How come useradd isn't working?

Question

I'm trying to work out the kinks for this RPM I'm trying to create. Basically, I'm trying to make it so that if mark does not exist on the system, I want to create a mark user account. I've got this in a %pre block in my .spec file:

id mark &>/dev/null
if [ "$?" != "0" ]; then
    echo "Adding 'mark' user..."
    useradd -g $GROUP_ID \
        -s /bin/bash -d mark
fi

Now, after I build the RPM and run rpm -ivh iPackage-1.0.0-1.noarch.rpm, I check the output and see "Adding 'mark' user...", but when I run id mark on the command line, I get id: mark: No such user. Also, /etc/passwd doesn't have a mark account, either. Any ideas?

Edit: See my answer. Turns out, the variables need to be defined.

Answer 1

In my distro useradd should be invoked like this:

# useradd -ms /bin/bash mark

Use -m if you want to create the home directory (see man useradd).

Also as Matt H said, fix that space.

Answer 2

I'm a moron. I had a &2>/dev/null in my code, so I wasn't seeing my errors. After fixing that, I found out that a variable I was using wasn't defined for the -g switch of useradd.

I've edited the question to further demonstrate what I was doing.

Answer 3

useradd must be run as root.

I don't use an RPM-based Linux, but I guess your pre-install script is running as an under-privileged user.