课后练习
1、编写脚本/root/bin/systeminfo.sh,显示当前主机系统信息，包括主机名，IPv4地址，操作系统版本，内核版本，CPU型号，内存大小，硬盘大小。
#!/bin/bash
echo Hostname: `hostname`
echo IP address: `ifconfig|egrep -o "[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}"|head -n1`
echo System version: `cat /etc/system-release`
echo kernel version: `uname -r`
echo CPU type : `lscpu |grep ‘Model name‘|sed ‘s/.*://‘|sed ‘s/^[[:space:]]\+//‘`
echo Disk size :`fdisk -l|grep "sda:"|sed ‘s/.*://‘|sed ‘s/,.*//‘|sed ‘s/^[[:space:]]\+//‘`
echo Memory size : `free -m|grep "Mem"|tr -s [[:space:]]|cut -d" " -f2` MB
运行结果
[[email protected] ~]# bash systeminfo.sh Hostname: shao IP address: 10.1.53.2 System version: CentOS Linux release 7.2.1511 (Core) kernel version: 3.10.0-327.el7.x86_64 CPU type : Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz Disk size :214.7 GB Memory size : 1824 MB
2、编写脚本/root/bin/backup.sh，可实现每日将/etc/目录备份到/root/etcYYYY-mm-dd中
#!/bin/bash cp -arv /etc /root/etc`date +%F`
3、编写脚本/root/bin/disk.sh,显示当前硬盘分区中空间利用率最大的值
#!/bin/bash echo "The max using rate is:`df |grep "/dev/sd"| cut -c 44-46 | sort -nr | head -1`%"
运行结果
[[email protected] ~]# bash disk.sh The max using rate is: 74%
4、编写脚本/root/bin/links.sh,显示正连接本主机的每个远程主机的IPv4地址和连接数，并按连接数从大到小排序
#!/bin/bash echo "the links number is:" netstat -nt |tr -s ‘ ‘ |cut -d ‘ ‘ -f5 |cut -d: -f1 |grep [0-9]|sort |uniq -c|sort -nr
运行结果
[[email protected] ~]# bash links.sh the links number is: 2 10.1.53.3
5、写一个脚本/root/bin/sumid.sh，计算/etc/passwd文件中的第10个用户和第20用户的ID之和
#!/bin/bash echo ‘The sum is‘ id1=`cat /etc/passwd | sed -n ‘10p‘ | cut -d: -f3` id2=`cat /etc/passwd | sed -n ‘20p‘ | cut -d: -f3` let idsum=$id1+$id2 echo "The sum is:$idsum" unset idsum
运行结果
[[email protected] bin]# bash sumid.sh The sum is:70
6、写一个脚本/root/bin/sumspace.sh，传递两个文件路径作为参数给脚本，计算这两个文件中所有空白行之和
#!/bin/bash file1_blank=`grep "^[[:space:]]*$" $1 | wc -l` file2_blank=`grep "^[[:space:]]*$" $2 | wc -l` sumspace=$[$file1_blank+$file2_blank] echo "The tatal blank line:$sumspace"
运行结果
[[email protected] ~]# bash sumspace.sh /etc/passwd /etc/fstab The tatal blank line:1
7、写一个脚本/root/bin/sumfile.sh,统计/etc, /var, /usr目录中共有多少个一级子目录和文件
#!/bin/bash etcnum=`ls -d /etc/*|wc -l` varnum=`ls -d /var/*|wc -l` usrnum=`ls -d /usr/*|wc -l` echo "the totalfile is $[etcnum+varnum+usrnum]"
运行结果
[[email protected] bin]# bash sumfile.sh the totalfile is 298
8、写一个脚本/root/bin/argsnum.sh，接受一个文件路径作为参数；如果参数个数小于1，则提示用户“至少应该给一个参数”，并立即退出；如果参数个数不小于1，则显示第一个参数所指向的文件中的空白行数
#!/bin/bash read -p "Enter a filename:" file [ -z "$file" ] && echo "please enter a file name" && exit 2 echo -n "The blank line number is:" echo `grep -c ‘^[[:space:]]*$‘ $file`
运行结果
[[email protected] ~]# bash sumspace.sh Enter a filename: please enter a file name [[email protected] ~]# bash sumspace.sh Enter a filename:/etc/fstab The blank line number is:1
9、写一个脚本/root/bin/hostping.sh，接受一个主机的IPv4地址做为参数，测试是否可连通。如果能ping通，则提示用户“该IP地址可访问”；如果不可ping通，则提示用户“该IP地址不可访问”
#!/bin/bash [ $# -ne 1 ] && echo "please input one ipaddr" && exit 2 ping -c1 -w1 $1 &> /dev/null && echo "ping successful" || echo "ping failed"
运行结果
[[email protected] bin]# bash hostping.sh please input one ipaddr [[email protected] bin]# bash hostping.sh 10.1.254.254 ping successful
10、判断硬盘的每个分区空间和inode的利用率是否大于80，如果是，发邮件通知root磁盘满
#!/bin/bash mount=$((df;df -i) | grep "/dev/sd" | tr -s ‘ ‘ | cut -d‘ ‘ -f5 | grep -o "[[:digit:]]\+" | sort | tail -1) [ "$mount" -ge 80 ] && echo "disk almost full" | mail -s "dangerous" root || exit 3
11、指定文件做为参数，判断文件是否为.sh后缀，如果是，添加x权限
#!/bin/bash read -p "please input a test file: " FILENAME [ ! -e $FILENAME -o ! -f $FILENAME ] && echo "please input a real file" && exit 100 echo $FILENAME | grep -q ‘.*\.sh$‘ && (chmod +x $FILENAME ; echo "Add x right for the file successfully") || echo "this is not a .sh file"
运行结果
[[email protected] bin]# ls excute.sh hostping.sh per.sh sumfile.sh [[email protected] bin]# bash excute.sh please input a test file: hostping.sh Add x right for the file successfully
12、判断输入的IP是否为合法IP
#!/bin/bash
read -p "please input one useful ip:" ip_addr
echo $ip_addr | grep -E "^(\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>.){3}\<([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\>$" &> /dev/null && echo "this is a useful ip" || echo "this is not a useful ip"
运行结果
[[email protected] bin]# bash checkip.sh please input one useful ip:10.1.534.1 this is not a useful ip [[email protected] bin]# bash checkip.sh please input one useful ip:10.1.53.1 this is a useful ip
13、计算1+2+3+...+100
#!/bin/bash
#!/bin/bash
echo -e "\033[34m1-100 all positive integer‘s sum\033[0m : `echo {1..100} | tr " " "+" | bc`"
运行结果
[[email protected] bin]# bash 100sum.sh 1-100 all positive integer‘s sum : 5050
方法二：seq -s + 1 100 | bc
14、输入起始值A和最后值B，计算从A+（A+1）...+(B-1)+B的总和
#!/bin/bash read -p "first number:" a read -p "second number:" b [ $a -ge $b ] && echo "sum is `seq -s+ $b $a | bc`" || echo "sum is `seq -s+ $a $b | bc`"
运行结果
[[email protected] bin]# bash sumAB.sh first number:4 second number:8 sum is 30 [[email protected] bin]# bash sumAB.sh first number:100 second number:1 sum is 5050
15、chmod -rw /tmp/file1，编写脚本/root/bin/per.sh,判断当前用户对/tmp/file1文件 是否不可读且不可写
#!/bin/bash [ -r /tmp/file1 -o -w /tmp/file1 ] && echo "`whoami` can read or write /tmp/file1" || echo "`whoami` can not read and can not write /tmp/file1"
运行结果
[[email protected] bin]# bash per.sh root can read or write /tmp/file1
16、编写脚本/root/bin/nologin.sh和login.sh,实现禁止和充许普通用户登录系统。
禁止
#!/bin/bash [ -e /etc/nologin ] && echo "the normal user can not login already" ; exit || touch /etc/nologin echo "disable normal user login "
允许
#!/bin/bash [ -e /etc/nologin ] && rm -f /etc/nologin echo "enable user login "
17、写一个脚本/root/bin/createuser.sh，实现如下功能： 使用一个用户名做为参数，如果指定参数的用户存在，就显 示其存在，否则添加之；显示添加的用户的id号等信息
#!/bin/bash read -p "please input you name:" name if cat /etc/passwd | cut -d: -f1 | grep -q "^$name$";then echo "the username already exits" else useradd $name cat /etc/passwd | grep "^$name\b" fi
运行结果
[[email protected] bin]# bash createuser.sh please input you name:shao the username already exits [[email protected] bin]# bash createuser.sh please input you name:liu liu:x:1014:1019::/home/liu:/bin/bash
18、写一个脚本/root/bin/yesorno.sh，提示用户输入yes或 no,并判断用户输入的是yes还是no,或是其它信息
#!/bin/bash [ $# -ne 1 ] && echo "please input an arg" && exit ans=`echo $1 | tr ‘A-Z‘ ‘a-z‘` if [ $ans = yes -o $ans = y ] then echo "yes" elif [ $ans = n -o $ans = no ] then echo "no" else echo "error" fi
运行结果
[[email protected] bin]# bash yesorno.sh y yes [[email protected] bin]# bash yesorno.sh please input an arg [[email protected] bin]# bash yesorno.sh No no [[email protected] bin]# bash yesorno.sh YES yes
19、写一个脚本/root/bin/filetype.sh,判断用户输入文件路 径，显示其文件类型（普通，目录，链接，其它文件类型）
#!/bin/bash read -p "please input a filename:" filename ! [ -e $filename ] && echo "The filename do not exist" && exit if [ -h $filename ] ;then echo "filetype is syslink file" elif [ -d $filename ] ;then echo "filetype is dirction" elif [ -f $filename ] ;then echo "filetype is common file" else echo "filetype is other" fi
运行结果
[[email protected] bin]# bash filetype.sh please input a filename:/etc filetype is dirction [[email protected] bin]# bash filetype.sh please input a filename:/etc/redhhat-release The filename do not exist [[email protected] bin]# bash filetype.sh please input a filename:/etc/redhat-release filetype is syslink file [[email protected] bin]# bash filetype.sh please input a filename:/etc/issue filetype is common file
20、写一个脚本/root/bin/checkint.sh,判断用户输入的参数是否为正整数
#!/bin/bash [ $# -ne 1 ] && echo "Please input a number" && exit if [[ $1 =~ ^0*[1-9][0-9]*$ ]] then echo "int" else echo "not int" fi
运行结果
[[email protected] bin]# bash checkint.sh Please input a number [[email protected] bin]# bash checkint.sh 0 not int [[email protected] bin]# bash checkint.sh 12 int [[email protected] bin]# bash checkint.sh 1.1 not int
时间： 2024-10-08 06:15:00