Linux简单的shell脚本实例

╰半夏微凉° 2023-06-15 11:20 6阅读 0赞

一些简单的shell实例，不积硅步，无以至千里，不积小流，无以成江河！

1.模拟linux登录shell

#!/bin/bash
    echo -n "login:" 
    read name
    echo -n "password:"
    read passwd
    if [ $name = "syp" -a $passwd = "syp" ];then
    echo "the host and password is right!"
    else echo "input is error!"
    fi

2.比较两个数大小

#!/bin/bash
    echo "please enter two number"
    read a
    read b
    if test $a -eq $b
    then echo "NO.1 = NO.2"
    elif test $a -gt $b
    then echo "NO.1 > NO.2"
    else echo "NO.1 < NO.2" 
    fi

3.查找/root/目录下是否存在该文件

#!/bin/bash
    echo "enter a file name:"
    read a
    if test  -e /root/$a 
    then echo "the file is exist!"
    else echo "the file is not exist!"
    fi

4.for循环的使用

#!/bin/bash
    clear
    for num in 1 2 3 4 5 6 7 8 9 10
    do
        echo "$num"
    done

5..查看是否当前用户

#!/bin/bash
    echo "Please enter a user:"
    read a
    b=$(whoami)
    if test $a = $b
    then echo "the user is running."
    else echo "the user is not running."
    fi

6.删除当前目录下大小为0的文件

#!/bin/bash
    for filename in `ls`
    do
        if test -d $filename
        then b=0
        else    
           a=$(ls -l $filename | awk '{ print $5 }')
                if test $a -eq 0
                 then rm $filename
                 fi
            fi      
    done

7.如果/export/um\_lpp\_source下有文件，那么将其文件系统大小改为3G

#!/bin/bash
    while line=`ls /export/um_lpp_source`
    do
        if test $line=""
        then  echo "NULL"
        sleep 1
        else echo $line
        chfs -a size=3G /export/um_lpp_source
        exit 0
        fi
    done

8.测试IP地址

#!/bin/bash
    for i in  1 2 3 4 5 6 7 8 9 
    do
        echo "the number of $i computer is "
        ping -c 1 192.168.0.$i
    done

9.如果test.log的大小大于0，那么将/opt目录下的\*.tar.gz文件拷贝到当前目录下

#!/bin/sh
    a=2
    while name="test.log"
    do
       sleep 1
       b=$(ls -l $name | awk '{print $5}')
       if test $b -gt $a
       then `cp /opt/*.tar.gz .`
       exit 0
       fi
    done

10.打印读取的内容，为下面的例子做准备

#!/bin/bash
    while read name
    do
    echo $name
    done

11.从0.sh中读取内容并打印

#!/bin/bash
    while read line
    do
        echo $line
    done < 0.sh

12.读取a.c中的内容并做加1运算

#!/bin/bash
    test -e a.c
    while read line
    do
      a=$(($line+1))
    done < a.c
    echo $a

13.普通无参数函数

#!/bin/bash
    p ()
    {
        echo "hello"
    }
    p

14.给函数传递参数

#!/bin/bash
    p_num ()
    {
        num=$1
        echo $num
    }
    for n in $@
    do
        p_num $n
    done

15.创建文件夹

#!/bin/bash
    while :
    do
        echo "please input file's name:"
        read a
        if test -e /root/$a
        then
             echo "the file is existing Please input new file name:"
        else
            mkdir $a
            echo "you aye sussesful!"
            break 
        fi
    done

16.获取本机IP地址

#!/bin/bash
    ifconfig | grep "inet addr:" | awk '{ print $2 }'| sed 's/addr://g'

17.查找最大文件

#!/bin/bash
    a=0
    for  name in *.*
    do
        b=$(ls -l $name | awk '{print $5}')
        if test $b -gt $a
        then a=$b
        namemax=$name
        fi
    done
    echo "the max file is $namemax"

18.查找当前网段内IP用户，重定向到ip.txt文件中

#!/bin/bash
    a=1
    while :
    do
        a=$(($a+1))
        if test $a -gt 255
        then break
        else
            echo $(ping -c 1 192.168.0.$a | grep "ttl" | awk '{print $4}'| sed 's/://g')
            ip=$(ping -c 1 192.168.0.$a | grep "ttl" | awk '{print $4}'| sed 's/://g')
            echo $ip >> ip.txt
        fi
    done

19.打印当前用户

#!/bin/bash
    echo "Current User is :"
    echo $(ps | grep "$$" | awk '{print $2}')

20.case语句练习

#!/bin/bash
    clear
    echo "enter a number from 1 to 5:"
    read num
    case $num in
        1) echo "you enter 1"
        ;;
        2) echo "you enter 2"
        ;;
        3) echo "you enter 3"
        ;;
        4) echo "you enter 4"
        ;;
        5) echo "you enter 5"
        ;;
        *) echo "error"
        ;;
    esac

21.yes/no返回不同的结构

#!/bin/bash
    clear
    echo "enter [y/n]:"
    read a
    case $a in
        y|Y|Yes|YES) echo "you enter $a"
        ;;
        n|N|NO|no) echo "you enter $a"
        ;;
        *) echo "error"
        ;;
    esac

22.内置命令的使用

#!/bin/bash
    clear
    echo "Hello, $USER"
    echo "Today 's date id `date`"
    echo "the user is :"
    who
    echo "this is `uname -s`"
    echo "that's all folks! "

23.打印无密码用户

#!/bin/bash
    echo "No Password User are :"
    echo $(cat /etc/shadow | grep "!!" | awk 'BEGIN { FS=":" }{print $1}')