5

I am reading this Digital Ocean tutorial. In step 1, it says:

We'll need [...] acl to set the right directory permissions when installing the application

I wanted to check if acl is already installed:

$ dpkg -s acl
dpkg-query: package 'acl' is not installed and no information is
available Use dpkg --info (= dpkg-deb --info) to examine archive
files, and dpkg --contents (= dpkg-deb --contents) to list their
contents.

Then my logic tells me to look for it with apt-cache search, and I run apt-cache search acl; it returns a list of packages, but I don't see one named strictly acl.

After some investigation I found similar questions on SO, here and there.

I try: apt-cache policy acl. It returns:

acl:   
   Installed: (none)   
   Candidate: 2.2.52-3   
   Version table:
     2.2.52-3 500
     500 https://mirrors.gandi.net/ubuntu xenial/main amd64 Packages

So I guess it means that is alright acl is installed.

I don't understand, since it seems installed when I do apt-cache policy acl why dpkg -s acl returns that it is not installed?

I've read something that I don't understand in there in the apt-cache command doc:

apt-cache policy displays the priorities of package sources as well as those of individual packages

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nyluje
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2 Answers2

8

The acl package provides commands for manipulating ACLs, however the actual support for ACLs is provided by libacl1 and the filesystems implementing ACLs. The commands are entirely optional, since applications like systemd can use the library instead.

Installed: (none) means the package is not installed. Go ahead and install it:

sudo apt-get install acl
muru
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4

Out of these SO thread I try: apt-cache policy acl. It returns:

acl: Installed: (none) Candidate: 2.2.52-3 Version table: 2.2.52-3 500 500 https://mirrors.gandi.net/ubuntu xenial/main amd64 Packages

So I guess it means that is alright acl is installed.

The result of the command showed that the version of acl installed on your computer is none

Which means that acl is not installed on your computer.

When you'll execute the same command on a machine with installed version of acl you'll get something like:

 apt-cache policy acl
acl:
  Installed: 2.2.52-3
  Candidate: 2.2.52-3
  Version table:
 *** 2.2.52-3 500
        500 http://.......com/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status
Yaron
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