Loading text files from any location in Objective C - objective-c

I haven't been able to make the application load a file except by putting a direct link to the file hard-coded into the application or putting the file into the same part of the file system as the program.
I am using the console interface for this application, and I just need it to ask the user what file to load, let them tell the program which file to use, then execute the rest of the code and return the results. Putting a direct link and putting the file in the same directory works, but this solution is useless because I need to be able to select various files from anywhere on the computer. Thanks for any advice.

Related

Is it possible to have .net console application that embed another executable file?

I have a single command line windows executable that has many options built into this exe file.
Eg:
(It can take screenshot)
ToolGo.exe printscreen c:\temp\filename.jpg yyyymmdd
(It can show up)
ToolGo.exe showIP machineA
I want to write another command line application, possibly in .net , where it can embed/build a wrapper around this ToolGo.exe file into my application without the user be able to use the ToolGo.exe, and also users can only access one function of this main exe file.
In the example I want this other tool to access only the print screen function in this new exe file.
The new application will have this:
Tool2go.exe printscreen c:\temp\filename.jpg yyyymmdd
But if someone types the following, it will not work:
Tool2go.exe showIP machineA
Or
ToolGo.exe showIP machineA
Any ideas how I can write this code to do this in a .net command line application?
This is a multi-part question, so I'll just give the main part of the issue as the answer with suggestions on handling the rest.
You can embed a .exe into your program by clicking on Properties and navigating the the Resources section, and adding that .exe to it.
After that, it's just a matter of extracting it locally so you can pass your commands to it, and handle it's responses. (I'm not really aware of any way to do so w/out first extracting the. exe; the .exe itself needs to run somehow after all).
To extract the embedded .exe, you do this:
' Extract the MyProgram resource (i.e. your .exe)
Dim b() As Byte = My.Resources.MyProgram
' Write it to the user's Temp folder
File.WriteAllBytes(Environment.ExpandEnvironmentVariables("%TEMP%\MyProgram.exe"), b)
By extracting it to the user's Temp folder, you can pass it your commands, and since it's 'out of sight' the user probably won't even know it's there to directly use it themselves, unless they're a bit more advanced and visit their Temp folder often. You can slightly help to avoid this, but extracting the .exe when your program starts, and then deleting it when it exits, so it only exists on the user's system while your program is running.
As far as what the user can and cannot type in order to pass to the program, you can simply handle the filtering with your program; since your program is the one passing the commands to the .exe, just don't pass any commands that you don't allowed, and pass the ones you do want allowed.

custom file open with custom application only

I am working on vb.net application where I wanted to create and read a file. File will have specific extension for ex. .abcb the way I want my application to work is:
can create a file with .abcd extension
should read .abcd files only(and also application created files only so altered extension shouldn't be working)
.abcd files should show some garbage data when open in any other application(ex. word, notepad any image viewer etc.)
Now my application does 1,2(partly) step, i.e. it creates a file and load data also, it reads .abcd files only(not the altered files)
but created file can be read by other software's also.I tried searching a lot but have not found anything and don't know where to start.
Any help is appreciated!
if you don't want other programs to be able to read the content of your file then your going to have to mask it in some way, which is usually done with encryption.
assuming your not too worried about the key being compromised, the easiest way to accomplish this would be to generate a key with something like System.Security.Cryptography and use that key to encyrpt everything you send to the file and everything you read from it.
as for making your own file extension, you can make the extension of a file whatever you want when you make it:
Dim fs As FileStream = File.Create("/path/to/file/filename" & ".abcd")
the only thing that the extension does is tell the OS what progam to use when opening a file by default, which will probably be notepad since your making your own extension

Preventing other application from opening custom file vb.net

I have a text file. Now I have changed its file type from .txt to .abc. My VB.NET program loads the text into textboxes from that file. After changing the file type, however, other apps like NotePad and Word are able to open and read my .abc file.
Is there any way that only my application will be able to open/read from the file and no other app would be able to do so? What I mean is, suppose I have a PhotoShop document .psd file, no other app, rather that photoshop itself, can open it. How do I make my file unreadable by other apps?
There is no way to prevent an app that you don't develop from opening any file. The extensions are just there for helping us humans, and maybe a bit for the computer to know the default app you select for an extension.
Like you said, a .txt file can be opened by many many apps. You can open a .txt file with Notepad, Firefox, VSCode, and many others.
Same way, a .psd file can be opened by many many apps. You can open that .psd file with Photoshop, but also Notepad, Firefox, and VSCode, and probably the same apps as above.
The difference is which apps can read and understand the file.
In order to make a file not understandable by other apps, you need to make it into a format that cannot recognize, because you planned it "in secret".
Like Visual Vincent said above, you could encrypt the file in a way, or you can have a binary file, that basically only your app knows know to understand.
Since you dont own the app you want the file to be understood by, then you either have to accept that it can be opened by any app that can open files, or you can try to encrypt the file outside the app, or like zipping it with a password, and then decrypting or unzipping when you want to use it.
Firstly, any file can be read unless it is still open by a particular process or service. Even PhotoShop files can be 'read' by NotePad - try it!
So, an attempt at my first answer...
You can try a couple of methods to prevent opening the file, for instance, applying a file lock. As an example, SQL Server .mdf files are locked by the SQL Server service. This happens because the files are maintained in an open state, however; your application would have to remain running to keep these files open. Technically, though, the files can still be copied.
Another way is to set the hidden attribute for the file. This hides the file from the less savvy users, but it will be displayed if the user show's hidden files.
And my second answer: You refer to the format of files by saying only PhotoShop can read or write its own files (not true, but I know what you're saying).
The format of the file must be decided by yourself. You must determine how you are going to store the data that you output from your application. It looks like you have been attempting to write your application data into a text file. Perhaps you should try writing to binary files instead. Binary files, while not encrypted, as suggested by Visual Vincent in the comments to your question, still provide a more tailored approach to storing your data.
Binary files write raw binary data instead of humanised text. For instance, if you write an integer to the file it will appear as a string of four bytes, not your usual 123456789 textual format.
So, you really need to clarify what data you want to write to the file, decide on a set structure to your file (as you also have to be able to read it back in to your application) and then be able to write the information.

adobe acrobat actions or batch processing - js get paths of all files in a folder

So I would like to create an action that will take a folder, and display/store its contents filenames (as I would later want to manipulate the files on this folder via their filenames). I believe this is achieved via javascript.
I did the ff:
create new action
-> starts with -> A Folder on my Computer
I have no idea what to do next.
Any help would be awesome.
Thanks
A document's path can be accessed via this.path, the file name can be accessed via this.documentFileName. If all you want is a list of paths, you could print them to the console via console.println(this.path);.
There are likely better methods to achieve your objective than via Acrobat's batch processes, but without more detail, it's hard to point you in a direction.

Recommended document structure. File Wrappers? Roll my own?

I'm currently working out the best structure for a document I'm trying to create. The document is basically a core data document that uses sqlite as its store, but uses the Apple provided NSPersistentDocument+FileWrapperSupport to enable file wrapper support.
The document makes heavy use of media, such as images, videos, audio files, etc. with potentially 1000s of files. So what I'm trying to do is create a structure similar to the following:
/myfile.ext/
/myfile.ext/store.sqlite
/myfile.ext/content/
/myfile.ext/content/images/*
/myfile.ext/content/videos/*
/myfile.ext/content/audio/*
Now, first of all I went down the route of creating a temporary directory and placing all of my media in there. Basically creating the paths and file names '/content/images/image1.jpg' as I wanted them to appear in the saved file wrapper, and then upon save I attempted to copy these all into the filewrapper...
What I found was that the files were indeed copied into the wrapper with the file structure I wanted, but when the actual wrapper was saved, these files all magically disappeared.
Great.
So, I trashed my existing solution and tried to use file wrappers instead. This solution involved creating a content wrapper file directory when a new document was created, or loading in a content directory file wrapper upon opening a document.
When an image was added/modified, I created the necessary directory wrappers inside this root content wrapper (i.e. an images directory wrapper if it didn't already exist, or any other intermediary directory wrappers that needed to be created) and then created a regular file wrapper for the media, removing any existing wrapper for that file name if one was there.
Saving the document was just a case of making sure the content file wrapper was added to the document file wrapper, and the document would save.
Well... it did. The first time. However, any attempts to make any subsequent changes i.e add an image, save. Then replace image, save. Did not behave as expected, only showing the image from the first save.
So, my question is... first of all, which of the above approaches is the correct one, if at all, and what am I doing that wrong for them to fail.
And secondly, as I expect to be managing 1000s of images, is using file wrappers the correct way to go about things at all.
With that much media in play, you should likely give your users control over whether the media resides in the document or only a reference to the media is included in the document, and the media resides elsewhere, such as in a library/repository managed by your application. Then they could save out a (potentially many times larger) copy with all references resolved.
You might want to zip/unzip any directory so that users don't get confused trying to attach the document to an email. I believe iWork has been doing this with its document bundles for a while now.
As far as what you are doing wrong, no-one can say, as you haven't provided any code demonstrating what you are doing.
Why don't you create a one-off application that lets you select files on disk and saves those files in a document using a file wrapper? This would let you tackle this functionality without any interference from other issues in your application. Once you understand how to use file wrappers, you can port the code back or just write new code that works.