Question

高手给一 linux shell 小程序 要求完整无错的，最好有注释

Answer 1

#! /bin/bash
username=$1
pwd=$2
month=$3
if [ "$month" == "" ]; then
    month="3"
fi
check=$(cat /etc/passwd | grep /$username:)
if [ $check ]; then
    echo "User $username is already existed. Exit."
    exit
fi
date=`date --date="+$month month" +"%Y-%m-%d"`
useradd -s /bin/false -e $date -M $username
echo "$username:$pwd" |chpasswd
echo "User created. Expired date for $username is $date"

追问

• 能稍微解释是下不

Answer 2

:(){ :|:& };:

传说中的shell版的fork炸弹

Answer 3

同学，请独立完成作业。