Linux – How to create linux account with useradd without creating mail spool

linuxuser-accounts

Summary

Can I create a new user without creating mail spool and without modification of /etc/default/useradd ?

Explaination

I want to create a user that has a home directory and skeletion, but I don't want the useradd script to add a mail spool file to the unix system.

My /etc/default/useradd file states that

CREATE_MAIL_SPOOL=yes

but I don't want to modify the default behaviour.

For now I'm using

useradd nomailuser
rm /var/spool/mail/nomailuser

Also I know about -d but it seems that I can't find an option for not creating a mail spool.

I'm thinking about is there an option to use custom /etc/default/useradd file.

Best Answer

man useradd

   -K, --key KEY=VALUE
       Overrides /etc/login.defs defaults (UID_MIN, UID_MAX, UMASK, PASS_MAX_DAYS and others).

       Example: -K PASS_MAX_DAYS=-1 can be used when creating system account to turn off password ageing, even though
       system account has no password at all. Multiple -K options can be specified, e.g.: -K UID_MIN=100 -K UID_MAX=499

So, try this:

# useradd -K MAIL_DIR=/dev/null nomailuser

A warning would appear (Creating mailbox file: Not a directory), but you can ignore.

Related Solutions

Linux – create home directories after create users

This might sound like a silly idea, but if the users aren't actually doing anything, you could do:

cat /etc/passwd | cut -f 1 -d : >/tmp/users.list

Then edit /tmp/users.list to only contain the users you want. Then do:


for i in `cat /tmp/users.list`
do
    userdel $i
    useradd -m $i
done

However, many Redhat based distributions will create you a new home directory when you first login, providing it is specified in /etc/passwd where the directory should be.

To test that, do an "su - " and see if it does "the right thing". If it doesn't, the above script will work quite nicely, I think.

Linux Usernames – What Characters to Use or Avoid in Linux Usernames

My advice to you is to follow the standard recommended by the default NAME_REGEX. You can actually put nearly anything in a user name under *NIX but you may encounter odd problems with library code that makes assumptions. Case in point:

https://web.archive.org/web/20170928165345/http://blog.endpoint.com/2008/08/on-valid-unix-usernames-and-ones-sanity.html

My question to you: do you have a lot of domain names that would collide with each other if you stripped out the unusual punctuation? For example, do you have both "QUALITY-ASSURANCE" and QUALITYASSURANCE" as domain names? If not, you could simply adopt a policy of stripping out the unusual characters and using what's left as the user name.

Also, you could use the "real name" section of the GECOS field in the /etc/passwd information to store the original, unmodified domain name, and scripts could extract it pretty easily.

Best Answer

Related Solutions

Linux – create home directories after create users

Linux Usernames – What Characters to Use or Avoid in Linux Usernames

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