几个不错的Shell脚本

几个Shell脚本的例子，觉得还不错。

【例子:001】判断输入为数字，字符或其他

 #!/bin/bash
 read -p "Enter a number or string here:" input

 case $input in
    [0-9]) echo -e "Good job, Your input is a numberic! \n" ;;
 [a-zA-Z]) echo -e "Good job, Your input is a character! \n" ;;
        *) echo -e "Your input is wrong, input again!   \n"  ;;
 esac

【例子:002】求平均数

 #!/bin/bash

 # Calculate the average of a series of numbers.

 SCORE="0"
 AVERAGE="0"
 SUM="0"
 NUM="0"

 while true; do

   echo -n "Enter your score [0-100%] ('q' for quit): "; read SCORE;

   if (("$SCORE" < "0"))  || (("$SCORE" > "100")); then
     echo "Be serious.  Common, try again: "
   elif [ "$SCORE" == "q" ]; then
     echo "Average rating: $AVERAGE%."
     break
   else
     SUM=$[$SUM + $SCORE]
     NUM=$[$NUM + 1]
     AVERAGE=$[$SUM / $NUM]
   fi

 done

 echo "Exiting."

【例子:003 】自减输出

 [scriptname: doit.sh]
 while (( $# > 0 ))
 do
   echo $*
   shift
 done

 /> ./doit.sh a b c d e
 a b c d e
 b c d e
 c d e
 d e
 e

【例子:004 】在文件中添加前缀

 # 人名列表
 # cat namelist
 Jame
 Bob
 Tom
 Jerry
 Sherry
 Alice
 John

 # 脚本程序
 # cat namelist.sh
 #!/bin/bash
 for name in $(cat namelist)
 do
         echo "name= " $name
 done
 echo "The name is out of namelist file"

 # 输出结果
 # ./namelist.sh
 name=  Jame
 name=  Bob
 name=  Tom
 name=  Jerry
 name=  Sherry
 name=  Alice
 name=  John

【例子:005 】批量测试文件是否存在

 [root@host ~]# cat testfile.sh
 #!/bin/bash


 for file in test*.sh
 do
   if [ -f $file ];then
      echo "$file existed."
   fi
 done

 [root@host ~]# ./testfile.sh
 test.sh existed.
 test1.sh existed.
 test2.sh existed.
 test3.sh existed.
 test4.sh existed.
 test5.sh existed.
 test78.sh existed.
 test_dev_null.sh existed.
 testfile.sh existed.

【例子:005 】用指定大小文件填充硬盘

 [root@host ~]# df -ih /tmp
 Filesystem            Inodes   IUsed   IFree IUse% Mounted on
 /dev/mapper/vg00-lvol5
                        1000K    3.8K    997K    1% /tmp
 [root@host ~]# cat cover_disk.sh
 #!/bin/env bash
 counter=0
 max=3800
 remainder=0
 while true
 do
     ((counter=counter+1))
     if [ ${#counter} -gt $max ];then
         break
     fi
     ((remainder=counter%1000))
     if [ $remainder -eq 0 ];then
         echo -e "counter=$counter\tdate=" $(date)
     fi
     mkdir -p /tmp/temp
     cat < testfile > "/tmp/temp/myfile.$counter"
     if [ $? -ne 0 ];then
         echo "Failed to write file to Disk."
         exit 1
     fi
 done
 echo "Done!"
 [root@host ~]# ./cover_disk.sh
 counter=1000    date= Wed Sep 10 09:20:39 HKT 2014
 counter=2000    date= Wed Sep 10 09:20:48 HKT 2014
 counter=3000    date= Wed Sep 10 09:20:56 HKT 2014
 cat: write error: No space left on device
 Failed to write file to Disk.
 dd if=/dev/zero of=testfile bs=1M count=1

【例子:006 】通过遍历的方法读取配置文件

 [root@host ~]# cat hosts.allow
 127.0.0.1
 127.0.0.2
 127.0.0.3
 127.0.0.4
 127.0.0.5
 127.0.0.6
 127.0.0.7
 127.0.0.8
 127.0.0.9
 [root@host ~]# cat readlines.sh
 #!/bin/env bash
 i=0
 while read LINE;do
     hosts_allow[$i]=$LINE
     ((i++))
 done < hosts.allow
 for ((i=1;i<=${#hosts_allow[@]};i++)); do
     echo ${hosts_allow[$i]}
 done
 echo "Done"
 [root@host ~]# ./readlines.sh
 127.0.0.2
 127.0.0.3
 127.0.0.4
 127.0.0.5
 127.0.0.6
 127.0.0.7
 127.0.0.8
 127.0.0.9
 Done

【例子:007 】简单正则表达式应用

 [root@host ~]# cat regex.sh
 #!/bin/env sh
 #Filename: regex.sh
 regex="[A-Za-z0-9]{6}"
 if [[ $1 =~ $regex ]]
 then
   num=$1
   echo $num
 else
   echo "Invalid entry"
   exit 1
 fi
 [root@host ~]# ./regex.sh 123abc
 123abc

 #!/bin/env bash
 #Filename: validint.sh
 validint(){
     ret=`echo $1 | awk '{start = match($1,/^-?[0-9]+$/);if (start == 0) print "1";else print "0"}'`
     return $ret
 }

 validint $1

 if [ $? -ne 0 ]; then
     echo "Wrong Entry"
     exit 1
 else
     echo "OK! Input number is:" $1
 fi

【例子:008】简单的按日期备份文件

 #!/bin/bash

 NOW=$(date +"%m-%d-%Y")      # 当前日期
 FILE="backup.$NOW.tar.gz"    # 备份文件
 echo "Backing up data to /tmp/backup.$NOW.tar.gz file, please wait..."  #打印信息
 tar xcvf /tmp/backup.$NOW.tar.gz /home/ /etc/ /var       # 同时备份多个文件到指定的tar压缩文件中
 echo "Done..."

【例子:009】交互式环境select的使用

 #!/bin/bash

 echo "What is your favorite OS?"

 select OS in "Windows" "Linux/Unix" "Mac OS" "Other"
 do
     break
 done

 echo "You have selected $OS"

 root@localhost:~/training# ./select.sh
 What is your favorite OS?
 1) Windows
 2) Linux/Unix
 3) Mac OS
 4) Other
 #? 1
 You have selected Windows

【例子:010 】批量修改文件名的脚本

 #!/bin/bash
 # we have less than 3 arguments. Print the help text:
 if [ $# -lt 3 ]; then
         cat <<-EOF
         ren -- renames a number of files using sed regular expressions
         USAGE: ren.sh 'regexp' 'replacement' files
         EXAMPLE: rename all *.HTM files in *.html:
         ren 'HTM$' 'html' *.HTM
         EOF
         exit 0
 fi
 OLD="$1"
 NEW="$2"
 # The shift command removes one argument from the list of
 # command line arguments.
 shift
 shift
 # $* contains now all the files:
 for file in $*
 do
 if [ -f "$file" ]; then
      newfile=`echo "$file" | sed  "s/${OLD}/${NEW}/g"`
          if [ -f "$newfile" ]; then
              echo "ERROR: $newfile exists already"
          else
              echo "renaming $file to $newfile "
              mv "$file" "$newfile"
          fi
 fi
 done
 root@localhost:~/training# ./ren.sh "HTML$" "html" file*.HTML
 renaming file10.HTML to file10.html
 renaming file1.HTML to file1.html
 renaming file2.HTML to file2.html
 renaming file3.HTML to file3.html
 renaming file4.HTML to file4.html
 renaming file5.HTML to file5.html
 renaming file6.HTML to file6.html
 renaming file7.HTML to file7.html
 renaming file8.HTML to file8.html
 renaming file9.HTML to file9.html

【例子:011 】break语句在脚本中的应用示例

 #!/bin/bash

 for VAR1 in 1 2 3
 do
     for VAR2 in 0 5
     do
         if [ $VAR1 -eq 2 -a $VAR2 -eq 0 ]
         then
             break 2  # 退出第二重循环，亦即退出整个循环
         else
             echo "第一个变量:$VAR1 第二个变量:$VAR2"
         fi
     done
 done
 root@localhost:~/training# ./test.sh
 第一个变量:1 第二个变量:0
 第一个变量:1 第二个变量:5

【例子:012】/dev/tty在读取人工输入中的特殊作用

 #!/bin/bash
 # 用来验证两次输入的密码是否一致

 printf "Enter your passwd: "            # 提示输入
 stty -echo                              # 关闭自动打印输入字符的功能
 read pwd1 < /dev/tty                    # 读取密码
 printf "\nEnter again: "                # 再次提示输入
 read pwd2 < /dev/tty                    # 再读取一次以确认
 stty echo                               # 打开自动打印输入字符的功能

 if [[ "$pwd1" == "$pwd2" ]]; then       # 对两次输入的密码进行判断
     echo -e "\nPASSWORD: the same"
 else
     echo -e "\nPASSWORD: not same"
 fi
 root@localhost:~/training# ./test.sh
 Enter your passwd:
 Enter again:
 PASSWORD: the same

【例子:013】/dev/null在脚本中的简单示例

 #!/bin/bash

 if grep /bin/bash  $0 > /dev/null 2>&1    # 只关心命令的退出状态而不管其输出
 then                                      # 对退出状态进行判断
     echo -e "/bin/bash in $0\n"
 else
     echo -e "/bin/bash not in $0\n"
 fi
 脚本输出:
 root@localhost:~/training# ./test.sh
 /bin/bash in ./test.sh

【例子:014】构建自己的bin目录存放执行脚本，然后随便执行的简单示例

 $ cd                     # 进入家目录
 $ mkdir bin              # 创建$HOME目录下自己的bin目录
 $ mv test.sh bin         # 将我们自己的脚本放到创建的bin目录下
 $ PATH=$PATH:$HOME/bin   # 将个人的bin目录放到PATH中

 $ test.sh                # 现在就可以直接执行自己的脚本了

【例子:015】将长句子中单词长度为5及以上的单词打印出来

 #!/bin/bash
 # filename: test.sh

 sentence="When you're attracted to someone it just means that your subconscious is attracted to their subconscious, subconsciously.
 So what we think of as fate, is just two neuroses knowing they're a perfect match."

 for word in ${sentence}
 do
     new=`echo $word | tr -cd '[a-zA-Z]'`  # 去除句子中的 ，或者'
     len=${#new}                           # 求长度
     if [ "$len" -ge 5 ]                   # 再判断
     then
         echo $new
     fi
 done
 root@localhost:~# ./test.sh
 youre
 attracted
 someone
 means
 subconscious
 attracted
 their
 subconscious
 subconsciously
 think
 neuroses
 knowing
 theyre
 perfect
 match

【例子:016】根据输入的数据(年4位，月2位)，来判断上个月天数

 #!/bin/bash

 get_last_day()
 {
     year=`expr substr $1 1 4`
     month=`expr substr $1 5 2`
     curr_month=`echo $month | tr -d '0'`   # 去掉里面的0，方便后面计算
     echo "curr_month=$curr_month"
     last_month=`expr $curr_month - 1`
     case $last_month in
         01|03|05|07|08|10|12|0)
             echo "上个月天数-->" 31   ;;
         02)
             if [ `expr $year % 400` = 0 ] ; then
                 echo "上个月天数-->" 29
             elif [ `expr $year % 4` = 0 ] && [ `expr $year % 100` != 0 ] ; then
                 echo "上个月天数-->" 29
             else
                 echo "上个月天数-->" 28
             fi                       ;;
          *)
             echo "上个月天数-->" 30
     esac
 }

 if [ $# -ne 1 ]; then
     echo "Usage: $0 201608"
 else
    get_last_day $1
 fi

 root@localhost:~/training# ./test.sh 201601
 上个月天数--> 31

【例子:017】统计文件中每个单词出现的频率

 #!/bin/sh
 # 从标准输入读取文件流，再输出出现频率的前n，默认:25个单词的列表
 # 附上出现频率的计数，按照这个计数由大到小排列
 # 输出到标准输出
 # 语法: wf [n]

 tr -cs A-Za-z\' '\n' |
   tr A-Z a-z |
     sort |
       uniq -c |
         sort -k1,1nr -k2 |
           sed ${1:-25}q
 root@localhost:~/training# wf 10 < /etc/hosts | pr -c4 -t -w80
       6 ip                1                   1 archive           1 capable
       3 ff                1 allnodes          1 are               1 cn
       2 localhost         1 allrouters

【例子:018 】使用while和break等待用户登录

 #!/bin/bash
 # 等待特定用户登录，每30秒确认一次
 # filename: wait_for_user_login.sh

 read -p "Ener username:-> " user
 while true
 do
     if who | grep "$user" > /dev/null
     then
         echo "The $user now logged in."
         break
     else
         sleep 30
     fi
 done
 root@localhost:~/shell# ./wait_for_user_login.sh
 Ener username:-> guest
 The guest now logged in.

【例子:019 】结合while,case,break,shift做简单的选项处理

 #!/bin/bash

 # 将标志变量设置为空值
 file=  verbose=  quiet=  long=

 while [ $# -gt 0 ]                    # 执行循环直到没有参数为止
 do
         case $1 in                    # 检查第一个参数
         -f)     file=$2
                 shift ;;              # 移位-f，使得结尾shift得到$2的值
         -v)     verbose=true
                 quiet= ;;
         -q)     quiet=true
                 verbose= ;;
         -l)     long=true ;;
         --)     shift
                 break ;;
         -*)     echo "$0: $1: unrecongnized option >&2" ;;
         *)      break ;;
         esac
 done
 ~

【例子:020 】read读取多个变量处理，及文本遍历的两种常用方式

 #!/bin/bash

 while IFS=: read user pwd pid gid fullname homedir shell         # IFS作为列之间的分隔符号，read读取多个变量
 do
     printf "The user=%s homedir=%s\n" "$user" "$homedir"         # 对文本中的行进行处理
 done < /etc/passwd                                               # 读取文件

 # 第二种方式
 #!/bin/bash

 cat /etc/passwd |
     while IFS=: read user pwd pid gid fullname homedir shell
 do
     printf "The user=%s homedir=%s\n" "$user" "$homedir"
 done

【例子:021 】复制目录树的两个简单脚本

 #!/bin/bash
 # 方式一
 find /root/shell -type d -print     |   # 寻找所有目录
   sed 's;/root/shell/;/tmp/shell/;' |   # 更改名称，使用;作为定界符
     sed 's/^/mkdir -p /'            |   # 插入mkdir -p 命令
       sh -x                             # 以Shell的跟踪模式执行

 # 方式二
 find /root/shell -type d -print     |   # 寻找所有目录
   sed 's;/root/shell/;/tmp/shell/;' |   # 更改名称，使用;作为定界符
     while read newdir                   # 读取新的目录名
     do
         mkdir -p $newdir
     done
 ~

【例子:022】发邮件给系统前10名磁盘用户，要求清理磁盘空间

 #!/bin/bash

 cd /home                       # 移动到目录的顶端
 du -s *       |                # 产生原始磁盘用量
   sort -nr    |                # 以数字排序，最高的在第一位
     sed 10q   |                # 在前10行之后就停止
       while read amount name   # 将读取的数据分别作为amount, name变量
       do
           mail -s "disk usage warning" $name << EOF
 Gretings. You are one of the top 10 consumers of disk space
 on the system. Your home directory users $amount disk blocks.

 Please clean up unneeded files, as soon as possible.

 Thanks,
 Your friendly neighborhood system administrator.
 EOF
       done

【例子:023 】将密码文件转换为Shell邮寄列表

 #!/bin/bash

 # passwd-to-mailing-list
 #
 # 产生使用特定shell的所有用户邮寄列表
 #
 # 语法: passwd-to-mailing-list < /etc/passwd

 # 删除临时性文件
 rm -rf /tmp/*.mailing-list

 # 从标准输入中读取
 while IFS=: read user passwd uid gid name home Shell
 do
     Shell=${Shell:-/bin/sh}           # 如为空shell,指/bin/sh
     file="/tmp/$(echo $Shell | sed -e 's;^/;;' -e 's;/;-;g').mailing-list"
     echo $user, >> $file
 done
 root@localhost:~# vim passwd-to-mailing-list
 root@localhost:~# passwd-to-mailing-list < /etc/passwd
 root@localhost:~# cat /tmp/bin-bash.mailing-list
 root,
 test,
 user,
 root@localhost:~# cat /tmp/bin-sh.mailing-list
 libuuid,
 jerry,

【例子:024】变更目录时更新PS1

 #!/bin/bash

 cd()
 {
     command cd "$@"       # 实际改变目录
     x=$(pwd)              # 取得当前目录的名称,传递给变量
     PS1="${x##*/}\$ "     # 截断前面的组成部分，指定给PS1
 }
 root$                     # 最后输出，类似于这种，看不到目录的完整路径

【例子:025】根据XML文件中的license时间来判断是否过期

   中国,福建,福州市,鼓楼区
   123123
   hdsas_base_3.0.0.2_16Q2_RC2
   _RC257971fe611f0
   f04c3d1eb4bf6113
   2016-08-02 16:46:39
   30 days



 获得2016-08-02 16:46:39时间加上30 days
 期限，得到时间减去系统当前时间，小于7天，显示license即将在几天后过期。

代码如下:

 #!/bin/bash

 CURR_TIME=$(date +'%Y%m%d')
 FILE_TIME=$(grep 'issuetime' hdlicense.xml | tr -d '[\-a-z<>/]' | awk '{print $1}')
 REAL_TIME=$(date -d "$FILE_TIME +30 days" +%Y%m%d)

 d1=$(date "+%s" -d "$REAL_TIME")
 d2=$(date "+%s" -d "$CURR_TIME")

 EXPI_TIME=$(((d1-d2)/86400))

 if [ "$EXPI_TIME" -lt "7" ]; then
     echo "你的license将在 $EXPI_TIME 天后过期!"
 fi

【例子:026】根据参数来判断是否要新创建目录

 #!/bin/bash

 DIR=$1

 if [ X"$DIR" = X"" ]; then
     echo "Usage: `basename $0` directory to create" >&2
     exit 1
 fi

 if [ -d $DIR ];then
     echo "The directory you create is exist."
     exit 0
 else
     echo "The $DIR does not exist, will create now."
     echo -n "Create it now? [y/n]"
     read ANS
     if [ X"$ANS" = X"y" -o X"$ANS" = X"Y" ];then
         mkdir $DIR > /dev/null 2>&1
         if [ $? !=0 ]; then
                 echo "Error creating the direcory $DIR" >&2
                 exit 1
         else
                 echo "Create $DIR OK"
                 exit 0
         fi
     fi
 fi

【例子:027】创建新目录，并将当前目录下的所有.txt文件拷贝到新目录中

 #!/bin/bash

 DIR=testdir
 THERE=`pwd`

 mkdir $DIR > /dev/null 2>&1

 if [ -d $DIR ]; then
     cd $DIR
     if [ $? = 0 ]; then
         HERE=`pwd`
         cp $THERE/*.txt $HERE
     else
         echo "Cannot cd to $DIR"
         exit 1
     fi
 else
     echo "Cannot create directory $THERE"
     exit 1
 fi

【例子:028】菜单显示小脚本

 #!/bin/bash

 USER=`whoami`
 HOST=`hostname -s`
 DATE=`date '+%d/%m/%Y'`

 help(){
 cat <
 -----------------------------------------------------
 User: $USER          Host: $HOST         Date: $DATE
 -----------------------------------------------------
                 1. List files in current directory
                 2. Use the vi editor
                 3. See who is on the system
                 H. Help screen
                 Q. Exit Menu
 -----------------------------------------------------
         Your Choice [1, 2, 3, 4, H, Q] >
 EOF
 }

 while :
 do
         help
         echo -n "Enter your choice: "
         read ANS
         case $ANS in
                 1) ls -lart ;;
                 2) vi       ;;
                 3) who      ;;
                 H) help     ;;
                 Q) exit 0   ;;
         esac
 done

【例子:029 】判断输入是否为纯字母示例

 #!/bin/bash
 error_info()
 {
         echo "$@ error, please check your input."
         exit 1
 }

 check_name()
 {
         NAME=`echo $1 | tr -d '[a-zA-Z]'`
         if [ X"$NAME" = X"" ];then
                 return 0
         else
                 return 1
         fi
 }

 while :
 do
         echo -n "Please Input your first name:"
         read F_NAME
         if check_name $F_NAME; then
                 echo "Your First Name met the condition."
                 break
         else
                 echo "Wrong input, please enter again."
         fi
 done


 while :
 do
         echo -n "Please Input your last name:"
         read L_NAME
         if check_name $L_NAME; then
                 echo "Your Last Name met the condition."
                 break
         else
                 error_info
         fi
 done
 ~