linux运维、架构之路-shell编程(一)

[root@nfs-server ~]# env
HOSTNAME=nfs-server
TERM=linux
SHELL=/bin/bash
HISTSIZE=1000
SSH_CLIENT=172.19.5.146 49184 22
SSH_TTY=/dev/pts/1
USER=root
……

 /etc/profile  /etc/bashrc  ~/.bashrc ~/.bash_profile

 /etc/profile.d

devPath=/server/scripts
devFileList=`ls`

echo ${week}day

x=10
file=/etc/hosts
注：脚本中能用变量的地方尽量就用变量

$0 $1 ... $n $#
注：此方式脚本更加灵活

[root@zabbix scripts]# sh atm.sh 请输入你的银行卡：18774499487766 请输入你的密码：765689 你的银行卡 18774499487766 “你的密码” 765689

OLDBOY="I am oldboy"
echo ${#OLDBOY}

[root@web01 ~]# OLDBOY="I am oldboy"
[root@web01 ~]# echo ${OLDBOY:2}
am oldboy
[root@web01 ~]# echo ${OLDBOY:2:2}
am
[root@web01 ~]# echo ${OLDBOY:5}
oldboy

#从前往后
oldboy=abcABC123ABCabc
[root@web01 scripts]# echo ${oldboy#abc}
ABC123ABCabc
[root@web01 scripts]# echo ${oldboy##a*c}
#从后往前
[root@web01 scripts]# echo ${oldboy%abc}
abcABC123ABC
[root@web01 scripts]# echo ${oldboy%%a*c}

[root@web01 ~]# OLDBOY=abcABC123ABCabc
[root@web01 ~]# echo ${OLDBOY/123/456}
abcABC456ABCabc
[root@web01 ~]# echo ${OLDBOY/a/A}
AbcABC123ABCabc
[root@web01 ~]# echo ${OLDBOY//a/A}
AbcABC123ABCAbc

[root@web01 scripts]# i=0
[root@web01 scripts]# echo $((i++))
0
[root@web01 scripts]# echo $((i++))
1
[root@web01 scripts]# echo $((i--))
4
[root@web01 scripts]# echo $((i--))
3

[root@web01 ~]# i=1
[root@web01 ~]# let i=i+8
[root@web01 ~]# echo $i
9

[root@web01 ~]# expr 3 - 2
1
[root@web01 ~]# expr 1 + 2
3
[root@web01 ~]# expr 2 - 1
1
[root@web01 ~]# expr 1 + a
expr: 非整数参数
[ echo $? -eq 2 ]时，不是整数

[root@web01 ~]# echo 1+1|bc
2
[root@web01 ~]# echo 2*2|bc
4

[root@web01 ~]# echo "5.4 4.3"|awk '{print ($1-$2)}'
1.1

[root@web01 scripts]# crontab -l|tail -2
#check free Mem
*/3 * * * * /bin/sh /server/scripts/check_mem.sh &>/dev/null

#!/bin/sh
. /etc/init.d/functions
Nginx_Start="/application/nginx/sbin/nginx"
Nginx_stop="${Nginx_Start} -s stop"
if [ "$1" == "start" ]
  then
    ${Nginx_Start}
    action "starting Nginx" /bin/true
elif [ "$1" == "stop" ]
  then
    ${Nginx_stop}
    pkill nginx
    action "Nginx is stopped" /bin/true
elif [ "$1" == "restart" ]
  then
    ${Nginx_stop} && ${Nginx_Start}
   action "Nginx is restarting" /bin/true
elif [ "$1" != "start" -a "$1" != "stop" -a "$1" != "restart" ]
  echo "USAGE: $0 {start|stop|restart}"
fi

#!/bin/sh
. /etc/init.d/functions
port=`lsof -i:80|grep nginx|wc -l`
if [ $port -ge 2 ];then
  action "Nginx is running" /bin/true
else 
  action "Nginx is not running" /bin/false
  /application/nginx/sbin/nginx
  action "starting Nginx" /bin/true
fi

#!/bin/sh
rm -f /tmp/user.log
for n in `seq 3`
do
  pass=`echo $RANDOM|md5sum|cut -c 1-8`
  #grep "user$n" /etc/passwd &>/dev/null
  id user$n &>/dev/null
  if [ $? -ne 0 ];then
    useradd user$n
    echo $pass|passwd --stdin user$n
    echo -e "user: user$n pass: $pass" >>/tmp/user.log
  else
        echo "user$n 已存在"
    exit
  fi
done

#!/bin/sh
. /etc/init.d/functions
port=`ps -ef|grep nginx|grep -v grep|wc -l`
if [ $port -ge 2 ];then
  action "Nginx is running" /bin/true
else 
  action "Nginx is not running" /bin/false
  /application/nginx/sbin/nginx
  action "starting Nginx" /bin/true
fi

#!/bin/sh
. /etc/init.d/functions
port=`wget -T 5 --spider http://172.19.5.8 &>/dev/null`
if [ $? -eq 0 ];then
  action "Nginx is running" /bin/true
else 
  /application/nginx/sbin/nginx
  action "starting Nginx" /bin/true
fi

#!/bin/sh
. /etc/init.d/functions
port=`curl -s -I -w "%{http_code}\n" 172.19.5.8 -o /dev/null`
if [ "$port" == "200" ];then
  action "Nginx is running" /bin/true
else 
  /application/nginx/sbin/nginx
  action "starting Nginx" /bin/true
fi

字体颜色设置： echo -e "\033[30m 黑色字oldboy trainning \033[0m" echo -e "\033[31m 红色字oldboy trainning \033[0m" echo -e "\033[32m 绿色字oldboy trainning \033[0m" echo -e "\033[33m 黄色字oldboy trainning \033[0m" echo -e "\033[34m 蓝色字oldboy trainning \033[0m" echo -e "\033[35m 紫色字oldboy trainning \033[0m" echo -e "\033[36m 天蓝字oldboy trainning \033[0m" echo -e "\033[37m 白色字oldboy trainning \033[0m" 背景颜色： echo -e "\033[40;37m 黑底白字 welcome to old1boy\033[0m" echo -e "\033[41;37m 红底白字 welcome to old2boy\033[0m" echo -e "\033[42;37m 绿底白字 welcome to old3boy\033[0m" echo -e "\033[43;37m 黄底白字 welcome to old4boy\033[0m" echo -e "\033[44;37m 蓝底白字 welcome to old5boy\033[0m" echo -e "\033[45;37m 紫底白字 welcome to old6boy\033[0m" echo -e "\033[46;37m 天蓝白字 welcome to old7boy\033[0m" echo -e "\033[47;30m 白底黑字 welcome to old8boy\033[0m" 关闭颜色\033[0m

[root@zabbix scripts]# sh chkconfig.sh [root@zabbix scripts]# chkconfig|grep 3:on crond 0:off    1:off    2:on    3:on    4:on    5:on    6:off network 0:off    1:off    2:on    3:on    4:on    5:on    6:off rsyslog 0:off    1:off    2:on    3:on    4:on    5:on    6:off sshd 0:off    1:off    2:on    3:on    4:on    5:on    6:off sysstat 0:off    1:on     2:on    3:on     4:on   5:on    6:off