Centos usermod -a 不添加用户到组

Question

In my project i have to create a group on my centos server and add two users; i do:

sudo groupadd editorial

then i try to add my two users to group like this:

sudo usermod -a -G editorial nginx
sudo usermod -a -G editorial ec2-user

ok, no errors, but when i check my group:

sudo groups editorial

in output i get:

groups: editorial: no such user

why i cannot add my user to group?

Thanks in advance

Answer 1

愚蠢的问题..但是在尝试 usermod 之前你做过“$sudo useradd nameofuser”吗？

Answer 2

Your form of the command is wrong. You separate the supplemental groups with commas not whitepsace , man usermod:

-G A list of supplementary groups which the user is also a member of. Each 
   group is separated from the next by a comma, with no intervening whitespace.

Example:

sudo usermod -a -G editorial,nginx nameofuser

And this questions is somewhat a close call, if you are writing a script to do this, then that is probably OK on StackOverflow, but if this is just a general "How do I use usermod ", that should probably go to Super User or Unix & Linux