Detect file in use by other process - objective-c

On windows and such I used to use a trick to find out of a file is currently in use (written specifically).
I use to open the file for writing and if it failed most likey another process is busy accessing it.
Sadly these trick (using C OPEN with exclusive lock for writing) doesn't work on my Mac. While my curl in a terminal is still writing my -fileBusy() check fails.
fcnt call on the fd with F_GETLK doesn't reveal any locking as well.
Is there any chance for me to detect if a file is in use by another process?
Ps> listening for fsevents can't be done because my app launches after the is created by the other app / process.

Apple confirmed via email that the solution described in the link below is a valid one and not considered a private API.
More information:
http://lists.apple.com/archives/cocoa-dev/2010/May/msg01455.html

You could try running the following shell command using NSTask:
lsof -Fc path/to/thefile
That will give you the process ID and name of any process(es) that have thefile open.

Related

Docker build fails always with error hcsshim::PrepareLayer - failed failed in Win32: Incorrect function. (0x1) Windows Containers

Steps to reproduce are very easy.
Create a Dockerfile.
My Dockerfile has many more lines, but I have trimmed them so we can focus in the source of the problem.
Said that, these two lines alone (without anything more) show the problem.
FROM microsoft/iis
SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue'; $VerbosePreference = 'Continue'; "]
Run docker build . and you get hcsshim::PrepareLayer - failed failed in Win32: FunciĆ³n incorrecta. (0x1).
Windows 10 Pro 1909 (but it happened too in 1903)
Docker version: 2.1.0.5
Engine: 19.03.5
Machine: 0.16.2
I have found the solution to the problem.
Reading all the https://github.com/docker/for-win/issues/3884 bug, some have found a simple solution: rename C:\windows\system32\driver\cbfsconnect2017.sys so it isn't loaded the next boot.
Disabling that driver enables me to do a docker build for the first time in windows containers in almost a year.
In my case Box Sync was the one using that driver.
EDIT: #GustavoTM have found that pCloud raises the same problem.
EDIT2: #VonC have noticed that some people in the issue in GitHub has solved it deleting this other file: C:\Windows\System32\drivers\cbfs6.sys. I haven't tried that, but i put it if it helps others.
The good thing is that I don't need to uninstall Box, but only rename that file.
This is still an issue (still open) with Win10.
Looks like uninstalling cloud storage providers with file system filters like Dropbox, Box, etc. as a workaround is an option for some users.
Deinstall cloud storage providers or virus scanners; if you identify which one is not working please share in https://github.com/docker/for-win/issues/3884
In my case was the problem similar but the file cbfs6.sys was placed somewhere in the rest of uninstalled application Jungle disk, somewhere in the folder c:\Program files\Jungle disk .... It's part of Callback File System signed by EldoS Corporation.
The folder could be rename only and not delete directly. So I could delete its immediately after the PC restart, before running the Docker. So it could be delete during the Docker service restart too.

How to run a script from startup on Raspbian 10 (buster)?

I have designed a GUI that I want to run as soon as I turn on my Raspberry Pi. It is currently set up to automatically log in as user on startup, but if that makes the process more difficult I can change that. My Raspi runs on Raspbian 10 (buster), which has made things difficult since I can only find tutorials for Raspbian 8 or so.
I have tried modifying autostart folder, but it is not in the same location as it was in previous Raspbian versions and doesn't seem to be working the way it used to. Tutorials have said to create a .desktop file in /home/pi/.config/autostart but I don't have a .config folder, or at least it's hidden. For me, autostart is in /etc/xdg/autostart and when I try to create a new file here using nano in the terminal, I get the message [Directory '/etc/xdg/autostart' is not writable] and it doesn't save my file.
I have also tried calling my script in /etc/rc.local but it did nothing. Some have said it doesn't work for GUIs.
Here's what I type into terminal:
$ nano /etc/xdg/autostart/gui.desktop
and a new file pops up, but at the bottom I get the warning [Directory '/etc/xdg/autostart' is not writable]
How can I get my GUI script to run on startup with Raspbian 10 (buster)?
There are a number of issues here, first when you are looking at tutorials recognize that Linux distros are built in layers, for simplicity let's say your "layer stack" looks like this: kernel, systemd, x11, xdg, lxde. The kernel boots, then starts systemd, which then starts x11 (and a lot of other stuff), x11 starts xdg (and some other stuff, I think), lxde is started by either x11 or xdg I'm not sure which.
You want to add something to this process, you can do it at the kernel level (bad idea), at they systemd level (probably not right unless its a daemon), at the x11 level (still probably bad as you still don't have a user session yet), or at the xdg or lxde level.
xdg is probably the right place as it has all you need ( a gui, a user session) while being common (xdg will still work if you switch window managers, probably)
With that out of the way, why isn't your solution of modifying xdg working? It's because '/etc/xdg/autostart' is a system configuration directory. Any changes made to it will apply to all users. You may want this, but the system is trying to protect other users on your system and only allows root to make changes to everyone. If you want to do that use "sudo" (documented elsewhere on stack exchange and the internet). If you want to do it just for you use ~/.config/autostart, (https://wiki.archlinux.org/index.php/XDG_Autostart) you might need to create that directory with "mkdir ~/.config/" and then "emacs ~/.config/autostart"
Would it be better to have the python program run in a terminal window from startup? That way you would see what it is doing in case of errors.
If so, perhaps check this out https://stackoverflow.com/a/61730679/7575617
By the way, in the file manager, hit CTRL+H to toggle viewing hidden files and folders.

How to get all the processes with a specified name in NSIS installer

I want to kill RunDll32 process which is started from my install directory.
So if I use
${nsProcess::KillProcess} "rundll32.exe" $R0
It kills all the rundll32 processes on the system which I don't want to happen.
IMO, I have two options to fix this,
1. Identify interested process from commandline parameters
2. Identify from process startup directory (current directory).
I see there are few plugins to find the process but what they do is they just return found or not found. Instead I want IDs of the processes or list of these processes and then I'll check each process for command line or startup directory information and will act on the the required process.
BTW, I checked following plugins
http://nsis.sourceforge.net/FindProcDLL_plug-in
http://nsis.sourceforge.net/Processes_plug-in
http://forums.winamp.com/showthread.php?t=230998
Thanks
I fixed by using wmic query as follows:
StrCpy $1 "wmic Path win32_process where $\"name like 'Rundll32.exe' and CommandLine like '%$0%'$\" Call Terminate"
nsExec::Exec $1
If you control the .dll then the best option is to provide some sort of way to shutdown the app in a clean way. Perhaps you could find a window based on its class name and send it a WM_CLOSE message.
If you just need to shutdown the application during upgrade/uninstall then the LockedList plug-in is much better than just killing processes...

Using WinSCP script for SFTP access from SSIS

I am new to WinSCP and am attempting to create a script file that will eventually be used with SSIS to download files from an SFTP site. A lot of the literature WinSCP includes explains the file downloading or uploading portions. For the time being, I just want to create a script to test the connection first and will build from there.
So far I saved the connection in WinSCP and have the following. The below code does not seem to function at all and I am not sure where else to go as I am still reading about the scripting for WinSCP. Is there a way or can someone point me in a direction to see if I am in fact connecting via through the script?
option batch on
option confirm off
open username#address
exit
Not sure what SSIS is (sorry) but I can tell you how I'd set it up from a windows batch file if that helps:
If you are open to using a different software, consider using cygwin. It mimics a linux shell so linux users on windows have a lot of linux utilities handy. That being said, there are some commands which can run on windows straight from command prompt (and thus batchable). What you'd need to do:
1) install cygwin
2) Create a "passwordless" login (using ssh-rsa authentication). To do this start your cygwin terminal and use the commands "ssh-keygen" and "ssh-copy-id" (more on that later)
3) Now you can run "sftp" from the DOS command prompt (does not require cygwin terminal) and sftp to your account. No password required because of step 2).
A few follow up info:
What can run from dos command prompt and what must be run from cygwin terminal?
If you go to the "bin" directory of cygwin (for me it's in c:\cygwin\bin) you can see all the cygwin utilities. Anything with "exe" extension can be run from dos command prompt. If no "exe" extension, must start cygwin terminal first
How to set up ssh-rsa authentication?
You can pretty much google "ssh login without password" and pull up a lot of results. This is common for setting up login from one linux system to another. You would be using the same steps using cygwin on windows. My instructions are here:
http://geekswing.com/geek/unix/how-to-ssh-login-without-a-password-using-ssh-keygen-quick-tutorial/
Storing session settings in WinSCP GUI and trying to access them from WinSCP script running in SSIS is generally a bad idea. I believe there's no example or guide on WinSCP site that would suggest doing that.
WinSCP stores its configuration in registry in HKEY_CURRENT_USER hive. The SSIS typically runs under a dedicated system account, that have its own HKEY_CURRENT_USER hive, and won't see the GUI configuration.
For details see WinSCP FAQ about your problem:
https://winscp.net/eng/docs/faq_scheduler
The best you can do is isolate your your script from configuration by using the session URL with the open command, instead of the stored site name.
See also https://winscp.net/eng/docs/scripting#configuration
Your actual problem can be completely different though. But that's hard to guess as you have not shared any details, such as error message, log file, etc.

Debugging Solaris OS crash

I have access to a remote Solaris terminal which crashes occasionally, and I have to ask someone with physical access to boot the machine up, which it does successfully. I would like to know which tools/files should I look at to find out the cause of the crash so that I can make the necessary configuration changes and avoid it in the future.
What tools you can use will depend on what version of solaris you have running and what the actual problem
is. The first thing to do is check the system console (which it sounds like you don't have access to) and the /var/adm/messages file. This file is updated with system messages and the newest will appear at the end.
Next, you can look for a system core file. If a core file is created, it would be in /var/crash/hostname where "hostname" is the name of the machine.
If you have an actual core file in the /var/crash/hostname directory, this set of commands will give you a good
string to search google with:
# cd /var/crash/hostname
Replace "hostname" with the hostname of your machine.
# mdb -k unix.0 vmcore.0
If you have multiple core files, select the most recent version.
> ::status
This should give you a panic message, cut and paste that into google and see what you can find.
For more core file analysis read this:
http://cuddletech.com/blog/pivot/entry.php?id=965