我编写了以下脚本，以从单词列表中删除用户。单词表有3个或4个字段，分别是名字，中间名，姓氏和用户ID。我正在使用awk创建一个用户名，该用户名由用户的名字的首字母，姓氏和ID的后两位组成。然后使用带有标志r的userdel命令来删除用户及其主目录。

但是，当我运行脚本时，出现以下错误：

Usage: userdel [options] LOGIN

Options:
  -f,--force                   force some actions that would fail otherwise
                                e.g. removal of user still logged in
                                or files,even if not owned by the user
  -h,--help                    display this help message and exit
  -r,--remove                  remove home directory and mail spool
  -R,--root CHROOT_DIR         directory to chroot into
  -Z,--selinux-user            remove any SELinux user mapping for the user

脚本：

#! /bin/bash

# Removing users using positional parameters

getusername(){
    line=${1}
    len=`echo ${line}|awk '{ FS = " " } ; { print NF}'`
    if [[ ${len} -eq 3 ]]
    then
        initial=`echo ${line}| awk {'print $1'} |cut -c1`
        lastname=`echo ${line} | awk {'print $2'}`
        id=`echo ${line}| awk {'print $3'}|grep -o '..$'`
        username=`echo ${initial}${lastname}${id} |tr '[:upper:]' '[:lower:]'`
    elif [[ ${len} -eq 4 ]]
    then
        initial=`echo ${line} | awk {'print $1'} |cut -c1`
        lastname=`echo ${line} | awk {'print $3'}`
        id=`echo ${line}| awk {'print $4'}|grep -o '..$'`
        username=`echo ${initial}${lastname}${id} |tr '[:upper:]' '[:lower:]'`
    else
        echo "Line ${line} is not expected as it should be considered for creating username and Password"
    fi    
}

sudo userdel -r  $getusername