Symbolic vs Absolute

[jmkmx]

Hello forum,

I am currently learning how to use the chmod command, now my question would be, when using the Symbolic Mode is there a way to set permissions separately like you do with the Absolute mode?

e.g.

sudo chmod 777 filename

With this I am granting rights individually to all; user, group and others but I don't know how to do the same with the Symbolic mode, lets just say I want to give rwx rights to the group but at the same time I want to revoke all rights for others.

I know I can do the following but I'm not sure if I would need to run the command a second time to achieve what I am trying to do.

chmod go +wrx filename

[Dennis N]

You can do it all in one command

:
chmod g+rwx,o-rwx filename

You can also use = to set permissions:

chmod g=rw,o=r filename

with = any permission not specified is removed if present. So g loses x, and o loses w and x

[jmkmx]

Awesome, I appreciate the extra tip right at the bottom... Thank you very much my friend!

[ActionParsnip]

Please mark as solved if the issue is sorted, or add more detail and we can assist more

[jmkmx]

Sorry, I had no idea this was a thing, it is done now, I have another post, let me go mark it as resolved as well...

[jmkmx]

I have one more question regarding the same subject...

When removing the SUID or GUID in symbolic mode I would do the following:

sudo chmod ug-s filename

But when I try to do the same while using the absolute mode, only the SUID gets removed for some reason while GUID stays in place.

e.g.

sudo chmod 0755 filename

What would be the proper command to remove the GPUI or both of them at the same time in the absolute mode?

[Dennis N]

What would be the proper command to remove the GPUI or both of them at the same time in the absolute mode?

Here's an example, setting and unsetting:

Original file:

[dmn@Tyana testing]$ ls -l
total 0
-rw-r--r-- 1 dmn dmn 0 Sep  6 13:45 myfile.txt

Set SUID and GUID:
[dmn@Tyana testing]$ chmod 6644 myfile.txt
[dmn@Tyana testing]$ ls -l
total 0
-rwSr-Sr-- 1 dmn dmn 0 Sep  6 13:45 myfile.txt

reverse it:
[dmn@Tyana testing]$ chmod 644 myfile.txt
[dmn@Tyana testing]$ ls -l
total 0
-rw-r--r-- 1 dmn dmn 0 Sep  6 13:45 myfile.txt

as it originally was.

[jmkmx]

Ah I see, you don't really need to specify, just set the original values, interesting, once again thank you very much!

[Dennis N]

Ah I see, you don't really need to specify, just set the original values, interesting, once again thank you very much!

You got it. This is an advantage of the 'absolute' (numerical) notation. No adding or subtracting involved.