批量删除用户【指定ID】

#!/bin/bash
UserId=$1
UserIdEnd=$2
UserData="/etc/passwd"
Nulls="/dev/null"
#echo $UserId
#echo `expr $UserId + 1`
#`expr $UserId + 1 >$Nulls 2>&1`
if [[ -z $UserId ]] || [[ `expr $UserId + 1 >$Nulls 2>&1`$? -ne 0 ]];then
	echo $?
	echo "请传入合法的参数，必须是整数！"
	exit
fi
if [ -z $UserIdEnd ];then
	UserIdEnd=`awk -F":" 'END{print $3}' $UserData`
fi
echo "开始ID "$UserId
echo "结束ID "$UserIdEnd
if [ $UserIdEnd -gt $UserId ];then
	for ((i=$UserId;i<=$UserIdEnd;i++))
	do
		UserName=`awk -F":" '/:'$i':/{print \$1}' $UserData`
		#echo "awk -F\":\" '/$i/{print \$1}' $UserData"
		echo "正在删除："$i"-----"$UserName
		userdel -r $UserName >$Nulls 2>&1
	done
fi