Execute the command sudo useradd --help

The error is reported as follows:
fuyun is not in the sudoers file. This incident will be reported.

Reason: the user does not have root permission temporarily

Solution: modify sudoers file
Switch to the root user, su -, run the visudo command, which is used to edit and modify the / etc/sudoers configuration file.

visudo
As shown in the figure below, add user name, ALL=(ALL), nopasswd in the following location: all

## Allow root to run any commands anywhere
root    ALL=(ALL)       ALL
fuyun   ALL=(ALL)       NOPASSWD:ALL

Note: if NOPASSWD: is not added, the password of root account is required for every sudo.

Test:
Execute the command exit to exit the root account
Execute the first command of the article again

[fuyun@bigdata-training hive-3.1.1]$ sudo useradd -help
useradd: invalid option -- 'h'
Usage: useradd [options] LOGIN

Options:
  -b, --base-dir BASE_DIR       base directory for the home directory of the
                                new account
  -c, --comment COMMENT         GECOS field of the new account
  -d, --home-dir HOME_DIR       home directory of the new account
  -D, --defaults                print or change default useradd configuration
  -e, --expiredate EXPIRE_DATE  expiration date of the new account
  -f, --inactive INACTIVE       password inactivity period of the new account
  -g, --gid GROUP               name or ID of the primary group of the new
                                account
  -G, --groups GROUPS           list of supplementary groups of the new
                                account
  -h, --help                    display this help message and exit
  -k, --skel SKEL_DIR           use this alternative skeleton directory
  -K, --key KEY=VALUE           override /etc/login.defs defaults
  -l, --no-log-init             do not add the user to the lastlog and
                                faillog databases
  -m, --create-home             create the user's home directory
  -M, --no-create-home          do not create the user's home directory
  -N, --no-user-group           do not create a group with the same name as
                                the user
  -o, --non-unique              allow to create users with duplicate
                                (non-unique) UID
  -p, --password PASSWORD       encrypted password of the new account
  -r, --system                  create a system account
  -s, --shell SHELL             login shell of the new account
  -u, --uid UID                 user ID of the new account
  -U, --user-group              create a group with the same name as the user
  -Z, --selinux-user SEUSER     use a specific SEUSER for the SELinux user mapping

No longer reported wrong