Locking down users’ home directories the Debian/Ubuntu way

Debian and its offspring, such as Ubuntu, have two user creation utilities:

• useradd
• adduser

Let’s look at both of them.

useradd on Debian/Ubuntu

The useradd utility is there, but Debian and Ubuntu don’t come with handy preconfigured defaults as the Red Hat-type distros do. If you were to just do sudo useradd frank on a Debian/Ubuntu machine, Frank would have no home directory and would be assigned the wrong default shell. So, to create a user account with useradd on a Debian or Ubuntu system, the command will look something like this:

sudo useradd -m -d /home/frank -s /bin/bash frank

Here’s a breakdown of what all this means:

• -m creates the home directory.
• -d specifies the home directory.
• -s specifies Frank’s default shell. (Without the -s, Debian/Ubuntu would assign to Frank the /bin/sh shell.)

When you look at the...