Shell第三篇：基本语法

#!/bin/bash
var='/etc/init.d'
#var='/dev/sda'
if [ -d $var ]
    then
        echo "$var is directory"
elif [ -b $var ]
    then
        echo "$var is block"
elif [ -f $var ]
    then
        echo "$var is regular file"
else
        echo 'unknow'
fi

#test.sh
echo $0
echo $1
echo $2
echo $3
echo ${11}
echo '$$' $$
echo '$*' $*
echo '$@' $@
echo '$#' $#
echo '$?' $?

'''
测试：python test.sh 1 2 3 4 5 6 7 8 9 10 11
输出结果：
./test.sh
1
2
3
11
$$ 14312
$* 1 2 3 4 5 6 7 8 9 10 11
$@ 1 2 3 4 5 6 7 8 9 10 11
$# 11
$? 0
'''

[root@MiWiFi-R3-srv ~]# cat test_file.sh 
#!/bin/bash
if [ -d $1 ]
    then
        echo "$1 is directory"
elif [ -b $1 ]
    then
        echo "$1 is block"
elif [ -f $1 ]
    then
        echo "$1 is regular file"
else
        echo 'unknown'
fi
[root@MiWiFi-R3-srv ~]# ./test_file.sh /etc/passwd
/etc/passwd is regular file

[root@MiWiFi-R3-srv ~]# cat login.sh 
#!/bin/bashwhile :
do
    read -p 'please input your name: ' name
    read -p 'please input your password: ' pwd
    if [ $name = 'egon' ] && [ $pwd = '123' ]
        then
            echo 'login sucessful'
            break #continue
    fi
done
[root@MiWiFi-R3-srv ~]# ./login.sh 
please input your name: egon
please input your password: 123
login sucessful

[root@MiWiFi-R3-srv ~]# cat 1.sh 
#!/bin/bash
i=1
while ((i<10))
do
    echo $i
    ((i++))
done
[root@MiWiFi-R3-srv ~]# ./1.sh 
1
2
3
4
5
6
7
8
9

[root@MiWiFi-R3-srv ~]# cat 1.sh 
#!/bin/bash

var1=AAA
var2=BBB
var3=CCC
while :
do
    clear
    echo -e "A:${var1}\nB:${var2}\nC:${var3}"
    temp=$var1
    var1=$var2
    var2=$var3
    var3=$temp
    sleep 1
done

[root@MiWiFi-R3-srv ~]# cat 1.sh 
#!/bin/bash
while read var
do
    echo $((++i)):$var
donepasswd

[root@MiWiFi-R3-srv ~]# ./1.sh 
1:root:x:0:0:root:/root:/bin/bash
2:bin:x:1:1:bin:/bin:/sbin/nologin
3:daemon:x:2:2:daemon:/sbin:/sbin/nologin
4:adm:x:3:4:adm:/var/adm:/sbin/nologin
...........

for ((i=1;i<=10;i++))
do
echo $i
done

for i in {1..10}
do
echo $i
done

for i in 1 2 3
for i in {1,2,3}
for i in {1..9}
for i in {9..1}
for i in {a..z}
for i in {A..Z}
for i in {X..Z}
for i in $(cmd)
for i in $(find ...)

    检查内网存活的IP
    #!/bin/bash

    for i in {1..254}
    do
            (ping -W 1 -c 1 192.168.1.$i &> /dev/null && echo 192.168.1.$i) &
    done
    
    
    让文件测试脚本支持多个参数
    #!/bin/bash
    
    for i in $@
    do
      if [[ -d $i ]]
      then
        echo "$i is directory."
      elif [[ -b $i  ]]
      then
        echo "$i is block device."
      elif [[ -f $i ]]
      then
        echo "$i is a regular file."
      else
        echo "unknow."
      fi
    done

#!/bin/bash
echo "script name: `basename $0`"
echo "version 1.0"
echo "date 2017-03-23"
echo "Author: biubiu"
while read -p "(h for help): " var
do
    case $var in 
        p|P|cpu|CPU)
            echo -e "\n\n"
            grep 'model name\|cpu MHz\|processor' /proc/cpuinfo |sort |uniq
            echo -e "\n\n"
        ;;
        m|m|mem|MEM)
            echo -e "\n\n"
            free
            echo -e "\n\n"
        ;;
        d|D|disk|DISK)
            echo -e "\n\n"
            df -Th
            echo -e "\n\n"
        ;;
        h|H|help|HELP)
            echo -e "\n\tcommand\taction\n\n"
            for i in cpu mem disk
            do
            echo -e "\t$i\t${i}_info"
            done
            echo -e "\thelp\tthis help page.."
            echo -e "\tquit\texit !!.."
            echo -e "\n\n"
        ;;
        q|Q|quit|exit)
            exit
        ;;
        *)
            echo -e "\n$var Enter Error...\n"
    esac
done

#!/usr/bin/python
# -*- coding: UTF-8 -*-
import sys
import smtplib
import email.mime.multipart
import email.mime.text

server = 'smtp.163.com'
port = '25'

def sendmail(server,port,user,pwd,msg):
    smtp = smtplib.SMTP()
    smtp.connect(server,port)
    smtp.login(user, pwd)
    smtp.sendmail(msg['from'], msg['to'], msg.as_string())
    smtp.quit()
    print('邮件发送成功email has send out !')


if __name__ == '__main__':
    msg = email.mime.multipart.MIMEMultipart()
    msg['Subject'] = '你是风儿我是沙，缠缠绵绵回我家'
    msg['From'] = 'python4_mail@163.com'
    msg['To'] = 'python4_recvmail@163.com'
    user = 'python4_mail'
    pwd = 'sbalex3714'
    content='%s\n%s' %('\n'.join(sys.argv[1:4]),' '.join(sys.argv[4:])) #格式处理，专门针对我们的邮件格式

    txt = email.mime.text.MIMEText(content, _charset='utf-8')
    msg.attach(txt)

    sendmail(server,port,user,pwd,msg)
                                    

#!/bin/bash
cpu_limit=0 #cpu使用超过90%则报警,此处我们为了得到报警邮件的实验效果，直接设置成0
mem_limit=0 #内存使用超过90%则报警，同上
disk='/dev/sda1' #需要监控的磁盘名
disk_inode_limit=0 #磁盘inode使用超过90%则报警，同上
disk_space_limit=0 #磁盘空间使用超过90%则报警，同上

function monitor_cpu(){
    cpu_free=`vmstat 1 5 |awk 'NR>=3{x = x + $15} END {print x/5}' |awk -F. '{print $1}'`
    cpu_use=$((100-cpu_free))
    if [ $cpu_use -gt $cpu_limit ]
        then
            msg="TIME:$(date +%F_%T)
                 HOSTNAME:$(hostname)
                 IPADDR:$(ifconfig |awk 'NR==2{print $2}')
                 MSG:CPU usage exceeds the limit,current value is ${cpu_use}%"
            echo $msg
            /usr/bin/mail $msg
    fi
}

function monitor_mem(){
    mem_total=`free |awk 'NR==2{print $2}'`
    mem_use=`free |awk 'NR==2{print $3}'`
    mem_per=`echo "scale=2;$mem_use/$mem_total" |bc -l|cut -d. -f2`
    if [ $mem_per -gt $mem_limit ]
        then
            msg="TIME:$(date +%F_%T)
                 HOSTNAME:$(hostname)
                 IPADDR:$(ifconfig |awk 'NR==2{print $2}')
                 MSG:Memory usage exceeds the limit,current value is ${mem_per}%"
            echo $msg
            /usr/bin/mail $msg
    fi
}

function monitor_disk_inode(){
    inode_use=`df -i $disk |awk 'NR==2{print $5}' |cut -d% -f1`
    if [ $inode_use -gt $disk_inode_limit ]
        then
            msg="TIME:$(date +%F_%T)
                 HOSTNAME:$(hostname)
                 IPADDR:$(ifconfig |awk 'NR==2{print $2}')
                 MSG:Disk inode usage exceeds the limit,current value is ${inode_use}%"
            echo $msg
            /usr/bin/mail $msg
    fi
}

function monitor_disk_space(){
    space_use=`df $disk |awk 'NR==2{print $5}'|cut -d% -f1`
    if [ $space_use -gt $disk_space_limit ]
        then
            msg="TIME:$(date +%F_%T)
                 HOSTNAME:$(hostname)
                 IPADDR:$(ifconfig |awk 'NR==2{print $2}')
                 MSG:Disk space usage exceeds the limit,current value is ${space_use}%"
            echo $msg
            /usr/bin/mail $msg
    fi
}

monitor_cpu &>> /tmp/monitor.log
monitor_mem &>> /tmp/monitor.log
monitor_disk_inode &>> /tmp/monitor.log
monitor_disk_space &>> /tmp/monitor.log