几个shell小程序 --鸟哥的linux私房菜

1. 读入一个文件夹，察看其下所有文件的属性
read -p "enter the dir:" dir
filelist=`ls $dir`                   #`` 而非‘’
for filename  in $filelist
do
        perm=""           # 每次都重置为空
        test -r "$dir/$filename" && perm="$perm readable"
        test -w "$dir/$filename" && perm="$perm writable"
        test -x "$dir/$filename" && perm="$prem excuted"
        echo "$dir/$filename   has the permssions of $perm"
done

2. 输入的如果是yes就继续，如果是no，就停止
read -p "input y/n: " yn
if [ "$yn" == "Y" -o "$yn" == "y" ]; then   #此处的-o用法 和“$y”而不能是$y,且if之后有，
        echo "ok,continue"
        elif [ "yn" == "N" -o "$yn" == "n" ];then  
        echo "oh,interrupt"
        else
                echo "i don't know what your choice"
fi


3.通过端口检测使用的协议
#detect the www ,ftp ssh
echo "the www ,ftp ,ssh will be detect"
testing=`netstat -tunl|cut -d ":" -f 1|cut -d " " -f 1` #此处的netstat -tnul 还有后面的cut的格式
if [ "$testing" == "80" ];then
        echo "www is running on your sysytem"
        elif [ "$tesing" == "21" ];then
        echo "ftp is ruuning on your sysytem"
        elif [ "$tesing" == "22" ];then
        echo "ssh is running on your system"
        else
                echo "none of the www ftp ssh is running on your system"
                fi
4.看看/etc/passwd里面的用户在第几行
#output the users of passwd
accountlist=`cat /etc/passwd|cut -d ":" -f 1`
line=1
for account in $accountlist
do
    echo "the $line  is $account"
    line=$(($line + 1))
done

5. 写一个文件，文件名是你输入的名字加日期

echo -e "i will use touch make a file "

read -p  "please input a fileuser" fileuser

filename=${fileuser:-"filename"}

date1=`date --date='2 days ago' +%F`

date2=`date --date='1 days ago' +%F`

date3=`date +%Y%m%d`

file1="$filename""$date1"

file2="$filename""$date2"

file3="$filename""$date3"

touch $file1

touch $file2

touch $file3

6.数值的加法 

echo -e "you can input two numbers,i will compute them"

read -p "the first  number" num1

read -p "the second  number" num2

total=$(($num1+$num2))                                      #here the + could be replaced by */ %*

echo "the total number of $num1 and $num2 is $total "

 

7.查看文件的存在性，是否是目录及文件的权限

#!bin/bash

#program 

#     let user input a filename ,the program will searchfilename

#   1.exit ? 2.file/directory ? 3 file permissions

#history

#2/24/2012        Vbird  first release

PATH=/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

export PATH

#1.input a filename

read -p "please input a filename:  " filename

test ! -e  $filename && echo "filename doesn't exit" && exit 0

#2.test the filetype

test -f  $filename && filetype="regular file"

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

#3.test the permissions

test -r  $filenam &&  perm="readable" 

test -w  $filenam &&  perm="$perm writable"

test -x  $filenam &&  perm="$perm excutalbe"

#4.output the result

echo "the $filename is a $filetype "

echo "the $filename has the $perm of permissions"

8.test yes or no 和上面的一个比价类似

#test yes or no

read -p "input yes or no: " 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"