Sharing uid/gid between multiple Linux users

Source: Dev.to

Sharing uid/gid between multiple Linux users

It’s possible to create multiple users and groups that share the same UID/GID. While this can be confusing, there are scenarios where it’s useful.

Groups

To have two groups share the same GID, edit the following files:

• /etc/group
• /etc/group-
• /etc/gshadow

Add a new line that mirrors the original group line, changing only the group name. For example, given the original line:

group:bill.gates:x:1000:bill.gates

Create a new line:

group:bill.fences:x:1000:bill.gates

After saving the files, both bill.gates and bill.fences will have gid=1000 and will include the same user bill.gates.

Users

The same approach applies to users. Modify these files:

• /etc/passwd
• /etc/passwd-
• /etc/shadow

Add a new entry that duplicates the original user line, changing only the username. Be mindful of the order of entries: the first matching line for a given UID is typically the one that applications will display.

Note: Some applications that work with UIDs may only show the first username that matches the UID.