1.自动判断用户是否存在并添加用户和设置密码，并显示当前系统的用户数并列出可以登录的普通用户。

#!/bin/bash

#Author BY sysk

#DATE 2015/08/13

NAME=$1

#判断传递参数是否合格

if [ $# -lt 1 ]; then

echo -e "\033[32m "You should use it such as: ./addusers arg" \033[0m"

exit 6

fi

if id $NAME ; then

echo "$NAME exists."

else

useradd $NAME

echo "$NAME"| passwd --stdin $NAME

echo "ADD $NAME finished."

fi

#去除系统保留帐号

USERS=`cat /etc/passwd |cut -d: -f1 |grep -v 'bin\|daemon\|adm\|lp\|sync\|shutdown\|halt\|mail\|uucp\|operator\|games\|gopher\|ftp\|nobody\|dbus\|usbmuxd\|vcsa\|rtkit\|avahi-autoipd\|abrt\|gdm\|ntp\|apache\|saslauth\|postfix\|pulse\|sshd\|tcpdump\|mysql'`

TOTAL=`echo -e "$USERS" |wc -l`

echo -n "The current number and users of the system is:"

echo -e "\033[32m "$TOTAL" \033[0m"

echo -e "\033[31m $USERS \033[0m"

 

 

2.ping局域网内所有主机在线状态

#!/bin/bashfor I in `seq 1 254`;do       ping -c 1 -W 1 172.17.1.$I &>/dev/null && echo "172.17.1.$I is up" ||  echo "172.17.1.$I is down"       done