complete-c useradd -s n --description'A group having the same name as the user being added to the system will be created by default (when -g is not specified)'
complete-c useradd -s K -l key --description'Overrides default key/value pairs from /etc/login'
complete-c useradd -s o -l non-unique --description'Allow the creation of a user account with a duplicate (non-unique) UID'
complete-c useradd -s p -l password --description'The encrypted password, as returned by crypt(3)'-r
complete-c useradd -s g -l gid --description'The group name or ID for a new user\'s initial group' -x -a '(string match -r"^[^#].*"< /etc/group |cut-d : -f1,3|string replace -a":"\n)'
complete-c useradd -s s -l shell --description'Name of the new user\'s login shell' -x -a '(string match -r"^[^#].*"< /etc/shells)'