.
No, resource section is only expected inside PE (portable executable; exe, dll, sys).
It is more then just putting the data inside the file, you have a table that points to the data in the file header.
What you can do if you have NTFS drive, is to use NTFS stream to store custom properties this way the contact of the binary file will remain the same, but you will need to use a custom shell extension to show the content of the stream.
Our issue is that our project has files being downloaded using wget to the file system. We are using ruby to read the downloaded files for data.
How is it possible to tell if the file is completely downloaded so we don't read a half complete file?
I asked a very similar question and got some good answers... in summary, use some combination of one or more of the following:
download the file to a holding area and finally copy to your input directory;
use a marker file, created once the download completes, to signal readiness;
poll the file twice and see if its size has stopped increasing;
check the file's permissions (some download processes block reads during download);
use another method like in-thread download by the Ruby process.
To quote Martin Cowie, "This is a middleware problem as old as the hills"...
The typical approach to this is to download the file to a temporary location and when finished 'move' it to the final destination for processing.
I have a Windows service application on Vista SP1 and I've found that users are renaming its executable file (while it's running) and then rebooting, thus causing it to fail to start on next bootup because the service manager can no longer find the exe file since it's been renamed.
I seem to recall that with older versions of Windows you couldn't do this because the OS placed a lock on the file. Even with Vista SP1 I still cannot copy over the existing file when it's running - Windows reports that the file is in use - makes sense. So why should I be allowed to rename it? What happens if Windows needs to page in a new code page from the exe but the file has been renamed since it was started? I ran Process Monitor while renaming the exe file, etc, but Process Mon didn't report anything strange and just logged changing the filename like any other file.
Does anyone know what's going on here behind the scenes? It's seem counter intuitive that Windows would allow a running process' filename (or its dependent DLLs) to be changed. What am I missing here?
your concept is wrong ... the filename is not the center of the file-io universe ... the handle to the open file is. the file is not moved to a different section of disk when you rename it, it's still in the same place and the part of the disk the internal data structure for the open file is still pointing to the same place. bottom line is that your observations are correct. you can rename a running program without causing problems. you can create a new file with the same name as the running program once you've renamed it. this is actually useful behavior if you want to update software while the software is running.
As long as the file is still there, Windows can still read from it - it's the underlying file that matters, not its name.
I can happily rename running executables on my XP machine.
The OS keeps an open handle to the .exe file,. Renaming the file simply changes some filesystem metadata about the file, without invalidating open handles. So when the OS goes to page in more code, it just uses the file handle it already has open.
Replacing the file (writing over its contents) is another matter entirely, and I'm guessing the OS opens with the FILE_SHARE_WRITE flag unset, so no other processes can write to the .exe file.
Might be a stupid question but, why do users have access to rename the file if they are not suppose to rename the file? But yeah, it's allowed because, as the good answers point out, the open handle to the file isn't lost until the application exits. And there are some uses for it as well, even though I'm not convinced updating an application by renaming its file is a good practice.
You might consider having your service listen to changes to the directory that your service is installed in. If it detects a rename, then it could rename itself back to what it's supposed to be.
There are two aspects to the notion of file here:
The data on the disk - that's the actual file.
The file-name (could be several or none) which you can give that data - called directory entries.
What you are renaming is the directory entry, which still references the same data. Windows doesn't care about your doing so, as it still can access the data when it needs to. The running process is mapped to the data, not the name.