UNIX for Dummies Questions & Answers

I am just wondering why there are two similar commands for creating a user. Could you please point me when I should choose adduser and when useradd? This puzzles me a little.

Thanks,
Panos

They're the same command, or should be:

Code:

[root@ns1 ~]# ll $(which useradd)
-rwxr-x---. 1 root root 103096 Dec  7  2011 /usr/sbin/useradd
[root@ns1 ~]# ll $(which adduser)
lrwxrwxrwx. 1 root root 7 Jan 26  2013 /usr/sbin/adduser -> useradd

The command to create an account in Linux, at the command line is useradd.
This is the command you are expected to know if you go to pass CompTIA Linux+, LPIC 101 or RHCSA certification.

In some systems it can have more or less "automatic" parameters entered for you using some defaults: like it may or may not create a home for the user, automatically, if you do not provide those parameters.
useradd -D shows the defaults. Some files that it uses for configuration support are /etc/default/useradd and /etc/skel/

On the other hand, adduser is more of a prompted, interactive command, where you are asked for settings if you don't enter it initially. It is a different binary in distros like Ubuntu. However, in distros like Redhat, it is just a link to useradd, so those feature do not exist.

Thanks very much

PS: What Linux distro do you suggest me to use in order to prepare for my LPI exams ?

LPI claims to be "vendor neutral", so it shouldn't matter.

If you do not have LPI 101 already, I recommend CompTIA Linux+ since, at this time, it has a partnership with LPI, which if you pass CompTIA LX0-101 and LX0-102 you will be passing the certification as well for LPI 101 and 102 and you can ask them for both certifications.

In any case, these certifications are vendor neutral, which means you do have to know quite a bit about many things Linux.
For instance, instead of having to know, only, rpm and and yum as in Redhat; with LPI you'll need to know dpkg, and apt-get, as well.

Therefore, you'll need a distribution based in Debian and a distribution based in Redhat, for better results.

RHCSA and RHCE are the next step. Theses exams are real hands on, and there is no multiple choice questions. For these you must configure whatever they ask you in a virtual machine, and the killer is that you must know things very well, including Selinux, because the time allow will be your enemy.

Thanks again guys, you've been extra helpful