I can't figure out why my calls to NSFileWrapper's addRegularFileWithContents:preferredFileName: is setting the files quarantine bit (as seen when using xattr -l on the file) when in the sandbox only. My app saves files in the document bundle so this I think is the method I need to use but the quarantine bit is driving me crazy.
Maybe this is a feature of some sort but my app also chmod's these files as executable and runs them as shell scripts using NSTask. However with the quarantine bit on I get errors from the bash shell (this has been well documented on stack overflow).
Has anyone else experienced this and do you know if these are bugs or features? The only way to work around it for now is to know the shell of the file in advance and not rely on the interpreter at the top of the file (i.e. #!/usr/bin/php) but this an annoying hack to work around a problem that shouldn't be.
Related
stripis a unix command to remove all the debug information from an executable, or other information that is not needed for execution. Is there a way to "strip" a macos app to make it smaller and make reverse engineering more difficult? I tried viewing package contents, and striping /macOS/MyGame executable, but then it claimed that it messed it up, and then refused to launch. How do I strip it without "invalidating the code signature" I already asked and I need help.
What is your purpose?
If you plan to distribute the app then using XCode's archiving options is the way to go.
strip command works in MACOS.
Here is a useful script:
https://gist.github.com/neonichu/1662881
I've implemented an OSXFUSE-based file system. It works fine on 10.8, but on Mavericks MS Word opens existing documents as blank (although I am, apparently, returning the correct data - I see the contents in the preview icon. Also, if I copy a file to a real hard drive and open it, it opens fine).
This issue is fixed on Mavericks if I mount my filesystem with the "local" flag. However, using this flag introduces other problems - e.g., it looks like it causes Finder to do some more aggressive caching, hence some file are not visible in Finder (although I can ls them in terminal).
Ideally I want to be able to mount the filesystem without this local flag (my implementation stores file on the network, so passing this flag looks wrong), but the problem with blank Word documents really puzzles me.
We have been able to track down the problem to - wait for it - Google Chrome. When Google Chrome is running while the volume is mounted, the problem appears. If Google Chrome is not running, Word/Excel/etc. files open just fine.
We've been in contact with Benjamin (OSXFUSE developer). Please also see his answer regarding this issue on the OSXFUSE mailing list:
https://groups.google.com/d/msg/osxfuse-group/URlw-n-Qakg/bLw2fHHDe7sJ
So far I have not found any bugs in osxfuse that might explain this behavior. The odd thing is that the files are not corrupted or empty. After copying the files to another volume they open just fine. Using LibreOffice to open the file on the FUSE volume works, too.
Chrome and Office seem to be based on the Carbon framework (which is deprecated since Mountain Lion). I believe the issue is somehow related to Carbon since non-Carbon apps do not seem to be affected. Every time a volume is mounted Chrome queries the volume’s capabilities and attributes (and maybe more). As far as I can tell all these file system operations return successful without any errors. But from this point on Office will fail to open documents.
In my opinion the two most likely reasons for this are:
osxfuse might break the VFS file system contract on Mavericks. I’ve been looking into this for some time now but I have not found any clues supporting this.
There might be a bug in the Carbon/CarbonCore framework. The odd thing is that there are no issues when using the stock network file systems afp or smb.
The two possible "fixes" (or rather "workarounds") for this issue seem to be (for now):
Use the "local" mount option (which might introduce other problems and is generally not recommend to use)
Do not use the "volname" mount option. The problem seems only to occur when the "volname" mount option is used. If no custom volume name is set, the problem seems not to occur and Excel/Word/etc. files open just fine - regardless whether Google Chrome was running at mount time.
I've seen the same and likewise local is not an option. Similar problems with Photoshop.
Some findings from my implementation
The problem doesn't occur on first run after reboots.
The problem begins occurring after program exit.
I solved this problem by manually dismounting (and waiting a few seconds) before exiting my program. If unmount is successful, on next run the mount again performs fine.
If the program ever terminates or dismounting fails (file in use, etc) then the volume's read-access is borked in Word/Photoshop on next mount.
Rebooting resolves issue.
Does this match what you're seeing?
We've got a fairly mature cross-platform game engine which we've had running on OSX for several years now without a hitch; we recently upgraded the game from SDL 1.2.15 to 2.0, and at some point in the conversion, I goofed something up and now we have a bizarre problem where the app launches just fine from the terminal, but when you launch the app from a double-click in the Finder, it just bounces once in the dock and just goes away.
We're baffled because insofar as I can tell, there's only a one-liner being printed in Console.app: Exited with code: 255 (naturally running from the terminal doesn't help here because we can't reproduce the problem there; the app runs fine when launched in a terminal).
So the only thing we can figure is it's either something we're goofing up in our main.cpp, or something we've hosed in how I set up the dylibs/frameworks. It's also possible that it's something to do with the working directory not being set right, but to the best of my abilities, I believe we're doing it right (regardless of your current working directory; the app attempts to forcibly set said directory to be in the Resources folder - this was necessary to get the game to launch, but I don't know if we're doing it wrong). This feels like a somewhat awkward fit for stackoverflow, for which I apologize, since it's not a simple "paste this code and ask what's wrong" job. I have two ways for you to reproduce it; firstly we are an open-source project, and you can get our source code (complete with a mac project file and all dependencies included in the repo, set up and ready-to-go exactly as I've perhaps erroneously created them), at our github page. The one change you'll need to do is open a file at the root level, named master-config.cfg, and remove the // comments from it (so the engine knows you want to launch a simple demo game shipped with the engine).
Alternately, I have a stripped down (~15mb zipped) binary you can directly download and try to run, if that's sufficient to diagnose the problem.
As said before, we're open-source, so we welcome any pull-requests for fixes!
You need to write a minimal Cocoa wrapper so that OS X will not SIGKILL you for not launching properly. I will give you a pull request with that wrapper.
If while an application is running one of the shared libraries it uses is written to or truncated, then the application will crash. Moving the file or removing it wholesale with 'rm' will not cause a crash, because the OS (Solaris in this case but I assume this is true on Linux and other *nix as well) is smart enough to not delete the inode associated with the file while any process has it open.
I have a shell script that performs installation of shared libraries. Sometimes, it may be used to reinstall versions of shared libraries that were already installed, without an uninstall first. Because applications may be using the already installed shared libraries, it's important the the script is smart enough to rm the files or move them out of the way (e.g. to a 'deleted' folder that cron could empty at a time when we know no applications will be running) before installing the new ones so that they're not overwritten or truncated.
Unfortunately, recently an application crashed just after an install. Coincidence? It's difficult to tell. The real solution here is to switch over to a more robust installation method than an old gigantic shell script, but it'd be nice to have some extra protection until the switch is made. Is there any way to wrap a shell script to protect it from overwriting or truncating files (and ideally failing loudly), but still allowing them to be moved or rm'd?
Standard UNIX file permissions won't do the trick because you can't distinguish moving/removing from overwriting/truncating. Aliases could work but I'm not sure what entirety of commands need to be aliased. I imagine something like truss/strace except before each action it checks against a filter whether to actually do it. I don't need a perfect solution that would work even against an intentionally malicious script.
You can prevent a script from overwriting through I/O redirection by
set noclobber
Preventing overwriting by cp and the like is harder. My inclination would be to reset the PATH for the script to run with PATH containing just a single entry, a "blessed" directory where you place commands that you know are safe. This might mean, for example, that your version of cp is arranged always to use the --remove-destination option (probably a GNU-ism). In any case, you arrange for the script to execute only commands from the blessed directory. You can then vet each such command individually.
It would be good if you could prevent a script from executing a command by absolute pathname, but I don't know how to do that. If you are doing installations in your regular directories, a chroot jail probably does not help unless you do a lot of loopback mounting to make those directories visible. And if the directories into which you're installing contain dangerous commands, I don't see how you can protect yourself against them completely.
Incidentally, I tried and failed to learn if install(1) removes the desitination before installing. It would be interseting to learn.
Bash script I presume? Is the script very long? If not, you can do this manually:
if [ ! -f /tmp/foo.txt ] #If file does not exist
then
...code
fi
But I think you're asking for a way to wrap this around the script. You can certainly monitor the file writes with strace but AFAIK it doesn't have the functionality to interrupt them, unless you set up some sort of Intrusion Detection System with rules etc.
But to be honest, unless it's a huge script, that's probably more trouble than it's worth
Write your own safe_install() functions and make sure they're the only methods used. If you really need to be sure, run two processes. One would have permissions to make changes and the other would drop all privileges early and tell the other script to do the actual disk work.
I'm working on a GUI for Windows XP. Everything works great, except when I run an external command through backticks, %x(), IO.popen, etc, I get a DOS window that pops up for a split second. I know this doesn't happen when I've developed on OS X and Linux. Any ideas on how to get rid of it? (Or at least hide it?)
I'm using rubyw 1.8.6 (the "GUI version" of Ruby for Windows) and GTK2 for the interface.
You can use the Win32API module, and call the windows api CreateProcess Function. It ain't pretty.
As mentioned in a comment, I never found a solution to this. In this particular circumstance, the information I needed was actually already stored on the filesystem (so I just read it in as a file). This wasn't immediately obvious before, and isn't likely to come up in all circumstances.
If anyone finds a "true" solution, I would be interested in hearing about it.