In my C# code I want to be able to use some Shadow Copy mechanism in order to copy files that are being used by another process.
I've seen that solutions exist on the web, in enterprise or command line tools. But could it be done programmatically in order to mimic a simple file copy?
It appears that alphavss does what you want. The sample file VssBackup.cs here seems to do exactly what you want.
This class encapsulates some simple VSS logic. Its goal is to allow a user to backup a single file from a shadow copy (presumably because that file is otherwise unavailable on its home volume).
Related
this is more of a question because I am experimenting with this.
All over the internet I see how you can update a .txt file. Well that is all good and well, but lets say I have a .doxc or even an .exe or even a .dll file.
If we make a minor change to a file, do we really have to replace(overwrite) the whole file?
Is it possible to "update" the file so that we don't use too mush data (over the internet).
What I am trying to achieve is to create a FTP client with a FileSystemWatcher. This will monitor a certain folder on the Computer. If anything changes in this folder (even sub directories) then it uploads, deletes, renames, or changes the file. But at the moment I am wondering if I have, lets say, a 20MB .exe file or whatever, if it is possible to change something in that .exe, instead of just overwriting the whole thing... thus, sparing some cap.
In general, it's possible to update the remote file only partially, but not in your case.
What would work:
1) track the file change using a filesystem filter driver, which gives you information about what parts of the file have been updated.
2) use the protocol which allows partial upload or remote modification of the file (eg. SFTP).
As for your scenario:
Step 1 is not possible with FileSystemWatcher.
Step 2 is not possible with FTP protocol which doesn't support modification of file blocks.
Since your are experimenting, I can provide some pointers. But I dont know for sure if the below operations are just updates or replaced newly by the underlysing os calls
Have different cases for each file type. Try with a basic types first, a txt file, then a binary file etc.
You should have the entire copy of the current file somewhere, sine you "should" compare the old file to know what changes
Then when a change is made to the file compare it with the old file e.g) in a text file with 1 MB and the change is only 1 KB you will need to build a format like
[Text][Offset][[operation]
e.g) [Mrs.Y][40][Delete] then [Mr.X][40][Add]
Then your ftp client should be able to implement this format and make changes to the local copy on the client.
No it is not possible to only upload the changes to .exe file.we have to overwrite it.
#Frederik - It would be possible if FTP supports an updating of resource like HTTP's PUT command. Try exploring that angle. Let us know if you find something.
I was always pretty impressed by those programs that you could install by executing one installer file, which would then extract all the other required files to run the actual program.
And even now im still wondering how you would code a program that extracts files that are literally still inside the program ( so not in some kind of zip) , i've seen tons of installers for games who have this. I need this cause I want to extract a file on the right moment without giving the person who uses the program the ability to delete the file before its extracted, this may seem vague, but I hope i've informed you enough.
I'm just going to say that building an installer is difficult.
I'd recommend using NSIS: http://nsis.sourceforge.net/Main_Page
As for creating a file the user can't access, create a temp file with the correct read/write permissions, extract the data to the temp file, then copy the file where it needs to go.
Extract happens without the user interfering, and copy protection is handled by the OS.
What about changing the build action for the file you want to hide to Embedded Resource, or something like that that compiles the file inside the dll/exe?
Executable program is just file, So you can append any data at you executables. (works for my c++ compiled program)
$ cat executables some_blob_data > new_executables
Since argv[0] of main() is name of your file, you can use this to acess data in this file itself (works for c or c++ and likley for other languages to)
A really simple way to do this is to use your archive tool or one of the dozens of already made installers. WinRar, WinZip and most others allow the creation of self extracting exe files. I know you've said that is not what you want but if you make sure to make it auto exec your installer app and remove all of the temporary files when you're done it really can be very fool proof and professional looking. Obviously, the various installer applications are able to do what you're wanting.
If you really want to do this yourself the easy solution is going to most likely be dependant on your IDE software and language. The generic answer is that you'll need a compression library which can accept a stream as input. Then you'll want to make your actual files into resources inside your installer app. At that point it's just a matter of telling the compression library to read from a stream which is pointed at the resource. How that is done varies greatly from language to language.
I would like to know how Windows generate folder, where will be ClickOnce application installed.
In Startmenu is "shortcut" to file, what is putted in some "startrek" folder like:
C:\Users\USERNAME\AppData\Local\Apps\2.0\GT??4KXX.PRJ\EGV???1G.??C\prin..tion_7???5a2?????74b6_0000.0002_1dae????89111c35
What does those folder names mean?
For example:
If i will have for example some settings.txt file where i want that user can change some parameters of the application. Is there way how to know, WHERE it will be installed and WHERE the file is? (Where user will find this settings.txt file).
I know that i can create the file for example in C:\ and after start the application i will modify the file in "strong" path. But i dont really like too much files, folders, whatever in C:\ and i prefer to have settings files in same folder like the application. But with ClickOnce installations is it really hard - impossible - to find that file.
It seems like when the "startrek" is something like hash of the project.
So i would like to know what does the folder means and if its some hash of the project or what is that.
To find the folder that contains your executable, you can use the Assembly.Location property.
For example:
string exeFolder = System.Reflection.Assembly.GetExecutingAssembly().Location;
However, if you want to store settings for your ClickOnce app, you shouldn't do it by writing a file to the .exe's folder.
Instead, you should use Microsoft's Application Settings support. Doing it any other way is going to be a lot of extra hassle, and Microsoft's support is very good. It does need half an hour to read through the documentation, but it's far and away the best thing to do, IMHO.
(I'm assuming that you only need the settings to be stored on the local PC for the same user to use later. If you want the settings to follow the user around (i.e. roaming settings), you can't use the Microsoft support.)
If you have more complex settings that you want to store in a file that you create directly, you should consider using the isolated storage that the answer from JRoughan mentions.
From inside the ClickOnce app you can find the default directory where files are stored using
ApplicationDeployment.CurrentDeployment.DataDirectory
Or you can use isolated storage and choose whether you want to save per application or per user.
I don't think it's possible to determine these folders from outside the app itself. If you need a known location you'll have to hard-code it.
Update
I also don't believe it's possible to infer what the install directory will be for an app. It would be unwise to use even if possible as updates to the app will not be in the same location.
If you have data that the user is modifying through your program, you will be happier if you don't leave it in the ClickOnce program directory. You can get completely messed up when there's an update. Check out this article about what to do with your data to keep it safe and be able to find it. It talks about putting it in LocalApplicationData, but if you want your user to be able to find it and edit it, just put it in MyDocuments/yourappname/settings or something like that.
I wouldn't use Isolated Storage; there are reported problems with that and ClickOnce.
I'm writing a program that needs to access a file inside of c:\program files\program_name\.
My target file will always be inside of \program_name\program_name\bin\something.exe
However, because the program is extracted from an archive, if the user unpacks it improperly, it'll be simply \program_name\bin\something.exe, skipping a whole level.
Currently I'm basically getting the contents of c:\program files\, collecting the names of all folders that contain program_name, then adding them to the list and then using the list to loop through each one of those seeing if there's a program_name inside of it, etc, which should eventually lead me to the result.
Basically I'm creating large chunks of code for each individual possibility. Is there a smarter way to go about this?
Sounds like you could benefit from having an installer that writes to the registry. Then you'll know where all the files and folders are, even if the user installs to a weird location.
To expand on what Charlie said -- you could wrap the original app in some kind of unified installer type thing that would write the registry and extract the app to whatever place the user decides. The installer would prompt the user for the location to install to, and would extract to that location. InnoSetup can be configured to write the uninstall info, put uninstall links, etc. You can customize the uninstaller part of the InnoSetup script to do whatever cleanup you need, and/or call other external programs, if necessary.
InnoSetup allows you to package stuff in the actual installer exe, so you only have to distribute one flle. I can verify that this works -- although I've never tried it for packing huge files.
Here's a link to InnoSetup: http://www.jrsoftware.org/isinfo.php
I am making a data backup program. I need to copy files from one folder to another, while some files are still being used by a running process. It's OK when the running process shares file access. But I will get exception if files are not shared. (FileShare.None)
I am wondering if there is any way to read a non-shared file in C#.
Thanks,
C# under the hood uses the file access operations your operating system provides, including its file sharing behavior. So I'm afraid C# cannot go beyond this.
There is a technique if you are using Vista or later. You can use the Volume Shadow Copy feature. However, getting to work in C# will be tedious, and all that I can provide for help are references. However, if you wanted to administrate a solution instead of developing one, you could use Windows Backup to copy the files on a schedule.
Links:
Shadow Copy Explained
Shadow Copy SDK
Video Presentation on Shadow Copy