allow specific user permission to read/write my folder

Question

I have a folder /home/samantha/folder that I want to share with the user tom (he can read, write the folder). How do I do that?

chown wouldn't do it, because I still want to be able to be the owner of the folder... I don't see how to do this with chmod either.

Answer 1

If you are using Linux with a relatively modern filesystem (ext3/ext4, btrfs, ntfs), this can be done with POSIX ACLs:

1. Enable ACLs for the filesystem.

   1. For current session:

      mount -o remount,acl /
      

   2. To make it stay after reboot, add the acl option to the appropriate line in /etc/fstab

2. Give tom access to the folder:

   setfacl -m user:tom:rwx /home/samantha/folder
   

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If the OS or the filesystem does not support ACLs, another way is to use groups.

1. Create a group.

   • Some Linux distributions create a separate group for each user: tom would automatically be in a group also named tom.

   • If not, create a group. This should work on Linux...

     groupadd tom
     gpasswd -a tom tom
     

     ...and this - on BSD:

     groupadd tom
     usermod -G tom tom
     

2. chgrp the directory to that group, and give permissions with chmod:

    chgrp tom /home/samantha/folder
    chmod g+rwx /home/samantha/folder