linux - 在 bash 中使用命令行创建用户

Question

我想在自定义命令行安装时创建一个用户帐户，下面的代码几乎做得很好:

#!/bin/bash
#nameofuser stands for the new account
#skel is for the a skel folder outside /etc/skel     
if [ $(id -u) -eq 0 ]; then
read -p "Enter username : " nameofuser
read -s -p "Enter password : " password
egrep "^$username" /etc/passwd >/dev/null

 if [ $? -eq 0 ]; then
 echo "$username exists!"
 exit 1

else
pass=$(perl -e 'print crypt($ARGV[0], "password")' $password)
useradd -m -p $pass $nameofuser -c new created user -k $skel
[ $? -eq 0 ] && echo "User has been added to system!" || echo "Failed to add a user!"
fi
else
echo "Only root may add a user to the system"
exit 2
fi

如果输入为空或不符合某些密码规范，我需要第二部分的一些帮助和重新循环。

这是第二部分

我如何确保 if 语句证明了一些东西，例如最小密码长度以及密码是否包含特殊字符和数字或至少包含数字？

如果此检查不符合给定值，如何强制用户重新输入密码？

Answer 1

使用这样的东西:

passwdok=0
while [ $passwdok == 0 ]  ; do
    read -s -p "Enter password : " password
    if [[ ! $password =~ ^.{6,} ]] ; then
        echo "Password should be at least 6 characters"
    elif [[ ! $password =~ [^A-Za-z0-9] ]] ; then
        echo "Password should contain a special character"
    else
        passwdok=1
    fi
done