Description of problem:
The newusers command reads a file and uses this information to update a set of existing users or to create new users. Until now it was not allowed to use any special characters in the username/groupname except a few. But with this release, we have a new option called --badnames that allows us to use special symbols in the usernames/groupnames.

When we execute the newusers command on a file that has special characters in the user/group name, the command fails with an error but there is no suggestion provided to use "--badnames".


Version-Release number of selected component (if applicable):
shadow-utils-4.9-3.el9.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Login as superuser or privileged user
2. Create a file as per the valid syntax for e.g: a file “batchusers” with the following users data:
users@1:users@1:1010:1010:Users 1:/home/users1:/bin/bash
users@2:users@2:1011:1011:Users 2:/home/users2:/bin/bash
3. Execute the command: # newusers batchusers

4. Execute command: # newusers --badnames batchusers

Actual results:
1. The result of step 3 is:
newusers: invalid user name 'users@1'
newusers: line 1: can't create user
newusers: invalid user name 'users@2'
newusers: line 2: can't create user

2. The execution of step 4 results in adding users successfully.

Expected results:
It would be helpful if Step 3 gives a suggestion to use "--badnames" along with the error messages.

Additional info: