If a user opens a file in a program (for example using GetOpenFileNameW, DragQueryFileW, command line argument, or whatever else to get the path, and a subsequent CreateFileW call), is there a way to find the next file in the parent directory of the opened file?
The obvious solution is to cycle through the results from FindNextFileW or NtQueryDirectoryFileEx until the opened file is encountered, and just open the next file.
However, this seems undesireable.
First, because these functions use paths (instead of for example a handle), the original file is decoupled from the search algorithm, so the original file might not even get encountered in that search. This is not much of an issue (as failing in this case is the expected outcome), and it probably could be resolved with (temporarly) changing the sharing mode, using LockFile or similar (though I would like to avoid that).
Second, this cycling search would have to be done every time, because the contents of the directory might have changed (retaining hFindFile does not work, because only FindFirstFileW calls NtQueryDirectoryFileEx and enumerates the contents of the directory). Which seems like unnecessary work and might even affect performance (for example if the directory contains a lot of files).
In theory any file system has some way of enumerating the files in a directory. Meaning there is some ordered data structure of the files' metadata. And getting the next file should only involve going back from the existing file handle to that file's entry, and then getting the next entry from that data structure. So there does not seem to be a fundamental reason why this cannot be done more sanely.
I thought maybe there exist a better way to do this somewhere in WinAPI...
Same question for finding the previous file.
I'm having trouble monitoring a file for changes. I need to be able to know when a file changes, and when it does, I need the new line that was added. I intend to parse each line and find ones that match certain criteria, and act on information in those lines. I know the expected number of matching lines ahead of time, but I do not know how many lines in total will be added to the file, or where the matching lines will be.
I've tried 2 packages so far, with no avail.
fsnotify/fsnotify
As fas as I can tell, fsnotify can only tell me when a file is modified, not what the details of the modification was. Since I need to know what exactly was added to the file, this is no good for me.
(As a side-question, can this be run in a loop? The example that I tried exited after just one modification. I need to monitor for multiple modifications.)
hpcloud/tail
This package tries to mimic the Unix tail command, but it seems to have its own issues. The output that I get includes timestamps and other data - I just want the added line, nothing else. Also, it seems to think a file has been modified multiple times, even when it's just one edit. Further, the deal breaker here is that it does not output the last line if the line was not followed by a newline character.
Delegating to tail
I came across this answer, which suggests to delegate this work to the tail command itself, but I need this to work cross-platform (specifically, macOS, Linux and Windows). I don't believe that an equivalent command exists on Windows.
How do I go about tackling this?
#user2515526,
Usually changed diff is out of scope of file watchers' functionality, because, you know, you could change an image, and a watcher would need to keep a track several Mb of a diff in memory, and what if we have thousands of files?
However, as bad as it sounds, this may be exactly the way you want to implement this (sure, depends on your app, etc. - could be fine for text files), i.e. - keeping a map of diffs (1 diff per file) since last modification. Cannot say I like it, but sounds like fsnotify has no support for changes/diffs that you need.
Also, regarding your question about running in a loop, maybe you can get some hints here: https://github.com/kataras/iris/blob/8370d76910cdd8de043753ed81ae080eae8dc798/utils/file.go
Its a framework that allows to build a server that watches for TypeScript file changes. So sounds similar to your case/question.
Cheers,
-D
I do some Word automation filling in the blanks in some Word documents which are used as templates.
One template is used more often than the others, and this causes the error, as it locks out and Word is unable to open it, though I wish to open it in read only.
Opening the document
do until lole_word.Documents.Count = 0
lole_word.Documents[1].Close(lole_word.SaveOptions.wdDoNotSaveChanges)
loop
boolean lb_readOnly
lb_readonly = true
lole_word.Documents.Open(as_fileIn, lb_readOnly)
The problem is that the template document is opened once, with no flaws of any kind. But when the same template has to be reused, although the lole_word.Documents.Count always returns 0, when Word opens the previously used template, it is locked out, and Word finally shows up asking me whether I want to open it in read only mode.
I wish to avoid this annoyance and simply open the file in read only mode, as it shall be saved elsewhere once it is filled in.
My problem is that even though I specify open in read only mode by setting the second parameter to true, Word doesn't seem to see it this way and still pops up his File Already in Use by Another User dialog, and then my application loses control over Word and it crashes.
We had a similar problem and I wish that I could remember how we solved it. We may have used the Quit command. I know that we also did an attempted FileOpen in exclusive mode (with no intention of using the file) and immediately closing it. If we got a file locked return code we prompted the user to close out of excel first because there were times they would have the program open outside of OLE. I know this isn't exactly what you were looking for but hope it leads you somewhere. I recall this being an intermittent problem and there were some cases users had to open task manager and kill the extraneous excel process.
I vaguely remember the locking being caused by the file system and not Word, as we were opening in read only as well.
I have been facing this problem for sometimes now, a laziness caused in part by the fact that Microsoft Office automatically save files you are working on with versions and automatic recovery.
Many times when I am starting a new notebook in mathematica to do some tests or whatever, I often forget to save what I am doing.
Every now and then, depending on the computer I am using, the computer crashes and all the beautiful work I was doing is lost forever...
Is there a way to get around this other that manically saving my files every five minutes? How about file versioning?
BTW: Using MMA V8
Regarding autosaving, you may want to check out the NotebookAutoSave option, which can be set to True through Fromat->Option Inspector. You have to choose "Selected notebook", then go to Notebook Options -> File Options, and set NotebookAutoSave to True. Then, your notebook will be saved after every evaluation. Whether or not this is a satisfactory solution, of course depends on the situation.
But my experience is that the most reliable way is to develop a CTRL+S reflex - this one never lets me down and is working quite well.
As for the versioning, it is much easier with packages, for which you can use WorkBench which has integrated support for CVS and support for SVN via Eclipse plugin. For notebooks, I refer you to this SO thread. You may also find this Mathgroup discussion of some interest.
EDIT
For M8, for auto-saving purposes you can probably also run
RunScheduledTask[NotebookSave[EvaluationNotebook[]],{300}]
But I can not test this code at the moment
EDIT2
I just came across this post in the Toolbag repository - which may also be an alternative for the autosave part of the question (but please see also the discussion in comments on the relative advantages of scheduled tasks vs. Dynamic)
Since you have MMA version 8 you could use:
saveTask = CreateScheduledTask[FrontEndExecute[FrontEndToken["Save"]], 5*60];
StartScheduledTask[saveTask];
to save every 5 minutes (change the term 5*60 for other timings).
To remove the auto-save task use:
RemoveScheduledTask[saveTask];
To save only a fixed, specific notebook, store its handle in nb (finding it using Notebooks, SelectedNotebook, InputNotebook or EvaluationNotebook) and use FrontEndToken[nb,"Save"] instead of just FrontEndToken["Save"]
I have a Mathematica package that provides auto-backup functionality. When enabled, the current notebook--call it "blah.nb"--will be backed up to "blah.nb~" after a configurable amount of time has elapsed. I use it constantly and it has saved me from losing work many, many times. It's better than autosaving since it doesn't touch the actual notebook file: if you screw something up or something gets corrupted you don't want to overwrite your main file. :)
It's on GitHub here.
I've got an autosave routine that saves a copy of every open, modified notebook every 5 minutes (or whatever interval you prefer. It leaves your manually-saved copy alone, and saves a "swap file" in a separate directory that can be easily recovered if need be. The code (to be copied to init.m) is given in this answer: https://mathematica.stackexchange.com/questions/18380/automatic-recovery-after-crash/65852#65852, and copied below:
Motivated by the same concerns, I wrote the following code and added it to my init.m file. There are two main entries you'll want to change to use this. The global variable $SwapDirectory is where the swap files are saved (by swap file, I mean it in the VIm sense; an "extra" copy of your notebook, separate from your manually saved copy that periodically saves any new work). The swap files are organized within the swap directory in a directory structure which "mirrors" their original file locations, and have ".swp" appended to their file names. The other variable you might want to change is the number of seconds between autosaves, indicated by the "300" (corresponding to 5 minutes) near the bottom of the code below. At the appropriate times, this code will (automatically in the background) save swap files for ALL open notebooks, unless they are unmodified from their manually-saved versions (this exception makes the code more efficient, and more importantly, prevents the storage of swap files for documentation notebooks, for example).
In its current form, the code does not filter for only the input cells, but hopefully you can use the other answers to make that modification yourself.
Some things to note:
1) the Mathematica Put command seems to have trouble writing to network drives, even when offline access is enabled. Therefore, it is probably best to choose a SwapDirectory that is on your local machine.
2) Within SwapDirectory, you should create a sub-directory called "Recovery". This is where the AutoSaveSwap routine will make an initial save of any notebooks for which there is NO existing manual save location.
3) Simply evaluate
RecoverSwap["filePath"]
where "filePath" is a string representing the filePath of the MANUALLY-SAVED copy of the file (i.e., not the file that was created by AutoSave). This will then pop up a window containing the most recent auto-saved version of the file. The manually saved version is NEVER overwritten, unless you explicitly choose to do so. Once the recovered version pops up, you can save it whereever you like, or discard it at your discretion.
4) You should probably add this code to the KERNEL version of init.m ($UserBaseDirectory/Kernel/init.m) rather than the frontend version... this way, if you quit and restart the kernel, the autosave feature will also restart. On the other hand, this means that you must evaluate at least one expression after each start or restart to begin auto-saving. Once this initial evaluation is done, you do NOT need to have evaluated a cell for it to be backed up (unlike the built-in autosave utility).
Hope this helps someone! Feel free to respond with any questions, suggestions, or requests for improvement you may have. And, if you find this post useful, upvotes would be most appeciated! Take care.
$SwapDirectory= "C:\\Users\\pacoj\\Swap Files\\";
SaveSwap[nb_NotebookObject]:=Module[
{fileName, swapFileName, nbout, nbdir, nbdirout, recoveryDir},
If[ ! SameQ[Quiet[NotebookFileName[nb]], $Failed],
(* if the notebook is already saved to the file system *)
fileName = Last[ FileNameSplit[ NotebookFileName[nb]] ];
swapFileName = fileName <> ".swp";
nbdir = Rest[FileNameSplit # NotebookDirectory[nb]];
nbdirout= FileNameJoin[ FileNameSplit[$SwapDirectory]~Join~nbdir]<>"\\";
If[!DirectoryQ[nbdirout], CreateDirectory[nbdirout]];
nbout = NotebookGet[nb];
Put[nbout, nbdirout <> swapFileName],
(* else, if the file has never been saved, save as untitled *)
recoveryDir= $SwapDirectory <> "Recovery\\\";
fileName= ("WindowTitle" /. NotebookInformation[nb])<>".nb";
NotebookSave[nb, recoveryDir <> fileName]
]
];
RecoverSwap::noswp= "swap file `1` not found in expected location";
RecoverSwap[nbfilename_String]:=Module[
{fileName, swapFileName, nbin, nbdir, nbdirout},
fileName= Last[ FileNameSplit[ nbfilename] ];
swapFileName= fileName <> ".swp";
nbdir= Most[ Rest[FileNameSplit # nbfilename] ];
nbdirout= FileNameJoin[ FileNameSplit[$SwapDirectory]~Join~nbdir]<>"\\\";
If[ FileNames[swapFileName, {nbdirout}] == {},
Message[RecoverSwap::noswp,nbdirout <> swapFileName]; Return[],
nbin= Get[nbdirout <> swapFileName]; NotebookPut[nbin]
]
];
AutoSaveSwaps= CreateScheduledTask[
SaveSwap /# Select[Notebooks[], "ModifiedInMemory" /. NotebookInformation[#]&],
300
]
StartScheduledTask[AutoSaveSwaps]
I am trying to understand the code in this page: https://github.com/corroded/git-achievements/blob/gh-pages/git-achievements
and I'm kinda at a loss on how it actually works. I do know some bash and shell scripting, but how does this script actually "store" how many times you've used a command(im guessing saving into a text file?) and how does it "sense" that you actually typed in a git command? I have a feeling it's line 464 onwards that does it but I don't seem to quite follow the logic.
Can anyone explain this in a bit more understandable context?
I plan to do some achievements for other commands and I hope to have an idea on HOW to go about it without randomly copying and pasting stuff and voodoo.
Yes on 464 start the script, everything before are helping functions. I dont know how it gets installed, but I would assume you have to call this script instead of the normal git-command. It just checks if the first parameter is achievement, and if not then just (regular) git with the rest parameters is executed. Afterwards he checks if an error happend (if he exits). And then he just makes log_action and check_for_achievments. log_action just writes the issued command with a date into a text file, while achievments scans for that log file for certains events. If you want to add another achievment you have to do it in this check_for_achievments.
Just look how the big case handles it (most of the achievments call the count_function which counts the # usages of the function and matches when a power of 2 is reached).