linux运维、架构之路-shell编程(二)

cat check_mem.sh
#!/bin/sh
Mem=`free -m|awk ‘NR==3{print $NF}‘`
if [ "$Mem" -lt "800" ]
  then
    echo $Mem|mail -s "系统内存低于800M" 774181401@qq.com
fi

#!/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/bash
cat<<EOF
1. install rsync
2. install nfs
3. install mysql
4. install all
5. exit
EOF
read -p ‘请输入你的选择：‘ num

case $num in
  1)
   echo "install rsync suscess!"
   ;;
  2)
   echo "install nfs suscess!"
   ;;
  3)
   echo "install mysql suscess!"
   ;;
  4)
   echo "install all suscess!"
   ;;
  5)
   exit
   ;;
  *)
    echo "选择有误"
esac

#!/bin/sh
RED=‘\E[1;31m‘
GREEN=‘\E[1;32m‘
YELLOW=‘\E[1;33m‘
RES=‘\E[0m‘

cat <<EOF
==================
1.apple
2.pear
3.banana
4.exit
==================
EOF
while true
do
read -p "请输入你喜欢吃的水果：" choice
case $choice in
  1)
    echo -e "你喜欢的水果是： $RED apple $RES"
    ;;
  2)
    echo -e "你喜欢的水果是： $GREEN pear $RES"
    ;;
  3)
    echo -e "你喜欢的水果是：$YELLOW banana $RES"
    ;;
  4)
    exit
    ;;
  *)
    echo "输入有误"
esac
done

#!/bin/sh
Close_Service=`chkconfig|grep 3:on|awk ‘{print $1}‘|egrep -v "crond|network|sshd|rsyslog|sysstat"`
for name in $Close_Service
do
  chkconfig $name off
done

方式一、
exec <file
sum=0
while read line
do
     cmd
done
方式二、
cat ${file_path}|while read line
do
      cmd
done
方式三、
while read line
do
       cmd
done<file

#!/bin/bash
function oldboyedu(){
    echo "Hello world"
    echo $0
    echo $1
    echo $2
    exit
}

etiantian(){
    echo "good"
    return 3
    echo ‘bad‘
}

#oldboyedu hanshu1 hanshu2
oldboyedu $1 $2
etiantian