Technically, this is also possible by creating extra groups, but this kind of access control presumably exists because the old-school method can be a pain to administer. Choosing group names can also be an "interesting" secondary challenge.
i.e. Dude's not going to be best pleased if they ls -l and see the group on the file is xyzgroup-but-not-dude even if it is with good reason. (Shouldn't have deleted the database, dude.)
I don't really think that that's a realistic goal for ACLs. I mean, getfacl showing the user specifically being excluded probably isn't any more-polite.
Confusing. You set a mask for a user and somehow it propagated down to a group and then you change permission on that group suddenly it applies to the user? Either something is wrong here or ACL permissions make absolutely zero sense. It is 5 billion times easier to use normal permissions to set these things up.
I think it's like this: what used to be group in regular permissions output is a union of group and ACL mask in ACL output. Mask sets the upper limit of what ACL can do, so if mask is rw- then it's impossible to set a r-x ACL permission because allowing execution is not allowed.
This seems to be more geared towards enterprise environment where it could be complicated to cleanly define groups, since you can only give access to one you might run into a problem where dept. A needs access to that directory but also person G from dept. B and person K from dept. C.
Cool, I didn't know ACLs were a widely available thing but the infographic explains pretty well! Sounds really useful when granular controls are needed, but I could also imagine it being a huge pain in environments already built out and scripted around regular permissions. Still as always, options are good and an ounce of planning is worth a pound of troubleshooting.
I do low-key hate seeing a directory named "dir" and a group named "me" though. That's chaotic neutral shit at the very least.
Permissions are listed as "user", "group", "other". I.e. the user who made the file, the group of the user who made the file (usually just their name as a group), and everyone else. In this case the rxw is for the user.
For chmod, you can also represent these as binary numbers: 111 would mean having all 3, 101 would mean having read and write, etc. These binary numbers then get turned back into regular numbers (7 in the first example, since it's 111) for chmod. Giving a file "chmod 777" means the user, group, and other all have full permissions on the file. "chmod 700" gives the creator full control, but no one else can view, modify, or execute the file.
Network ACLs are my bane. Someone long ago decided we needed to "isolate" the network, so they put ACLs everywhere and so now 50% of my teams time is spend fucking with ACLs :/ It's awful.