批量添加删除用户脚本

#!/bin/bash
#
#本脚本用于批量添加/删除用户，用户初始密码是123456，首次登陆需要修改密码
#格式：./class_stu.sh 参数1 参数2 参数3
# 参数1：起始用户名，为纯数字编号，长度必须大于6
# 参数2：添加人数[0-999]
# 参数3：操作：1-添加，2-删除
#例：./class_stu.sh 2009034201 30 1 表示添加从2009034201开始的30个帐号
#    ./class_stu.sh 2009034201 30 2 表示删除从2009034201开始的30个帐号  
#class_stu.sh
#2011-8-21 LOPN
export PATH=/bin:/sbin:/usr/bin:/usr/sbin
function error()
{
 echo "*****ERROR: the format is : ./class_stu.sh par1 par2 par3"
 echo "*****EXAMPLE:class_stu.sh 2009034201 30 1"
 echo "*****NOTICE:par1 must is number and the length must rather 6"
 echo "*****NOTICE:par2 meanings the number of you want add[0-999]"
 echo "*****NOTICE:par3 respect your choice-add or del:"
 echo "****   1:add memeber  ***********"
 echo "****   2:del memeber  ***********"
 echo "******************Other number is illegal********************"
 
}
if [ $# != 3 ]
then
 error
 exit 1
fi
reciveinit1=`echo $1 | grep -e "^[0-9]\{6,\}$"  `
reciveinit2=`echo $2 | grep -e "^[0-9]\{1,3\}$" `
operater=`echo $3 | grep -e "^[0-9]$"` 
if [ "$1" != "$reciveinit1" ] || [ "$2" != "$reciveinit2" ] || [ "$3" != $3 ]
then
 error
 exit 1
fi

initaccount=$1
curaccount=$initaccount
i=0
case $3 in
1)
 echo "***************************ADD USER********************************"
 echo -n "Are you ensure to add?[y|Y/n|N]"
 read yes
 if [ "$yes" == "y" -o "$yes" == "Y" ]
 then
  while [ "$i" != "$2" ]
  do
   echo "**********ADD USER $curaccount **********"
   ifexist=`cat /etc/passwd | awk -F : "{print \\$1}" | grep $curaccount`
   if [ "$ifexist" == "$curaccount" ]
   then
    echo "***********THE USER  $curaccount ALREADY EXISTS!*********"
    echo "********************NEXT*********************"
   else
    useradd $curaccount
    echo "123456" | passwd --stdin $curaccount
    chage -d 0 $curaccount
    echo "*******THE USER $curaccount HAS BEEN ADD ! OK***********"
   fi
   i=$(($i+1))
   curaccount=$(($curaccount+1))