Bdtyktl

I have two users, user1 and user2, that are both members of groupA. user2 has a folder in their home directory called folderA. If they wish to allow read-write-execute permissions for all members of groupA, how would they do this?

What if folderA contains many files and additional folders that also need to have read-write-execute permission?

Information regarding groups is a little 'spotty' across the web, so I am putting my question here in the hope someone posts a clear answer that might help others out too.

Thanks!

FolderA will first need to be part of groupA - the folder's owner or root can perform this operation

chgrp groupA ./folderA

Then groupA will need rwx permissions of the folder

chmod g+rwx ./folderA

There are options in the chgrp and chmod commands to recurse into the directory if required.

My own experience in this area here. Original how-to. Tested on Ubuntu 18.04.

Allow to write in the system folder

Give write permission to /etc/nginx/ folder.

# Check 'webmasters' group doen't exist

cat /etc/group | grep webmasters

# Create 'webmasters' group

sudo addgroup webmasters

# Add users to 'webmasters' group

sudo usermod -a -G webmasters username

sudo usermod -a -G webmasters vozman

sudo usermod -a -G webmasters romanroskach



# Group assignment changes won't take effect

# until the users log out and back in.



# Create directory

sudo mkdir /etc/nginx/

# Check directory permissions

ls -al /etc | grep nginx

drwxr-xr-x   2 root root     4096 Dec  5 18:30 nginx



# Change group owner of the directory

sudo chgrp -R webmasters /etc/nginx/

# Check that the group owner is changed

ls -al /etc | grep nginx

drwxr-xr-x   2 root webmasters   4096 Dec  5 18:30 nginx



# Give write permission to the group

sudo chmod -R g+w /etc/nginx/

# Check

ls -al /etc | grep nginx

drwxrwxr-x   2 root webmasters   4096 Dec  5 18:30 nginx



# Try to create file

sudo -u username touch /etc/nginx/test.txt  # should work

sudo -u username touch /etc/test.txt  # Permission denied

Give write permission to /etc/systemd/system/ folder.

# List ACLs

getfacl /etc/systemd/system



getfacl: Removing leading '/' from absolute path names

# file: etc/systemd/system

# owner: root

# group: root

user::rwx

group::r-x

other::r-x



# Add 'webmasters' group to an ACL

sudo setfacl -m g:webmasters:rwx /etc/systemd/system



# Check

getfacl /etc/systemd/system



getfacl: Removing leading '/' from absolute path names

# file: etc/systemd/system

# owner: root

# group: root

user::rwx

group::r-x

group:webmasters:rwx

mask::rwx

other::r-x



sudo -u username touch /etc/systemd/system/test.txt  # should work

sudo -u username touch /etc/systemd/test.txt  # Permission denied