shell script练习

执行脚本的几种方式：

1. sh a.sh 或者  bash a.sh  调用的是 /bin/bash 进程执行的，所以脚本不需要执行权限。

2. 直接使用绝对路径执行， /home/script/a.sh  ，脚本需要有执行权限，如果没有权限可执行 chmod a+x a.sh 加入执行权限。

    (lampp启动数据库用的就是： /opt/lampp/lampp startmysql )

sh03.sh 根据时间创建目录

#!/bin/bash
echo -e "I will use 'touch' command to create 3 files."
read -p "Please input your filename:" fileuser

filename=${fileuser:-"filename"}

echo $filename

date1=$(date -d '-2 day' +%Y%m%d) #前两天的日期
date2=$(date -d '-1 day' +%Y%m%d) #前一天的日期
date3=$(date "+%Y%m%d")           #下面三行在配置文件名
file1=${filename}${date1}
file2=${filename}${date2}
file3=${filename}${date3}

touch "$file1"
touch "$file2"
touch "$file3"

sh04.sh 数字运算

#!/bin/bash
echo -e "You SHOULD input 2 numbers,I will cross them!
"
read -p "first number: " firstnu
read -p "second number: " secnu
total=$(($firstnu*$secnu))
echo -e "
 The result of $firstnu x $secnu is ==> $total"

sh05.sh 使用 test 判断文件存在和权限

echo -e "Please input a filename,I will check the filename's type and permission. 

"
read -p "Input a filename : " filename
test -z $filename && echo "You MUST input a filename." && exit 0

test ! -e $filename && echo "The filename '$filename' DO NOT exist" && exit 0

test -f $filename && filetype="regulare file"
test -d $filename && filetype="directory"

test -r $filename && perm="readable"
test -w $filename && perm="$perm writable"
test -x $filename && perm="$perm executable"

echo "The filename:$filename is a $filetype"
echo "And the permissions are : $perm"

sh06.sh 使用 [] 中括号做判断

read -p "Please input (Y/N):" yn
[ "$yn" == "Y" -o "$yn" == "y" ] && echo "OK,continue" && exit 0
[ "$yn" == "N" -o "$yn" == "n" ] && echo "Oh,interrupt!" && exit 0
echo "I don't know what your choice is" && exit 0

sh07.sh 脚本传参

echo "The script name is ==> $0"
echo "Total parameter number is ==> $#"
[ "$#" -lt 2 ] && echo "The number of parameter is less than 2. Stop here."  && exit 0
echo "Your whole parameter is ==> '$@'"
echo "The 1st parameter ==> $1"
echo "The 2nd parameter ==> $2"

sh08.sh shift去除参数

echo "Total parameter number is ==> $#"
echo "Your whole parameter is ==> '$@'"

shift  # 进行第一次 "一个变量的 shift "

echo "Total parameter number is ==> $#"
echo "Your whole parameter is ==> '$@'"

shift 3 # 进行第二次 "三个变量的 shift "
echo "Total parameter number is ==> $#"
echo "Your whole parameter is ==> '$@'"

sh06-2.sh if...then 单层判断

read -p "Please input (Y/N):" yn

if [ "$yn" == "Y" ] || [ "$yn" == "y" ]; then
  echo "OK,continue"
  exit 0
fi

if [ "$yn" == "N" ] || [ "$yn" == "n" ]; then
  echo "Oh,interrupt!"
  exit 0
fi

echo "I don't know what your choice is" && exit 0

sh06-3.sh  if...elif...else...fi 

read -p "Please input (Y/N):" yn

if [ "$yn" == "Y" ] || [ "$yn" == "y" ]; then
  echo "OK,continue"
  exit 0
elif [ "$yn" == "N" ] || [ "$yn" == "n" ]; then
  echo "Oh,interrupt!"
  exit 0
else
  echo "I don't know what your choice is" && exit 0
fi

sh09.sh

if [ "$1" == "hello" ]; then
  echo "Hello,how ary you?"
elif [ "$1" == "" ]; then
  echo "You MUST input parameters,ex> {$0 someword}"
else
  echo "The only parameter is 'hello',ex> {$0 hello}"
fi

sh10.sh

echo "Now,I will detect your Linux server's services!"
echo -e "The www, ftp, ssh, and mail will be detect! 
"

testing=$(netstat -tuln | grep ":80 ")
if [ "$testing" != "" ]; then
  echo "WWW is running in your system."
fi
testing=$(netstat -tuln | grep ":22 ")
if [ "$testing" != "" ]; then
  echo "SSH is running in your system."
fi
testing=$(netstat -tuln | grep ":21 ")
if [ "$testing" != "" ]; then
  echo "FTP is running in your system."
fi
testing=$(netstat -tuln | grep ":25 ")
if [ "$testing" != "" ]; then
  echo "Mail is running in your system."
fi

sh11.sh case...esac 判断

case $1 in
  "hello") 
 echo "Hello,how are you?"
  ;;
"")
  echo "You MUST input parameters,ex> {$0 someword}"
  ;;
*)
  echo "The only parameter is 'hello',ex> {$0 hello}"
  ;;
esac

sh12.sh  

echo "This program will print your selection !"
read -p "Input your choice: " choice
case $choice in
#case $1 in
 "one")
    echo "Your choice is ONE"
  ;;
 "two")
  echo "Your choice is TWO"
  ;;
 "three")
  echo "Your choice is THREE"
  ;;
*)
  echo "Usage $0 {one|two|three}"
  ;;
esac

sh12-2.sh 使用function

function printit(){
echo -n "Your choice is " #加上 -n 可以不断行继续在同一行显示
}

echo "This program will print your selection !"
case $1 in
"one")
printit; echo $1 | tr 'a-z' 'A-Z' #将参数做大小写转换!
;;
"two")
printit; echo $1 | tr 'a-z' 'A-Z'
;;
"three")
printit; echo $1 | tr 'a-z' 'A-Z'
;;
*)
echo "Usage $0 {one|two|three}"
;;
esac

sh12-3.sh function带参数

function printit(){
  echo -n "Your choice is $1" #加上 -n 可以不断行继续在同一行显示
}

echo "This program will print your selection !"
case $1 in
  "one")
        printit 1;
        ;;
  "two")
        printit 2;
        ;;
  "three")
        printit 3; 
        ;;
   *)
        echo "Usage $0 {one|two|three}"
        ;;
esac

sh13.sh while do done循环

  read -p "Please input yes/YES to stop this program:" yn
while [ "$yn" != "yes" -a "$yn" != "YES" ]
do
  read -p "Please input yes/YES to stop this program:" yn
done

echo "OK! you input the correct answer."

 sh13-2.sh  until  do  done循环

until [ "$yn" == "yes" -o "$yn" == "YES" ]
do
  read -p "Please input yes/YES to stop this program:" yn
done
echo "OK! you input the correct answer."

sh14.sh

s=0
i=0
while [ "$i" != "100" ]
do
  i=$(($i+1))  #每次 i 都会增加1
  s=$(($s+$i)) #每次都会累加一次！
done
echo "The result of '1+2+3+...+100' is ==> $s"

sh15.sh  for...do...done循环

for animal in dog cat elephant
do
  echo "There are ${animal}s..."
done

sh16.sh 

users=$(cut -d ':' -f1 /etc/passwd) #获取账号名称
for username in $users #开始循环进行
do
  id $username
  finger $username
done

sh17.sh  (该shell script需要检查，还有问题)

network="192.168.66" #先定义一个域的前面部分
for sitenu in $(seq 1 255)  #seq为sequence(连续)的缩写之意
do
  #下面的语句取得ping 的回传值是正确的还是失败的
  ping -c 1 -w ${network}.${sitenu} &> /dev/null && result=0 || result=1
  #开始显示结果是正确的启动(UP) 还是错误的没有连通(DOWN)
  if [ "$result" == 0 ]; then
     echo "Server ${network}.${sitenu} is UP."
  else
     echo "Server ${network}.${sitenu} is DOWN."
  fi
done

检查网段IP使用情况

#!/bin/bash
#main---
network=192.168.1
ping_count=3
IP=1
:>IP_use
:>IP_idle
:>ping_action
echo "`date "+%Y%m%d %H:%M:%S"`----->脚本开始执行......"
while [ $IP -lt 255 ]
do
host=$network.$IP
echo "-------->开始检测$host服务器通迅是否正常,ping次数$ping_count."
ping $host -c $ping_count  >.ping_tmp
sleep 1
cat .ping_tmp  >>ping_action
echo "-------->服务器$host检测已完成."
sum_ping=`tail -2 .ping_tmp |head -1 |awk -F, '{print$2}' |cut -c 2-2`
loss_ping=`tail -2 .ping_tmp |head -1 |awk -F, '{print$4}'|cut -c 2-5`
if [ $sum_ping -eq $ping_count ];then
    echo "-->$host  IP 已经在使用中"
    echo "-->$host  IP 已经在使用中"  >>IP_use
  else
    echo "$host IP 目前空闲:$loss_ping"
    echo "$host IP 目前空闲"  >>IP_idle
fi
IP=$((IP+1))
done
echo "`date "+%Y%m%d %H:%M:%S"`----->脚本运行完毕......"

sh18.sh  遍历目录下文件的权限

#1.先看看这个目录是否存在啊？
read -p "Please input a directory:" dir
if [ "$dir" == "" -o ! -d "$dir" ]; then
   echo "The $dir is NOT exist in your system."
   exit 1
fi

#2.开始测试文件。
filelist=$(ls $dir) #列出所有在该目录下的文件名
for filename in $filelist
do
  perm=""
  test -r "$dir/$filename" && perm="$perm readable"
  test -w "$dir/$filename" && perm="$perm writable"
  test -x "$dir/$filename" && perm="$perm executable"
  echo "The file $dir/$filename's permission is $perm"
done

sh19.sh for...do...done 循环

read -p "Please input a number,I will count for 1+2+...+your_input:" nu
s=0
for((i=1;i<=$nu;i=i+1))
do
  s=$(($s+$i))
done
echo "The result of '1+2+3+...+$nu' is ==> $s"