Access Control List Support

Sean Harmer sean.harmer1 at
Sun May 22 13:23:44 BST 2005

Hi all,

I doubt that anybody noticed a the importing of a little application into 
playground/base earlier this week that starts to address the support of POSIX 
ACLs in KDE.

I deliberately kept it quiet as I wanted to do some more work on it first. 
I've just made another commit which enables the read-only functionality for 

Anyway, here goes...

The program is called acldlg and lives in trunk/playground/base. I only expect 
this to stand a chance of working on linux at the moment. The program should 
be lauched from the command line. As arguments it expects a list of files 
and/or directories. e.g.

acldlg file1 file2 dir1 dir2

It will then read the Access and Default ACLs on these items and display a 
representation of them in a dialog - see attached screen shot.

There are many cases that such a utility needs to handle. Such as:

All files contain an acl entry: These are displayed in normal text.

Only some files contain an acl entry: These are displayed in italic text.

An acl entry of the same type and qualifier exists on different files but they 
have different parmissions: The perms that appkly to only a subset are shown 
with a hollow tick mark, those that apply to all files are shown witha filled 
tick mark. Also the calculated effective rights are displayed so that those 
permissions that apply to only a subset of the selected files are in capital 
letters. This is similar to what the chmod utility does with its +X option.

The dialog will reflect changes made to existing ACL entries. At the moment 
this is only possible by clicking on the tick marks to toggle their perms. 
Eventually I'll add a dialog that will be hooked up to the "Modify" button.

The Delete ACL button will function slightly differently depending upon which 
ACL is currently selected. For an Access ACL it will delete all of the 
extended acl entries, ie those of type ACL_USER and ACL_GROUP. For a Default 
ACL, it will delete the entire ACL.

Do not worry about accidentally messing up any ACLs as none of your changes 
will be applied. There's even an apply button yet  :-)

Please test this little utility if you get a chance and give me some feedback. 
It's quite important that we get this right as many businesses require ACL 
support from a desktop environment.

Eventually I hope to integrate this into KIO.

Many thanks,

Sean Harmer
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