Shell脚本编程示例大全

2019-07-08
Development
Programming

Shell脚本编程示例大全

2019-07-08

[TOC]

0x00 基础案例

示例1.变量叠加与单双引i号得异同

#!/bin/bash
x=123
y="$x"456
y=${y}789 
echo -e "y=\e[1;32m $y \e[0m"  #y=123456789

z='$y'   # 单引号 不能引用变量 'character':表示字符串  #$y
a="$y"   # 双引号 引用变量 特殊符号有特殊意义 \\ \n  #123456789

b="$x"
c='"$x"'    #不能被解析变量
echo -e "z=\e[1;37m '$z' $a \e[0m"  #z = '$y' 123456789
echo -e "$c=\e[37;1;5m $b \e[0m"   #$x = 123

示例2.五种计算方法Method

#!/bin/bash
va=$1
vb=$2
echo -e "输入的参数:$va,$vb \n"

## [] 方式，无操作符号无空格影响，括号里面的数值变量无需$
echo -e "\e[1;36m #Method 1 '$[exp]' \e[0m"
echo "va+vb=$[$va+$vb]"

## (()) 方式，无操作符号无空格影响，括号里面的数值变量无需$
echo -e "\n\e[1;35m #Method 2 '$((exr))' \e[0m"
echo "va+vb=$(($va+$vb))"

## let 方式，操作符号的变量两边无需空格，且里面的数值变量无需$
echo -e "\n\e[1;34m #Method 3 'let x=1+1' \e[0m"
let vc=$va+$vb
echo "va+vb=$vc"

## expr 方式，非常注意表达式两边的空格,里面的数值变量必须加上$
echo -e "\n\e[1;33m #Method 4 'expr 1 + 1' \e[0m"
result=`expr $va + $vb` #注意加号两边的空格
echo "va+vb=$result"

## declare 方法，操作符号两边无需空格，且里面的数值变量必须加上$
echo -e "\n\e[1;32m #Method 5 'declare -i x=1+1' \e[0m"
declare -i vd=$va+$vb
echo "va+vb=$vd"

## 自加自减
a=10; ((a++));  echo ${a}  # 11
b=10; ((b--));  echo ${b}  # 9

示例3.精密计算之小数计算

#!/bin/bash
echo -e "\e[1;32m #精密计算bc\e[0m"

a=$1
b=$2
echo "bc精密计算a=:`echo "$a"|bc`"
echo -e "bc精密计算b=:`echo "$b"|bc` \n"

echo "bc精密计算a+b=:`echo "$a+$b"|bc`"
echo "bc精密计算a/b=:`echo "$a/$b"|bc`"
echo -e "bc精密计算a*b=:`echo "$a*$b"|bc`\n"

echo -e "\e[1;33m #scale设定小数精度（数值范围）\e[0m"
echo "scale设置小数3位精度a/b:`echo "scale=3;$a/$b"|bc`"
echo "scale设置小数3位精度a*b:`echo "scale=10;$a*$b"|bc`"

示例4.字符串与数组处理

#!/bin/bash
string="alibaba is a great company"
echo "$string"
echo -e "获取字符串长度:${#string} \n"
echo -e "提取子字符串:${string:0:5} \n"
echo "查找子字符串alibaba:`expr index "$string" alibab`"

#数组案例
read -p "Please Input Data Array:" -a array_name
echo -e "\e[1;32mAll Array Arguments:${array_name[*]} \n"
# 取得数组元素的个数 length=${#array_name[*]}
echo -e "\e[1;36mArray Arguments Accounts:${#array_name[*]} \e[0m\n"
# 取得数组单个元素的长度
echo "array_name[1]:${array_name[1]}"
echo -e "\e[1;37mSingle Array Arguments(array_name[1]):${#array_name[1]} \e[0m\n"

0x01 语法记忆

示例1.分支与判断

#!/bin/bash
#if分支语句
read -p "Please INput A:" a
read -p "Please INput B:" b
read -p "Please INput C:" c	
#单分支语句(1)
if [ $a == $b ];then
  echo "a is equal to b!!" 
fi

if [ $a != $b ];then
  echo "a is not equal to b!!"
fi

#单分支语句(2)
if [ $c == $b ];then
  echo "c is equal to b!!"
else
  echo -e "c is not equal to b!!\n"
fi

#双分支语句
a=10
b=20
if [ $a == $b ]
then
   echo "a is equal to b"
elif [ $a -gt $b ];then
   echo "a is greater than b"
elif [ $a -lt $b ]
then
   echo "a is less than b"
else
   echo "None of the condition met"
fi

示例2.Case多分支语句

#!/bin/bash
#case 多分支语句
echo 'Input a number between 1 to 4'
echo  -e 'Your number is:\c'
read aNum
case $aNum in
        1)  echo -e 'You select 1\n'
        ;;
        2)  echo -e 'You select 2\n'
        ;;
        3)  echo -e 'You select 3\n'
        ;;
        4)  echo -e 'You select 4\n'
        ;;
        *)  echo -e 'You do not select a number between 1 to 4'
        ;;
esac

#新颖的思路可以利用这个来写小脚本
option="${1}"
case ${option} in
       -f) FILE="${2}"
          echo "File name is $FILE"
          ;;
       -d) DIR="${2}"
          echo "Dir name is $DIR"
          ;;
       *) 
          echo "`basename ${0}`:usage: [-f file] | [-d directory]"
          exit 1 # Command to come out of the program with status 1
          ;;
esac

示例3.For循环(Circulation)语句

#!/bin/bash
#For circulation Method 1
#一行一行得读取家目录总中.bash开头的文件
for FILE in $HOME/.bash*
do
  echo $FILE
done

#依次输出
for t in 1 2 3 4 5
do
  echo "输出第${t}个数字:$t"
done

#For Method2
sum=0
for((i=0;i<=100;i++))
do
    sum=$[ $sum + $i ]
done
echo "一到一百相加得:$sum"

#批量解压缩
ls *.tar.gz >> gz.log 2>/dev/null
ls *.tgz >> gz.log 2>/dev/null
echo "正在解压缩 : Wait,Please!!"
for i in $(cat gz.log)
    do
  tar -zxf $i &> /dev/null
    done
rm -rf gz.log

示例4.While 与 Until 语句：

#!/bin/bash
#while Circulation
num=0
sum=0
while [ $num -le 100 ]
do
  sum=$(($sum+$num))
  num=$[$num+1]
done
echo "1+2+....+100=$sum"

#Until Circulation
#输出 0 - 4
a=0 
until [ ! $a -lt 5 ]   #到5得时候就不成立了
do
  echo $a
  a=`expr $a + 1`
done
echo -e "\n"
#输出 0 - 5
b=0
until [ $b -gt 5 ]   # 可以等于5
do
  echo $b
  b=$(($b

示例5.函数嵌套与调用

#!/bin/bash

# Define your function here
Hello () {
echo -e "Hello Shell Program!!\n"
}

# Invoke your function
Hello

# Return Arguments！！
funWithReturn(){
    echo "The function is to get the sum of two numbers..."
    echo -n "Input first number: "
    read aNum
    echo -n "Input another number: "
    read anotherNum
    echo "The two numbers are $aNum and $anotherNum !"
    return $(($aNum+$anotherNum)) # 2
}
funWithReturn
# Capture value returnd by last command
ret=$?
echo "The sum of two numbers is $ret !"


#函数嵌套
# Calling one function from another
number_one () {
   echo "Url_1 is http://see.edu.cn/cpp/shell/"
   number_two
}
number_two () {
   echo "Url_2 is http://see.edu.cn/cpp/"
}

# unset -f number_two  #删除number_two函数
number_one

0x02 标准输入

示例1.命令行中输入参数，shell中使用位置参数变化

#!/bin/bash
#接受 输出得参数(Arguments),位置参数num1=$1
num2=$2
echo -e "输入得参数:"
echo $num1,$num2
let num3=$num1+$num2  #Add输入得参数
echo -e "num1+num2=\e[1;35m $num3 \e[0m"
##
echo -e "\n代表所有参数的个数:"
echo -e " A total of\e[1;32m $# \e[0m Parameters"   #所有参数的个数:
##
echo -e "\n整体参数:"
for i in "$*"
    do
        echo -e "ioutput:\e[1;31m $i \e[0m"   #整体参数
    done
##
echo -e "\n个体参数:"
for j in "$@"
    do
        echo -e "joutput:\e[1;36m $j \e[0m"   #个体参数
    done

示例2.标准输入和命令行输入验证

#!/bin/bash
# 实现标准输入格式验证的几种方法
read -p "Please two number:" NUM1 NUM2
function CheckNumberFormat(){
  local value=$1
  flag=$(echo $value | grep -E '[a-zA-Z_\.]'| wc -l)  #字符输入时候也的值得参考
  if [ $flag -eq 1 ];then
    echo "please input Number!"
    return 1
  else
    return 0
  fi
}

function CheckNumberLength(){
  local value=$1
  if [ ${#value} -lt 1 -o -z ${value} -o ! -n ${value} -o "${value}" == "" ];then
     echo "输入为空!"
  fi
}


function CheckNumber(){
  expr $1 + $2 + 0 > /dev/null
  if [ $? -ne 0 ];then
    echo "Input not number!"
  fi
}

示例3.匹配更改文件名称思路

#!/bin/bash
# 批量更改文件名称

#方式1:
for file in $(ls *.jpg);do	
  mv $file $(echo ${file} | sed 's#需要改变的文件名称#.jpg#g')
done

#方式2:
ls *.jpg | awk -F ' ' '{print " mv " $0,$1".jpg"}' | bash
ls *.jpg | awk -F ' ' '{cmd="mv "$0" "$1".jpg";system(cmd)}'
#补充示例：wiz笔记图片批量改名并且高亮显示
$ ls | awk -F '.' '{cmd="dd=$(date +%Y%m%d%H%M%S)$RANDOM;echo -e \"\033[1;31m" $1 "\033[0m $dd \"; mv " $0 " $dd."$2;system(cmd)}'


#方式3：
rename "需要更改的字符串" "改成什么" 对什么文件进行修改
rename "_finished.html" ".jpg" *.html

0x03 进制随机编码

示例1.进制转换采用bc

#!/bin/bash
#进制之间的转换 B->O->D->H
read -p "Please INput NUmeric:" abc
echo -e "\e[1;33;5m 进制转换结果 \e[0m"
echo "二进制(BIN):`echo "obase=2;$abc"|bc`"
echo "八进制(OCTAL):`echo "obase=8;$abc"|bc`"
echo "十进制(DEC):`echo "obase=10;$abc"|bc`"
echo "十六进制(HEX):`echo "obase=16;$abc"|bc`"

示例2.Ascii码与进制转换

#!/bin/bash
#Printf里的进制转换
exec 4<>test.txt  #绑定文件描述符号
while read line<&4
do
  echo -e "\e[1;37;5m 进制数据进行相互转换: \e[0m"
  printf "%-10s \n" Octal-Dec-hex:
  printf "%-10o" $line 
  printf "%-10d" $line
  printf "%-10x \n" $line
done

#Printf里的Ascll编码
##Octal -> ASCLL(123456789)
echo -e "\e[1;36m Octal-> Ascll\e[0m"
for i in 60 61 62 63 64 65 66 67 70 71
do
        printf "Octal=$i,Ascll=\\$i \n"
done

示例3.Shell脚本随机密码生成

#!/bin/bash
#(方式1) /dev/urandom文件是Linux内置的随机设备文件,内容有些太随机，包括很多特殊符号
#tr -dc '_A-Za-z0-9'  #将随机文件中其他的字符删除，仅保留大小写字母，数字，下划线
cat /dev/urandom | tr -dc '_a-zA-Z0-9' | head -c 12  #2hCOmV9AWAHA
</dev/urandom tr -dc '!@#$%^&*()-+=0-9a-zA-Z'| head -c14  #这样的方法值得学习
cat /dev/urandom | tr -dc '_a-zA-Z0-9!@#$%&*.' | fold -w 12 | head -1
cat /dev/urandom | tr -dc 'a-zA-Z0-9-_!@#$%^&*()_+{}|:<>?=' | fold -w 12| head -n 4 # 生成四组随机密码
.g0VvfzPooh*

#(方式2)利用上面的随机数来生成随机密码 
echo $RANDOM | md5sum | cut -c 1-8
60354ab3
#(方式2)生成随机密码(字串截取版本)设置变量key，存储密码的所有可能性(密码库)，如果还需要其他字符请自行添加其他密码字符
#使用$#统计密码库的长度
key="0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
num=${#key} 
pass=''  #设置初始密码为空
#循环8次，生成8为随机密码
for i in {1..8}
do
  index=$[RANDOM%num]   #无论怎么变都在key长度范围内
  pass=$pass${key:$index:1}  #拼接字符串
done
echo $pass


#(方式3)生成随机密码(UUID版本，16进制密码)
uuidgen | cut -c 1-8
a1cb0776
uuidgen | md5sum | cut -c 1-8
70101a14


#(方式4)当前进程号生成随机密码(进程ID版本,数字密码)-并不是一定随机一个shell的终端pid
echo $$ | md5sum | cut -c 1-8
93c6b48c


#(方式5)通过openssl产生随机数
openssl rand -base64 8
R1NSJ4rZGXQ=


#(方式6)通过date方式获取随机数
date +%s%S | md5sum | cut -c 1-8
# 259f7c4a

date +%s%S | sha1sum
date +%s%S | sha512sum | cut -c 1-8
# 03663f46

0x04 批量操作

示例1.批量创建用户以及采用随机密码

#!/usr/bin/env bash
# Step1.采用action函数的引用
[ -f /etc/init.d/functions ] && . /etc/init.d/functions
# Step2.判断是否是root
[ $UID -ne 0 ] && {
  echo -e "\e[1;31m [+] only allow root create user \e[0m"
  exit 1
}
# step3.创建主函数
function create(){
  for n in {1..3};do
    user=weiyi$n
    random=$(echo ${RANDOM}`date +%s%S`${user})                      
    pass="$(echo $random|md5sum|cut -f 2-9)"
    useradd $user &>/dev/null && echo $pass | passwd --stdin $user &>/dev/null
    RETVAL=$?
    if [ $RETVAL -eq 0 ];then
      action "useradd $user" /bin/true
    else
      action "useradd $user" /bin/false
    fi
    echo "$user  $pass" >> ./user.txt
  done
}

create

## 执行结果 ##
. add.sh
weiyi1-197e0f87
useradd weiyi1                                             [  OK  ]
weiyi2-65f0d13f
useradd weiyi2                                             [  OK  ]
weiyi3-7379dc89
useradd weiyi3                                             [  OK  ]

示例2.排除A文件中每一行在B文件中存在的字符串

for i in $(cat a.txt);do  
  flag=$(grep "${i}" b.txt -c);
  if [ $flag -eq 0 ];then 
    echo ${i} >> c.txt;
  fi;
done

0x05 文件读取

示例1.监测网站首页是否宕掉以及首页是否被修改
Step1.将需要监测的网站地址放入ip.txt中

cat > ip.txt <<END
192.168.100.197
192.168.100.198
192.168.100.199
192.168.100.200
192.168.100.201
192.168.100.202
END

Step2.写入一个监测函数思路就是利用网页的MD5指纹进行判断;

#!/usr/bin/env bash
function check(){
    cat ip.txt|while read line
    do
        url="http://${line}:$1/Login.do"
        urlmd5=$(curl -s -m 2 ${url} | md5sum | cut -f 1 -d " ")
        if [ "$urlmd5" == "6fc523910cb417d2247078125dd06782" ];then
            echo "$url OK"
        elif [ "$urlmd5" == "d41d8cd98f00b204e9800998ecf8427e" ];then
            echo "$url Connect Fail";
        else
            echo "$url content change";
        fi
    done
}
check 30082
check 40082

#执行结果
./check.sh
http://192.168.100.197:30082/Login.do OK
http://192.168.100.198:30082/Login.do Connect Fail

示例2.绑定输入与文件读取使用while语实现的三种方式

#!/bin/bash
## read input Variable
read -t 10 -p "Please Input [Accounts|Password]:" user pass
echo "输出的用户:$user"
echo "输入的密码:$pass"

## 方法1：While Read Line 绑定文件描述
echo -e "\e[1;32m 第一个文件输出\e[0m"
exec 3<>file.txt
while read line<&3
    do
      echo $line
    done

## 方法2：Cat FILE.TXT 读取文件中每一行
echo -e "\e[1;35m 第二个文件输出\e[0m"
cat file1.txt |\
  while read line
  do
    echo $line
  done


## 方法3
export number=0
while read line
do
  sed -i "3i\  pageid: ${number}" $line
  let number++
done < all.md

执行结果：

while read line 
do
echo " - ${line} - "
done < ip.txt
 - eth0      Link encap:Ethernet  HWaddr 02:42:ac:00:00:08 - 
 - inet addr:172.0.0.8  Bcast:172.0.255.255  Mask:255.255.0.0 - 
 - UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1 - 
 - RX packets:481 errors:0 dropped:0 overruns:0 frame:0 - 
 - TX packets:447 errors:0 dropped:0 overruns:0 carrier:0 - 
 - collisions:0 txqueuelen:0 - 
 - RX bytes:354214 (354.2 KB)  TX bytes:74829 (74.8 KB) - 
 -  - 
 - lo        Link encap:Local Loopback - 
 - inet addr:127.0.0.1  Mask:255.0.0.0 - 
 - UP LOOPBACK RUNNING  MTU:65536  Metric:1 - 
 - RX packets:56 errors:0 dropped:0 overruns:0 frame:0 - 
 - TX packets:56 errors:0 dropped:0 overruns:0 carrier:0 - 
 - collisions:0 txqueuelen:0 - 
 - RX bytes:5520 (5.5 KB)  TX bytes:5520 (5.5 KB) - 
 -

示例3.读取文件中的字符串，对里面的词组进行排序及出现

#!/bin/bash
eng="Making peace with what you don't have, that's what it's all about. I am a technical geek who is interested in learning computer technology."

#方式1：
echo $eng | sed -e 's#[ , . ]#\n#g' | sort | uniq -c | sort -nr #值得学习
# 2 what
# 1 you
# 1 with
# 1 who
# 1 that's
# 1 technology.
# 1 technical
# 1 peace
# 1 Making
# 1 learning


#方式2：
echo $eng | tr " " '\n' | sort | uniq -c | sort -nr


#（1）读取文件中内容，将词组中的各个字母进行排序，sed -r 使用正则匹配任意字符降序排列;
echo $eng | sed 's# ##g' | sed -r 's#(.)#\1\n#g' | sort |uniq -c | sort -rn -k1
# 13 t
# 12 e
# 12 a
# 8 n
# 8 i
# 8 h
# 7 o


#（2）采用方式2
echo $eng | grep -oE '[[:lower:]]' | sort | uniq -c | sort -rn
# 13 t
# 12 e
# 12 a
# 8 n
# 8 i
# 8 h
# 7 o

示例4.读取文件中的字符串，对里面的词组按照长度限定进行输出

#!/bin/bash
eng="Making peace with what you don't have, that's what it's all about. I am a technical geek who is interested in learning computer technology."
arr=($eng)

#方式1：
for value in $eng
do
  if [ ${#value} -gt 6 ];then
    echo ${#value}-${value}
  fi
done

#方法2：
for value in ${arr[*]}
do
  if [ ${#value} -gt 6 ];then
    echo ${#value}-${value}
  fi
done


#方法3：
echo $eng | tr ' ' '\n'| awk '{len=length($1); if(len > 6){print len"-"$1}}'


#执行的结果
9-technical
10-interested
8-learning
8-computer
11-technology.

0x06 执行效率

示例1.评定一个算法的效率打印所用时间

#!/bin/bash
start=$(date +%s)  #start=`date +%s`,等号不能有空格，如果有空格，会被变量当成命令
for(( i = 0; i < 5; i++ ));do
  echo $i >/dev/null
    sleep 1
done
end=`date +%s`
diff=$(($end-$start))  #执行时间之差
echo "use times(ms):"$diff
echo "use times(ms):"$(($end-$start))

0x07 安全运维

示例1.防止rm误删操作
解决方法：建立类似回收站机制

#1.建立回收站目录(此步骤可省略)
$ mkdir ~/.trash

#2.建立别名脚本
$ sudo vi /tmp/remove.sh
#!/bin/sh
#定义文件夹目录.trash
# home=$(env | grep ^HOME= | cut -c 6-)
trash="/.trash"
deltime=$(date +%Y%m%d-%H%M%S)
TRASH_DIR="${HOME}${trash}/${deltime}"
# 建立回收站目录当不存在的时候
if [ ! -e ${TRASH_DIR} ];then
   mkdir -p ${TRASH_DIR}
fi
for i in $*;do
  if [ "$i" = "-rf" ];then continue;fi
  #定义秒时间戳
  STAMP=`date +%s`
  #得到文件名称(非文件夹)，参考man basename
  fileName=`basename $i`
  #将输入的参数，对应文件mv至.trash目录，文件后缀，为当前的时间戳
  mv $i ${TRASH_DIR}/${fileName}.${STAMP}
done

sudo chmod +x /tmp/remove.sh

#3.建立别名机制
$sudo vi /etc/bashrc
# User specific aliases and functions
alias rm="sh /home/user/tool/remove.sh"

source /etc/bashrc

#4.每日03:00定时执行清空隐藏目录.trash当然您也可以清理前一天删除的
0 3 * * * find ~/.trash/ -mtime +1  -delete

0x08 防火墙应用

示例1.防止web的ddos攻击与反爬虫

#!/bin/bash
# 实现要求：
# 1.根据web日志或者网络连接数，监控某个IP并发连接数或者段时间内达到PV到100，即调用防火墙封掉对应IP；

function main(){
  cat access.log | awk '{print $1}' | sort | uniq -c | sort -r > a.log
  exec<a.log
  while read line
  do
    pv=$(echo $line|awk '{print $1}')
    ip=$(echo $line|awk '{print $2}')

    if [ $pv -gt $1 ] && [ $(iptables -L -n|grep "$ip"|wc -l) -eq 0];then
      itables -A INPUT -s $ip -j DROP 
    fi

  done
}

main 1024

0x09 字符串截取

描述: 在shell中截取字符串的常用方法，前面基础文章也将近过此处简单的做一个总结。

语法示例:

${#var}   # 字符串长度
${var#*/} # 获取尾部子字符串 *号在分隔符的前面，就去掉其之前的字符 (首个 / 后的值)
${var##*/} # (最尾 / 后的值)
${var%/*}  # 获取头部子字符串 *号在分隔符的前面，就去掉其之前的字符 (最尾 / 前的值)
${var%%/*} # (首个 / 前的值)
${var:start:len}  # 指定从左边第几个字符开始以及子串中字符的个数
${var:start}      # 从左边第几个字符开始一直到结束
${var:0-start:len} # 从右边第几个字符开始以及字符的个数
${var:0-start}     # 从右边第几个字符开始一直到结束
${var/dir/path}    # 表示将变量中第一个 dir 提换为 path
${var//dir/path}   # 表示将变量中全部 dir 提换为 path
${file-my.txt}  # 表示假如 $file 没设定，则使用 my.txt 作传回值。(空值及非空值时不作处理)
${file:-my.txt} # 表示假如 $file 没设定或为空值，则使用 my.txt 作传回值。 (非空值时不作处理)
${file+my.txt}  # 表示假如 $file 设为空值或非空值，均使用 my.txt 作传回值。(没设定时不作处理)
${file:+my.txt} # 表示假如 $file 为非空值，则使用 my.txt 作传回值。 (没设定及空值时不作处理)
${file=my.txt}  # 表示假如 $file 没设定，则使用 my.txt 作传回值，同时将 $file 赋值为 my.txt 。 (空值及非空值时不作处理)
${file:=my.txt} # 表示假如 $file 没设定或为空值，则使用 my.txt 作传回值，同时将 $file 赋值为 my.txt 。 (非空值时不作处理)
${file?my.txt}  # 表示假如 $file 没设定，则将 my.txt 输出至 STDERR。 (空值及非空值时不作处理)
${file:?my.txt} # 表示假如 $file 没设定或为空值，则将 my.txt 输出至 STDERR。 (非空值时不作处理)

总结说明:

#        删除最小的匹配前缀
##       删除最大的匹配前缀
%        删除最小的匹配后缀
%%     删除最大的匹配后缀

示例演示:

#!/bin/bash
# Description: Shell总字符串截取总结.
str="https://blog.weiyigeek.top/about/me"
# 原字符串输出
echo "string: [${str}]"
# 获得字符串的长度
length=${#str}; echo "length: [${length}]"
# 获得尾部字符串，分割符为'/'
substr=${str#*/};echo "substr: [${substr}]"
substr=${str##*/};echo "substr: [${substr}]"
# 获得头部字符串，分割符为'/'
headstr=${str%/*};echo "headstr: [${headstr}]"
headstr=${str%%/*};echo "headstr: [${headstr}]"
# 获得指定数量的字符串
numstr=${str:0:8};echo "numstr: [${numstr}]"
numstr=${str:8};echo "numstr: [${numstr}]"
numstr=${str:0-${length}:8};echo "numstr: [${numstr}]"
numstr=${str:0-8};echo "numstr: [${numstr}]"
# 指定字符替换字符串中字符
replstr=${str/https/ftp};echo "replstr: [${replstr}]"
replstr=${str/./-};echo "replstr: [${replstr}]"
replstr=${str//about/index};echo "replstr: [${replstr}]"
# 针对不同的变量状态赋值 (没设定、空值、非空值)
appid=${APP_ID:-NULL}; echo "appid: [${appid}]"     # 加有 : 没设定或为空值
appname=${APP_NAME:=null} ;echo "appname: [${appname}]"
appstderr=${APP_STDERR:?null};echo "appstderr: [${appstderr}]"
appadd=${APP_ADD:+null};echo "appadd: [${appadd}]"

执行结果:

./demo.sh
string: [https://blog.weiyigeek.top/about/me]
length: [35]
substr: [/blog.weiyigeek.top/about/me]
substr: [me]
headstr: [https://blog.weiyigeek.top/about]
headstr: [https:]
numstr: [https://]
numstr: [blog.weiyigeek.top/about/me]
numstr: [https://]
numstr: [about/me]
replstr: [ftp://blog.weiyigeek.top/about/me]
replstr: [https://blog-weiyigeek.top/about/me]
replstr: [https://blog.weiyigeek.top/index/me]
appid: [NULL]
appname: [null]
./demo.sh: line 26: APP_STDERR: null

0x0n 杂类脚本

示例1.Linux系统信息获取

#!/bin/bash
#zhushi:Linux 系统信息获取
#Author_Name=Weiyi
clear
if [ $# -eq 0 ];then    # "$#" 提取位置参数的个数
reset_terminal=$(tput sgr0)  #设置高亮输出
#Check OS Type (系统类型)
  os=$(uname -o)
  echo -e '\E[32m' "OS Type (系统类型):" $reset_terminal $os
#Check OS Release Version and Name (系统发行版本及名字)
  os_Rv=$(lsb_release -a | grep "Description" |awk '{print $2 " " $3 " " $4 " "$5$6 }')
  echo -e '\E[32m' "OS Release Version and Name (系统发行版本及名字):" $reset_terminal $os_Rv
#Check Architecture (系统Cpu 386 还是 X64架构)
  os_Ar=$(uname -m)
  echo -e '\E[32m' "Architecture (系统Cpu 386 还是 X64架构):" $reset_terminal $os_Ar
#Check Kernel Release (内核版本)
  os_Kr=$(uname -r)
  echo -e '\E[32m' "Kernel Release (内核版本)" $reset_terminal $os_Kr
#Check hostname
  os_hostname=$(echo $HOSTNAME)
  echo -e '\E[32m' "OS Hostname (主机名):" $reset_terminal $os_hostname
#Check Internal IP (内部IP)
  os_InIP=$(hostname -I)
  echo -e '\E[32m' "Internal IP (内部IP):" $reset_terminal $os_InIP
#Check External IP (外部IP)
  os_ExIP=$(curl -s http://ipecho.net/plain)
  echo -e '\E[32m' "External IP (外部IP):" $reset_terminal $os_ExIP
#Check DNS
  os_Dns=$(cat /etc/resolv.conf |grep -E "\<nameserver[ ]+" |awk '{print $NF}')
  # "\<nameserver[ ]+" 表示匹配以nameserver开头的多个[ ]+ //空格
  # "$NF" 默认以空格为分割符打印他得最后一行
  echo -e '\E[32m' "OS DNS (系统DNS):" $reset_terminal $os_Dns
#Check IF Connected To Internet or not (是否能连接英特网)
  ping -c 2 www.baidu.com &>/dev/null && echo "Internet:Connected(正常通信)" || echo "Internet:Disconnected(不能正常通信)" 
#Check logged In Users (当前登陆的用户)
  who >/tmp/who
  echo -e '\E[32m' "Logged In Users (当前登陆的用户)" $reset_terminal && cat /tmp/who
  rm -rf /tmp/who
#Check Proc Information
echo -e '\E[35m]' "########### Proc info (内存使用信息) ##############\n"
  system_mem_usages=$(awk '/MemTotal/{total=$2}/MemFree/{free=$2}END{print (total-free)/1024}' /proc/meminfo)
  echo -e '\E[32m' "System Mem Usages (当前系统使用内存信息-MB):" $reset_terminal $system_mem_usages
  application_mem_usages=$(awk '/MemTotal/{total=$2}/MemFree/{free=$2}/^Cached/{cached=$2}/Buffers/{buffers=$2}END{print (total-free-cached-buffers)/1024}' /proc/meminfo)
  echo -e '\E[32m' "Application Mem Usages (当前应用使用内存信息-MB):" $reset_terminal $application_mem_usages
#Check Cpu Information >> load average后面分别是1分钟、5分钟、15分钟的负载情况
echo -e '\E[35m]' "########### Cpu load info (Cpu负载信息) ##############\n"
  load_average=$(top -n 1 -b |grep "load average:" |awk '{print $10 $11 $12}')
  echo -e '\E[32m' "Cpu load info (Cpu负载信息):" $reset_terminal $load_average
#Check Disk Information
echo -e '\E[35m]' "########### Disk info (磁盘使用信息) ##############\n"
  disk_info=$(df -h |grep -vE "Filesystem|tmpfs" |awk '{printf $1 "\t" $5 "\n"}')
  # -p 使用输出更紧凑
  echo -e '\E[32m' "Disk Usages (磁盘使用信息):" $reset_terminal $disk_info
fi

示例2.进程监控

#!/bin/bash
#zhushi:httpd进程restart and if
test=$(ps aux | grep "httpd" | grep -v "grep") #截取Httpd进程,并把结果赋予变量test
if [ -n "$test" ];then
#if test 的值不为空，则执行then中的命令
    echo "$(date) httpd is ok!" >> /tmp/autostart-acc.log
    echo "httpd服务正常"
  else
    echo "http服务异常/正在重新启动httpd服务"
    /etc/rc.d/init.d/httpd restart &> /dev/null
    echo "$(date) restart httpd!!" >> /tmp/autostart-err.log
fi

示例3.apachelog日志分析

#!/bin/bash
#zhushi:Http status number
#author_Name:Weiyi

resettem=$(tput sgr0)
read -t 30 -p "Please,Input access Httpd log pash:" logfile

#Check http status Functions
Check_http_status(){
  http_status_codes=$(cat $logfile |grep -ioE 'HTTP\/1\.[0|1]\"[[:blank:]][0-9]{3}' |awk -F "[ ]+" '{
		if ( $2>100 && $2<200 )
			{i++} 
		else if ( $2>200 && $2<300 )
			{j++}
		else if ( $2>300 && $2<400 )
			{k++}
		else if ( $2>400 && $2<500 )
			{n++}
		else if ( $2>500 )
			{p++}
		}END{
			print i?i:0,j?j:0,k?k:0,n?n:0,p?p:0,i+j+k+n+p
		}')
  echo -e '\E[33m' "The Number of http status[100+]:" $resettem ${http_status_codes[0]}
  echo -e '\E[33m' "The Number of http status[200+]:" $resettem ${http_status_codes[1]}
  echo -e '\E[33m' "The Number of http status[300+]:" $resettem ${http_status_codes[2]}
  echo -e '\E[33m' "The Number of http status[400+]:" $resettem ${http_status_codes[3]}
  echo -e '\E[33m' "The Number of http status[500+]:" $resettem ${http_status_codes[4]}
  echo -e '\E[33m' "All Request numbers:" $resettem ${http_status_codes[5]}
}

#Check http Code 404/403 Functions
Check_http_code()
{
  http_code=$(cat $logfile |grep -ioE 'HTTP\/1\.[0|1]\"[[:blank:]][0-9]{3}' |awk -v total=0 -F '[ ]+' '{
		if ( $2 != "" )
			{code[$2]++;total++}
		else
			{exit}
	}END{
		print code[404]?code[404]:0,code[403]?code[403]:0,total
	}')
  echo -e '\E[33m' "The Number of http status[404]:" $resettem ${http_status_codes[0]}
  echo -e '\E[33m' "The Number of http status[403]:" $resettem ${http_status_codes[1]}
  echo -e '\E[33m' "All Request numbers:" $resettem ${http_status_codes[2]}
}

#调用函数
Check_http_status
echo -e '\n'
Check_http_code

示例4.Monitor脚本设置

#!/bin/bash
# tput sgr0 终端号关闭
resettem=$(tput sgr0)      

declare -A ssharray
i=0
number=""

for script_file in `ls -I "monitor_man.sh" ./`;do
    echo -e "\e[1;35m" "The script file:" ${i} '==>' ${resettem} ${script_file}
    grep "#zhushi:" ${script_file}     # 获取备注信息
    ssharray[$i]=${script_file}        # 将每个文件传人数组之中
    number="${number} | ${i}"          # 拼接子符
    i=$(( i+1 ))
done

while true
do	
  read -t 30 -p "Please input a number[ ${number} ]:" file    # 输出number变量
  if [[ ! ${file} =~ ^[0-9]+ ]];then
    exit 0
  fi
  /bin/sh ./${ssharray[$file]}    # 传入数组之中,并执行
done

实例5:日志访问数量统计

# 错误输入到err.txt
result=0
for i in {20..30};
do 
  count=$(grep -c "/cj/get.do?ksh=" localhost_access_log.2020-11-${i}.txt 2> err.txt)
  echo $count
  result=$(expr $result + $count) 
done
echo $result

示例5.字符串截取之文件拷贝

1	for i in $(cat 1.txt); do src=${i%-} ; target=${i#-}; srcname="${src%.}"; targetname="${target%/}";mkdir -p ${targetname}; find ${srcname}* -exec cp {} ${target} \; ; done

示例6.按照身份证进行字符串分隔创建目录

#!/bin/bash
# 
# $ find gz2020/photo -type f > ks.txt
for id in $(cat ks.txt); do 

# 判断路径以及身份证类别
if [[ ${#id} -ne 29 ]]; then
  echo ${id} >> exception.txt
else
  photo_name="${id##*/}"
  id_split="${id:7:2}/${id:9:4}/${id:13:4}"
  target_dir="/mnt/f/2020/pz_webchat/${id_split}"
  target_file="${target_dir}/${photo_name}"
  if [[ ! -e ${target_dir} ]]; then
    mkdir -p ${target_dir}
  fi

  # 区分后缀大小写
  ignore_case=$(echo "${target_file}" | grep -c "JPG")
  if [[ ${ignore_case} -eq 0 ]];then
    if [[ ! -e ${target_file} ]]; then
      cp -a ${id} ${target_file} || echo ${id} >> notcopy.txt
    else
      echo "normal - ${target_file}" >> exsit.txt
    fi
  else
    photo_name_case="${photo_name%.*}.jpg"
    target_file_case="${target_dir}/${photo_name_case}"
    if [[ ! -e ${target_file_case} ]]; then
      cp -a ${id} ${target_file_case} || echo ${id} >> notcopy.txt
    else
      echo "case - ${target_file} -> ${target_file_case}" >> exsit_case.txt
    fi
  fi
fi
done

示例7.Jenkins与K8s集群部署脚本实现部署、回退以及覆盖部署
脚本清单:

#!/bin/sh
export K8sMaster="${DEPLOY_USER}@${DEPLOY_HOST}"
export AppName="${APP_FILE##*/}"
export FindAppName=$(find ${WORKSPACE} -maxdepth 2 -type f -name ${AppName})

if [ "${FindAppName}" != "" ]; then
  echo "[-Msg]: ${FindAppName} ./${APP_NAME} Copying...."
  cp -rf ${FindAppName} ./${APP_NAME}
else
  echo "[-Error]: FindAppName param error!"
  exit 1
fi

function judge () {
  export ExistResult=$(ssh -p ${DEPLOY_PORT} ${K8sMaster} "ls ${APP_DIR} | grep ${RELEASE_VERSION} | wc -l")
}

function deploy () {
  if [[ ${ExistResult} -eq 0 || "${RELEASE_VERSION}" == "master" ]];then
    scp -P ${DEPLOY_PORT} "${APP_NAME}" ${K8sMaster}:${APP_DIR}${APP_NAME}
  else
    echo "[-Msg]: /${APP_NAME} current Deploy....."
  fi

  # 部署脚本
  if [[ "${RELEASE_VERSION}" == "master" ]];then
    ssh -p ${DEPLOY_PORT} ${K8sMaster} "kubectl -n ${K8S_NAMESPACE} delete pod -l ${K8S_SELECTOR}"
  else
    ssh -p ${DEPLOY_PORT} ${K8sMaster} "kubectl apply -f ${APP_DIR}${JOB_NAME}.yaml"
  fi
}

function rollback () {
  if [[ ${ExistResult} -ne 0 ]];then
    ssh -p ${DEPLOY_PORT} ${K8sMaster} "kubectl apply -f ${APP_DIR}${JOB_NAME}.yaml"
  else
    echo "[-Eroor]: /${APP_NAME} version not exsit....."
    exit 1
  fi
}

function redeploy () {
  # 如果是以前部署过则删除以前部署的项目目录,否则重新部署;
  if [[ "v${GIT_COMMIT}" = "v${GIT_PREVIOUS_SUCCESSFUL_COMMIT}" || ${ExistResult} -gt 0 ]];then
    echo -e "[-Message]:  ${RELEASE_VERSION} Version Exsit !"
    ssh -p ${DEPLOY_PORT} ${K8sMaster} "find ${APP_DIR} -d -maxdepth 1 -type f -name ${APP_NAME}"
    scp -P ${DEPLOY_PORT} "${APP_NAME}" ${K8sMaster}:${APP_DIR}${APP_NAME}
  fi

  # 重新部署
  deploy
}

# 判断是否存在历史版本
judge

case ${PREJECT_OPERATION} in
"deploy")
  echo "1.deploy"
  deploy
;;
"rollback")
  echo "2.rollback"
  rollback
;;
"redeploy")
  echo "3.redeploy"
  redeploy
;;
*)
  echo "[-Error] : params.PREJECT_OPERATION Param Error!"
  exit 1
;;
esac

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最后更新时间：2023-01-31 10:29:10
文章原始路径：_posts/系统运维/Linux/Shell编程/Shell脚本编程示例大全.md
转载注明出处，原文地址：https://blog.weiyigeek.top/2019/7-8-
本站文章内容遵循知识共享署名 - 非商业性 - 相同方式共享 4.0 国际协议

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