Meaning of the character '@' in output running 'ls -l'

folkertmeeuw wrote:

I'm preparing for LPIC exams. In Numbers I do a compare sheet between OS (Debian, Ubuntu, Fedora, MacOS, Solaris) and the commands. Sheet has now 355 lines and I'm not finished yet.

For those platforms that meet The Open Group UNIX specs, you will have a subset of similarity.

Outside of that, they’ll often differ.

Having created a whole lot of platform comparison spreadsheets over the aeons, those spreadsheets are less than useful.

Outside of homework, that is.

For portable apps or when porting OSs I’ll usually go with a consistent subset of features from platform hardware and OS software, and from compilers, and a shim for the platform differences. Which unfortunately starts looking like any other platform portability layer; what amounts to a hardware abstraction layer or HAL.

355 is not even a fraction of the scale and scope.

Did you look at the man page for ls? It explains all of that.

See the explanation of the "Long Format."

Perhaps you have the Problem Problem?

You have a problem you don't know how to fix, but you think it is related to something else that you try and you have a problem with that. You then post here asking about the second problem instead of just asking about the actual problem. It seems that problem might be differences between Linux and Unix--there are many, most subtle. I don't know much at all about Linux, but I do know you can't take a Linux example and expect it to work on Unix.

folkertmeeuw wrote:

I've been working with cron and crontab on MacO's Sonomia and the shell expansion for the standard data or DATE command today. Lost time in the end, because the last post in the thread https://serverfault.com/questions/45066/os-x-cron-and-environment-variables made me realize once again, MacOS is different and I can't compare it with Linux, the differences and peculiarities are serious. Well, I'll just write .plist files to do my tasks, if that's the way it should be.

It isn't. Don't believe what you read on the internet. Especially things written 15 years ago about an OS that now gets updated yearly.

And what does that tell me?

Those are just extended attributes. Regardless of whether you want to use cron or launchd directly, extended attributes don't matter.

folkertmeeuw wrote:

Yes I did! But wasn't helpful. Could it be that the '@' can be observed, when launchctl load, enable or start is called?

You didn’t read the part where the @ means there are extended attributes which is what you asked about. If your question was about extended attributes, probably look for a book about the Mac OS Extended or Apple File Systems.

folkertmeeuw wrote:

Not quite a problematic problem. It is partial knowledge for the LPIC-1 certification.

LPIC?

Again, though Linux was very much inspired by and shares with various similarities to UNIX, Linux is in its own and very separate part of the operating family system tree.

If you want to learn macOS or another BSD-descended UNIX, or Open Group UNIX, a Linux material is far from the best path. It’ll be inapplicable to many details, at best. Apple has certification material that will be much closer to macOS reality, as will Open Group UNIX certification materials. This if you want to follow the certification path.

folkertmeeuw wrote:

Thx for answering. Spreadsheets aren't useful when used for comparing. You could be right. But knowing only the names of 360 commands by heart is to hart, to me too. I didn't the difference between systemctl and launchctl before.

The fact that 355 commands are not even close to sufficient can be very good. But it should be sufficient for LPIC-1 certification.

Apparently LPIC stands for Linux Professional Institute Certification. You are totally on the wrong track here. If you want to learn Linux, you can install a Virtual Machine like VirtualBuddy and install Linux that way.

For the record, macOS ships with over 1612 command-line tools.

Here are the Apple training offerings: https://training.apple.com/

The Open Group training will get you the parts common to ~all UNIX-compatible systems.

While I’ve used cron and periodic, launchd is usually preferred to cron and crontab. I usually use Lingon app to manage the plist files too, but there are other ways.

i’m not sure why you refer to “Linux knowledge” there, either. macOS is in the BSD part of the UNIX family tree, and is somewhat distant from Linux. Solaris and HP-UX are also distant from macOS, though those are distant in different directions.

com.apple.provenance means the file cleared quarantine. That xattr extended attribute is not relevant to the plist functioning as a plist with launchd.