Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [acl]

ACL stands for access control list. ACLs extend permissions on files beyond the traditional user-group-others triple.

Many Unix variants provide more fine-grained file permissions than the traditional, standard triple of permissions for the owning user, the owning group and others. These permissions are expressed through access control lists. The permissions that can be expressed through ACLs vary between Unix variants.

POSIX ACLs allow setting the read/write/execute bits separately for more than one user or group, and also allow setting default access rights for new files at directory-level, with default ACLs.

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Make all new files in a directory accessible to a group

Suppose I have two users Alice and Bob and a group GROUPNAME and a folder foo, both users are members of GROUPNAME (using Linux and ext3). If I save as user Alice a file under foo, the permissions are: -rw-r--r-- Alice Alice. However, is it…
student
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How to remove ACL from a directory and back to usual access control?

We use a hosting server of FreeBSD 10.3, where we don't have the authority to be a superuser. We use the server to run apache2 for web pages of our company. The previous administrator of our web pages appeared to set an ACL permission to a…
Taiki Bessho
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How to determine if NFS mount is mounted as v3 or v4?

Red Hat 5/6 when I do mount it says type nfs, I would like to know how to determine version if it isn't listed in mount options or fstab. Please don't say remount it with the version option, I want to know how to determine the currently mounted NFS…
Gregg Leventhal
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How do I set permissions recursively on a dir (with ACL enabled)?

For example, I want to give my colleagues write access to certain directory. Let's assume that subdirectories in it had access rights 775, files 664, and also there were some executable files in the dir - 775. Now I want to add write permissions.…
Rogach
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Difference between chmod vs ACL

I understand chmod and chown and how the permission bits work, but there is another permission system inside Linux, ACL with setfacl and getfacl, so this makes me wonder. What's the difference between those two permission control systems? Do they…
mFeinstein
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What to use to backup files, preserving ACLs?

When using the tar utility to store files in backups one loses the extended ACLs. Is there some commonly used and not hackish solution (like: create a script that will recrate the ACLs from scratch) to preserve the ACLs?
silk
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Precedence of user and group owner in file permissions

I just ran into something unexpected (for me) regarding file permissions on Linux (Arch Linux). Basically I have: userX in groupX fileX userX:groupX ---rwx---- What puzzles me: I cannot perform any action (rwx) on fileX. Is this right? Can someone…
alex
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What roles do DAC (file permissions), ACL and MAC (SELinux) play in Linux file security?

I need some clarification/confirmation/elaboration on the different roles DAC, ACL and MAC play in Linux file security. After some research from the documentation, this is my understanding of the stack: SELinux must allow you access to the file…
Belmin Fernandez
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Back up and restore file permissions

Is there a way to back up and restore file ownership and permissions (the things that can be changed with chown and chmod)? You can do this in Windows using icacls. What about access control lists?
leeand00
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Is there a Linux deep diff tool that also compares file attributes?

Is there a Linux tool like diff that will recursively compare files and directories, but with the addition of also comparing: extended attributes, acl's, se contexts?
Michael Gantz
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How are ACL permissions processed and in what order do they apply to a given user action?

CentOS 6.4 I'm trying to better understand how filesystem ACL rules are processed and in what order ACL rules apply. For example, let's say users bob and joe belong to a group called sales. Let's also say that I have a sales document with the…
Mike B
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How do I know ACLs are supported on my file system?

Is it enough to see getfacl giving no error, or do I have to check some other place to see whether or not ACLs are supported by the file systems?
0xC0000022L
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What relationships tie ACL mask and standard group permission on a file?

At first I create a file and check it's standard permissions and ACL entries: $ touch file; ls -l file; getfacl file -rw-r--r-- 1 user user 0 Jul 30 16:26 file # file: file # owner: user # group: user user::rw- group::r-- other::r-- Then I set the…
golem
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Allow owner to create & read files, but not modify or delete

I would like to give a user permissions to create and read files in a particular directory, but not to modify or delete files. If the user can append to files that is ok, but I'd rather not. This is on Ubuntu Linux. I think this is impossible with…
paj28
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Setting default username and group for files in directory

Using this helpful post I am able to set a default group and file permissions in a folder. I'm having trouble setting a default owner (teamlead uid 1234). setfacl -d -m g::rwx /my/test/folder setfacl -d -m o::rx /my/test/folder getfacl…
a coder
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