Is user in dialout group?

Question

In my script I need to find out whether user is in dialout group and if he is not, add him to the group. I have found out how to add him but is there a way how to know if he is in the group ?

Answer 1

You can do this in both ways:

• Check all groups a specific user is member of and check if dialout is there:

  id username
  

  Or as Wolf said already:

  groups username
  

• Check all members of the specific group (dialout) and check if the user is in the list:

  getent group dialout
  

Answer 2

You are looking for the groups command. Here's an example of me using it on a server I just happened to be talking to at the moment (I'm logged in as the lprod user):

[lprod@milazgit01 ~] $ groups wolf
wolf : prod tools

Then you can compare that to a regular expression in whatever shell you are using.