我想写一个关于windows开机输入密码的脚本

铭哥，我想问一下这个脚本运行后，我输错密码10几次的时候会报一个mima.sh: line 6: [: !=: unary operator expected错误，直接弹出，这个是为什么呢？

[root@bogon sbin]# sh password.sh
Please input the password:adf
The password is wrong, retry.
Please input the password:adf
The password is wrong, retry.
Please input the password:adf
The password is wrong, retry.
Please input the password:adfg
The password is wrong, retry.
Please input the password:adfasdf
The password is wrong, retry.
Please input the password:adfgadfa
The password is wrong, retry.
Please input the password:adfadf
The password is wrong, retry.
Please input the password:adfadf
The password is wrong, retry.
Please input the password:adfadf
The password is wrong, retry.
Please input the password:sdew
The password is wrong, retry.
Please input the password:234
The password is wrong, retry.
Please input the password:34454
The password is wrong, retry.

#! /bin/bash

## Writen by Aming!
## Judging for a word if is your password.

pass="nihao123"
while :; do
    read -p "Please input the password:" word
    if [ $word != $pass ]; then
        echo "The password is wrong, retry."
    else
        exit
    fi
done

没有问题呀。只要你输不对是不会退出的。