▲就业班和全程班的小伙伴看这里：（学习老王视频的作业第7-8节）
1、统计出/etc/passwd文件中其默认shell为非/sbin/nologin的用户个数，并将用户都显示出来
[root@centos7 ~]#getent passwd|grep -v "/sbin/nologin$" | sed -nr 's@^([^:]+):.*$@\1@p' | cat -n
1 root
2 sync
3 shutdown
4 halt
5 chen
2、查出用户UID最大值的用户名、UID及shell类型
[root@centos7 ~]#getent passwd|sort -nr -t":" -k3|head -1|cut -d":" -f1,3,7
nfsnobody:65534:/sbin/nologin
3、统计当前连接本机的每个远程主机IP的连接数，并按从大到小排序
[root@centos7 ~]#netstat -net|egrep [0-9]|tr -s " " :|cut -d: -f6|sort |uniq -c|sort -nr
4、编写脚本 createuser.sh，实现如下功能:使用一个用户名做为参数，如果 指定参数的用户存在，就显示其存在，否则添加之;显示添加的用户的id号等 信息
[root@centos7 /data/scripts]#vim useradd.sh
#!/bin/bash
set -u
set -e
read -p "Please input you want add username:" NAME
if [ -z $NAME ] ; then
echo "Usage:Need USERNAME"
exit 10
elif id $NAME &> /dev/null; then
echo "User $NAME is exist"
exit 20
elif useradd $NAME &>/dev/null; then
echo $NAME is created ; echo abc.123 | passwd --stdin $NAME &> /dev/null ; passwd -e $NAME &>/dev/null
echo $NAME uid is `getent passwd|grep "$NAME"|sed -nr 's/.*:([0-9]+):.*/\1/p'`
else
echo " Error! "
fi
:wq
[root@centos7 /data/scripts]#useradd.sh
Please input you want add username:rick
rick is created
rick uid is 1001
5、编写生成脚本基本格式的脚本，包括作者，联系方式，版本，时间，描述等
[root@centos7 ~]#vim .vimrc
autocmd BufNewFile *.sh exec ":call SetTitle()"func SetTitle()
if expand("%:e")=='sh'
call setline(1,"#!/bin/bash")
set tabstop=4
set softtabstop=4
set shiftwidth=4
set expandtab
set ignorecase
set cursorline
set autoindent
autocmd BufNewFile *.sh exec ":call SetTitle()"
func SetTitle()
if expand("%:e")=='sh'
call setline(1,"#!/bin/bash")
call setline(2,"#")
call setline(3,"#*****************************************************************")
call setline(4,"#Author: chenyb")
call setline(5,"#Date: ".strftime("%Y-%m-%d"))
call setline(6,"#FileName: ".expand("%"))
call setline(7,"#Description: The test script")
call setline(8,"#Copyright (C): ".strftime("%Y")."All rights reserved")
call setline(9,"#*****************************************************************")
call setline(10,"")
endif
endfunc
autocmd BufNewFile * normal G
:wq
