This may be a foolish question but I would appreciate any pointers: I'm generating year-long .Ics files that contain unique information people are actually purchasing - Moon phases, tides, etc.
The files work fine but I would like to try and 'lock' them so that the usual suspects cannot simply, download,rename and distribute the unique content to their advantage.
Does anyone know if anything like this exists? I've tried locking the file as text and but it doesn't stick once it's resaved as ics.
Related
The documents provided by APPLE did not make it clear to me. This may be my English level limit. I hope you can help me to get a better understanding of it.
I use the FileManager class to manage the files of icloud, including the methods of copyItem, moveItem, and removeItem. I directly deal with the files in the icloudDocument's address as an ordinary file. After matching with NSMetadataQuery, I compare the modification time and creation time of files, so I managed files, but I found it very bad, because I need to judge whether files need updating, uploading or deleting.
I later found that the FileManager class has Managing iCloud-Based Items, which includes the evictUbiquitousItem, startDownloadingUbiquitousItem, and other methods. It seems to be easy to manage, but it doesn't make me clear.
My problems are now:
which is the final file when the local file is not consistent with the icloud file? (there is no convenient method, automatic synchronization)
what should I do if the icloud does not exist, but when the local file exists? (delete it directly? Or is it necessary to judge?)
how do you know which files are downloaded to the local?
I think a student of mine renamed a PNG a Word document and intentionally submitted a corrupted file to buy more time (or something) on an assignment. The student denies everything and claims it was a computer malfunction. Before I submit an honor code violation I want to be sure that there's no explanation that does not involve cheating that I'm somehow overlooking.
Basically, I'm a TA and a student submitted a paper, let's say it was Smith.docx. When I was working on grading and went to open Smith.docx Word wouldn't open it and said that it was corrupted. I eventually had the idea of opening it in a text editor and there it was a massive jumbled file of all sorts of odd characters (total file size: 180kb for what was supposed to be a 5 page paper).
I noticed, though, that the first few characters of the file were:
‰PNG
I renamed the file Smith.png and it opened. Bizarrely, it was an image of the first page of a Word document. More specifically, it looks like a screenshot of a Word doc cropped so as to show just the page. What makes it seem like a screenshot is that the cursor thingy (the vertical bar marking where you're typing) shows up next to the title.
An additional interesting bit of data is that if I scroll further down in the file (opened in notepad) I come to this:
XML:com.adobe.xmp <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 5.4.0">
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<rdf:Description rdf:about=""
xmlns:exif="http://ns.adobe.com/exif/1.0/">
<exif:PixelXDimension>996</exif:PixelXDimension>
<exif:PixelYDimension>1286</exif:PixelYDimension>
</rdf:Description>
</rdf:RDF>
</x:xmpmeta>
I'm not sure what all that means but 1286x996 are the dimensions of the png image. The rest suggests to me that the file was created in some Adobe program but I'm not sure if that's right and how to figure out more about that.
So, my actual question: Is there any conceivable explanation of any kind for how I would come to have a file called Smith.docx that is a perfectly functioning png of what sure looks like a screenshot of the first page of a Word document other than that the student did it on purpose? The student claimed that their computer was "corrupting" files and that they had to take it into the Apple for service. I find this incredibly implausible (student has also not provided the receipt for this, which I requested).
Additionally, other than the case I laid out here, is there any positive evidence for my theory (that it was a straightforward case of cheating) that I can present to strengthen my case? eg, is the data from the file that I posted above a smoking gun that it was created in an Adobe program or is there any conceivable way that could come out of a Word document or other sort of corrupted file?
Also, is there anything else I can look for in the PNG file that would be a smoking gun?
Thanks in advance for any help you might be able to offer!
just rename the file with .png at the end instead of .docx and if it was a png then it should open just fine as a png
The key is that you see the cursor in the screenshot, there is no way Word would export (somehow) a docx file as a png AND draw the cursor for typing. Also, any tool that could do that would save the file as png not docx, only the user could deliberately change the file extension.
Also, does the screenshot show an empty document? or it looks like the final document your student delivered at the end?
Short answer:
The student is lying and is in fact a cheater (in my opinion).
Also, even if they were telling the truth, it is still their responsibility to have their work done, ready, and fully functional on time. Your computer is corrupting your files? Tough cookies. No one cares. You should have done your work on another computer. In the real world, excuses don't get you anywhere and they shouldn't get you anywhere in school either.
Lastly, it is very easy to re-name an extension of another file type and claim it's corrupt and very unlikely that a computer is just creating corrupted files. If their computer would otherwise create corrupted files, I would imagine it would be nearly impossible to get the computer to boot. In other words, they probably wouldn't have been able to turn on their "corrupted" computer to create "corrupted" files in the first place.
I find many similar question but i didn't get solution for this.
Is it possible to upload some file like image, document, zip file to upload on iCloud programmatically?
See table 4-1 in the documentation:
How do you manage the data? Manage files and directores using the
NSFileManager class. Open, close, read, and write files using standard
file system routines.
So if you can create a file, you can store it in iCloud. But remember there's a finite, relatively small amount of space available.
iCloud can handle all kinds of files. So if you want rot use an obscure file format or invent your own, go for it. It only can to be converted into a byte stream/NSData, but then again, what isn't?
Check this tutorial walkthrough app. It shows how to create, modify and delete files for iCloud.
http://github.com/lichtschlag/iCloudPlayground
Sweet..I bought myself a 1TB portable harddrives this week. Don't you just love how much data you could store on one of these disks? The fact that I could store my bluray rips on to my portable harddisk and that my lg lcd tv can do HD rips right from the drive - that's amazing practicality right there! However, life it seems, is never so simple. I have 100s of movies unorganized in one huge folder, which is exactly what I needed to annoy myself while browsing the same on my tv to play a single movie. That got me thinking...
What if I had an automated way to organize movies into folders such that my folder-browsing-on-a-lcd-tv-or-a-comp would make my life a little easy?
I started thinking about this... I browsed a little in this context and I realized that if only I could "tag my movies somehow and create folders on-the-fly based on tags using hardlinks", I would have addressed my problem. I googled a bit to find software that works in the above fashion, only to find none.
A few more days of serious thought (as you know by now.. I think a lot.. and I guess this question is starting to sound like a blog rant/post of sorts...), in the interest of humanity, I thought I should come up with a generic way to address this: What if someone wanted to organize photos... organize music.. organize software?!
Turned my grey cells off for a while and here is an approach I came up with to solving my what-if scenario.
Tag / Group tag individual files (rely on a slick GUI to do it fast and do it good) - Adobe Flex/Eclipse RCP to do this?
Create hardlinks to each of the tagged files.
The first point is self-explanatory. The second (coz I am talking windows here), refers to making use of mklink.exe.
Consider a scenario where I have 2 movie files: I have a movie file "Transformers.avi" tagged as "english, action, bluray, sci-fi, imdb-top-50, must-watch-with-kids" and another movie file "The Specialist.avi" tagged as "english, bluray, thriller, adult". Here are a few of the possible locations I want to see my Transformers to be found:
[root directory]->all-tags->english
[root directory]->all-tags->bluray
[root directory]->all-tags->english->all-tags->bluray
[root directory]->all-tags->bluray->all-tags->action
[root direcotry]->all-tags->english->all-tags->action->bluray->all-tags->imdb-top-50
Given that windows has a limit of 1024 hardlinks to a single file, I probably would be allowed 7 unique tags per file. Each sub-folder will have an "all-tags" folder. Having it named "all-tags" makes it more accessible when order by name.
I believe this approach when automated to let you configure tags you want and where the hardlinks are created for you, helps you organize stuff effectively.
I don't know if there are better things out there. I would like your inputs on this approach and other possible ideas. I would like to gather inputs here and release something to sourceforge for everyone to use in a couple of weeks. I am sure, I can count on your positive response as always.
I believe hardlinks are not a good approach. Reason? A standalone player won't play them, and I wouldn't like a program who's made for tagging to tell me to stop making so many tags because of a Windows limitation on hardlinks (remembering each tag will increment the number of links exponentially).
Plus, "help" is not a good tag.
And I've had an idea once that I'm still planning to make some day to sort my own files - put the files in a big storage each below a GUID foldername (filename untouched) and store metadata in a sqlite database to be used by a smart file browser.
I was considering doing something similar to this with music for detecting duplicate songs and auto-organize funcationality.
For your application, I wouldn't recommend using any shell programs through Java. Exception handling becomes difficult, and your application becomes bound by the shell interface and implementation (i.e. windows versions or installations affect your application behavior).
I would use a database with a few tables: Files, Tags, and an association table.
The Files table would list the physical location of each file, the filename, and a unique identifier. This way, you can maintain information about each file without having to modify it for every tag association.
The Tags table would list each tag, and any metadata you want to store for each tag.
A third table, maybe 'FileTags' would store the assocation between tags and files. When adding tags to the stack, you would add a statement to the WHERE clause, and the list of files with all of the tags would be returned. This structure would also allow open your codebase up to other designs, such as include/exclude (autocomplete with X buttons), or possibly search.
If implemented in Java, your app would be platform independent, and would allow a very large number of tags and files. You can then use the system default application for opening the media file, and the user can make the selection in their native OS.
Reiser4?
...
(I mean nevermind Hans, but the tech...)
[disclaimer: Not a hacker. I know nothing of programming/coding, never mind filesystems & databases. I can barely code decent HTML even, if at all. Hey y'all! :D]
[footnote: does plain HTML5 work here? Too lazy to close my tags hehe :p]
I would like to create my own data format for an iPhone app. The files should be similar structured as e.g. Apple's iWork files (.pages). That means, I have a folder with some files in it:
The file 'Juicy.fruit' contains:
Fruits
---> Apple.xml
---> Banana.xml
---> Pear.xml
---> PreviewPicture.png
This folder "Fruits" should be packed in a handy file 'Juicy.fruit'. Compression isn't necessary. How could I achieve this? I've discovered some open source ZIP-libraries. However, I would like to to build my own data format with the iPhones built-in libs (if possible).
Best regards,
Stefan
Okay, so there are three ways I am reading your question, here's my best guess on each one:
You want your .fruit files to be associated with your app via Safari/SMS/some network connection (aka when someone wants to download files made for your app or made by your app).
In this case, you can register a protocol for your app, as discussed here:
iPhone file extension app association
You want the iPhone to globally associate .fruit files with your app, in which case you want to look into Uniform Type Identifiers. Basically, you set up this association in your installer's info.plst file.
You want to know how you can go from having a folder with files in it to that folder being a single file (package) with your .fruit extension.
If that's the case, there are many options out there and I don't see a purpose in rolling your own. Both Microsoft and Adobe simply use a standard zip compression method and use their own extension (instead of .zip). If you drop any office 2007 document, such as docx or Adobe's experimental .pdfxml file into an archive utility (I like 7z, but any descent one will do), you will get a folder with several xml files, just like you're describing for your situation. (This is also how Java's jar file type works, fyi). So unless you have a great reason to avoid standard compression methods (I vote gzip), I would follow the industry lead on this one.
I can definitly appreciate the urge to go DIY at every level possible, but you're basically asking (if it's #3) how you can create your own packaging algorithm, and after reading how some of the most basic compression methods work, I would leave that one alone. Plus I really doubt that Apple has built in libraries for doing something that most people will just use standard methods for.
One last note:
If you are really gunning to do it from scratch (still suggest not), since your files are all XML, you could just create a new XML file that will act as a wrapper of sorts, and have each file go into that wrapper file. But this would be really redundant when it came time to unwrap, as it would have to load the whole file every time. But it would be something like:
Juicy.fruit --
<fruit-wrapper>
<fruit>
<apple>
... content from apple.xml
</apple>
</fruit>
<fruit>
<banana>
... content from banana.xml
</banana>
</fruit>
<fruit>
<pear>
... content from pear.xml
</pear>
</fruit>
<picture>
...URL-encoded binary of preview picture
</picture>
</fruit-wrapper>
But with this idea, you either have to choose to unpack it, and thus risk losing track of the files, overwriting some but not all, etc etc, or you always treat it like one big file, in which case, unlike with archives, you have to load all of the data each time to pull anything out, instead of just pulling the file you want from the archive.
But it could work, if you're determined.
Also, if you are interested, there is a transfer protocol intended specifically for XML over mobile called WBXML (Wap Binary XML). Not sure if it is still taken seriously, but if there is an iPhone library for it, you should research it.