Using Struts 2: when will the .tmp file - that gets created after uploading a file - be deleted?
How can you customize when the .tmp file should be deleted? Do you have to create a copy of it?
Please don't be shy to give some code :)
1. This depends on which version of S2 you're talking about.
S2.2.1 and prior: the file upload interceptor deleted temp files.
S2.2.3 and above: the filter dispatchers start the deletion process, changed due to WW-3490.
2. Assuming you're using a recent version, it might be possible to inject a tweaked Dispatcher, although it's not immediately obvious how–if it is, that's the easiest change at the core level.
The easiest approach from a practical standpoint is to copy files in the action, which is also pretty fast on any reasonable file system.
Related
I have a project, hosted on launchpad, which contains a fairly user-specific configuration file.
Once the project is initially checked out, obviously this .cfg file should also be downloaded. However, further updates (via "bzr update") would ideally not alter this .cfg file, as the user would have made their own edits to it. These edits would be overridden / merged should (with potential conflicts) I push an update using the code with my own .cfg file - I don't want this to happen!
What's the best practice to avoid this? I can't really "bzr ignore", as then any future users checking out via bzr would then not have the .cfg file.
I could, of course, replace my .cfg file with the "stock" one each time I do a commit, but this seems a bit clunky.
Or equivalently clunky, supply the .cfg file separately.
What I'm looking for is a "single-shot" download, but never update subsequently.
Any advice?
This is a tricky problem, because version control systems in general are not engineered to have the fine-grained commit strategies needed for this approach. If you were operating in a controlled environment, you could use plugins or hooks to exclude certain files from commits etc., but that doesn't seem to be an option here. I'll add that bzr ignore won't help you, either, because it only prevents files from being added; it doesn't prevent commits or checkout of those files.
What you can do is generate the config file during build/setup/installation if it doesn't already exist. Something like:
#!/bin/sh
if [ ! -e configuration.cfg ]; then
cp etc/configuration.cfg.in configuration.cfg
fi
Here, you'd check in etc/configuration.cfg.in normally and run the above script at build/setup/installation (this could also be automated by a post_change_branch_tip hook in a controlled environment). You'd put the original in a different directory so that there's less of a risk of it getting edited by accident.
We have a need to refactor a code base. The thing is that this will be done by one person and it would be desirable to avoid having the rest of the development team sitting idle while this job takes place.
We therefore tried the following scenario to see if it is possible to work in parallel.
Created file test.txt in directory first in developer A's workspace.
Promoted this file.
Updated developer B's workspace, thereby getting file test.txt
In A's workspace moved file test.txt to directory second.
Promoted this move.
In B's workspace edited file test.txt while it still resides in directory first (no update is made thereby emulating that work is done while refactoring is taking place).
Tried to promote and got a message saying that file test.txt had been modified (correct, file has been moved).
Tried to merge but got an error message saying that AccuRev can't merge since the file is missing in directory second (where it has been moved).
Tried to update B's workspace but that is not allowed since there is a modified file that needs to be merged first.
We are now stuck in a catch 22 situation.
We did try to place a fake file in directory second but that is not being recognized since this file does not belong to the workspace.
Has anyone out there tried something like this and gotten it to work?
It is of course possible to copy files but if there is a better way we would be grateful to hear about this. Or if this is a known bug or limitation in the tool.
We will contact also contact AccuRev support but I thought that I might be able to get some useful tips from the community.
Currently we are using AccuRev client 5.5.0.
Thanks for any suggestions on how to make the tool support this operation.
Referring to your steps 6 & 7: In AccuRev 5.5 after a file is edited and has a (modified) status you first have to keep before you can promote.
At step 8 you could try doing the merge from the Browse Versions view of the file. That way you can select any node to merge with, including the one that has been moved.
Step 9. An AccuRev update will not run successfully if one of the files to be updated is (modified). This is by design. You can keep the file so it has (kept)(member) status then run the update.
David Howland
After contact with AccuRev support the answer is that the only option available is to copy the file to some temp directory, revert the changes, update the workspace and copy the file into the new location in the workspace.
AccuRev will at least tell you which files you have to copy since they will be marked as modified.
I could experimentally verify David's remark to step 9 using AccuRev 5.5.
Let's assume that in the workspace of user A the file was moved and the move was promoted, while in the workspace of user B the file was modified and user B is about to promote his/her change.
Before the file is kept, it will not be possible for user B neither to merge nor to update. But after keeping the modified file the update is possible. The file is first marked as overlap, then the merge succeeds in the new location. Basically, this avoids creating a copy of the file, reverting it and restoring it in the new location after an update, which can be quite cumbersome, as AccuRev does not reveal easily where the move goes.
If user B promotes the modification before user A promotes the move, all goes smoothly, i.e. on update the moved file appears as overlap, but easily merges into the moved file in the new location.
Similar results are obtained when the two users have workspaces connected to different streams and the overlap occurs on a common parent stream. Only if the file is unkept, an error can occur (i.e. only if the move is promoted before the change). Then a simple keep allows to proceed as usual (update, merge, then promote).
I'm trying to do the following:
Read a file's attributes
If the attributes match a certain condition,
delete the file
Right now I'm using NSFileManager to perform a attributesOfItemAtPath:error: followed by removeItemAtPath:error:. I'm worried something will happen in between the two operations that invalidates the initial check.
What's the best way to make these two operations atomic?
Edit
The answers so far suggest file locking, which I have tried looking into. The closest thing I could find was setting the NSFileImmutable flag. But it seems like any other program could come along, unset it, and modify the file.. Is there a better way to lock a file?
Edit 2
Someone asked for a use case. Let's say I'm trying to keep two folders in sync. Any changes made to the files in one folder are mirrored in the other, and vice versa. If I delete file 1 from folder A, I will also delete file 1 from folder B. But if file 1 in folder B changes right before I delete it; then instead of deleting it, I want to sync it back to folder A
You can use mandatory (kernel enforced) file locking to lock the file in question to prevent changes being done to the file when you are operating on it. I know Linux and Solaris support mandatory file locking but I have no clue if OS X / HFS+ does and if so how to use it. Hope this helps.
So you have more than one attribute query then? If so, why not just lock the file before starting the queries? Once done, unlock. Then if delete, delete.
There's a way to lock a file with Cocoa; I googled and worked that problem a few days back, but I already forgot the specific message; sorry..
I suggest to use a message in order to accept or delete the file with this method:
fileManager:shouldRemoveItemAtPath:
The prototype of your development is to call method delete the file and in the method shouldRemoveItemAtPath: you accept (returns YES) or you reject (returns NO) as the file attributes values.
Hope this help
It seems to me that you should just go ahead and delete the files that matched. There's no point to locking unless you are worried some other app will change the file such that it can't be deleted. Think about it; you found a file that matches your delete criteria. You want to delete it. Does it really matter if it changes in the meantime?
I have a script file. Unfortunately I've overridden it with some other data. I need the old data. crtl+Z is not working.
How do I recover it?
unfortunately some editors are not supporting of crtl + Z so only not able to recover the data..
are you using file versioning? what OS, what version?
What is the File structure? NTFS?
if you overwrite a file in NTFS it tends to delete the first file and put in the second, not systematically destroy the file (so you can recover the file with an undelete utility.
first, rename the current file, then open an undelete utility (you don't want to download anything to this computer as you may overwrite the file.)
run it from a memory stick.
the safest thing to do if it's critical is to image the device off to a donor scratch media and work from there.
I am trying to watch files in a directory to determine when files are opened/accessed. I thought FileSystemWatcher would do the trick using the event Changed.
Problem is that some applications do not create a lock on the file they open/access or change either the date modified or date accessed (even after fsutil behavior set disablelastaccess 0). Notepad for example. Apparently is makes a copy of the file in memory and plays with it there until you save it. Nor does it update the Date Accessed.
How can I monitor a directory of files and be notified when a file is simply opened/accessed by any program (e.g. Notepad)? Files may be opened from another computer, not necessarily on the computer running the "watcher".
I found lots of similar questions but did not see one focusing on file "access".
This is quite normal. Updating an existing file is quite dangerous since it can cause irretrievable data loss. A disk error (like disk full) while writing is very bad news. The common algorithm used:
rename the original file
write a new file using the original name
no error: delete the renamed file
error: delete the new file, rename original file back
Clearly this doesn't cause a Changed event to be raised, no file was changed.
Sorry, I didn't read the question well enough. There is no notification whatsoever for an app just opening a file for reading. FSW can only detect changes to the file system. There is no ready alternative either, this requires a custom file system filter driver that snoops on driver requests. Like the kind that SysInternals' ProcMon utility uses. I'm not aware of such a driver ready for use in a C# program, you can't write them in C# either. This just isn't a common requirement.