linux shell

#判断文件类型以及文件的权限
#!/bin/sh
echo "This script will show you filetype and permission"

read -p "Please input a file name:" filename
test -z "$filename" && echo "Please input somthing !!!" && exit 0
test ! -e "$filename" && echo "the file $filename DO NOT exist!!!" && exit 0

test -f "$filename" && filetype="is a regular file"
test -d "$filename" && filetype="is a dictory"
test -p "$filename" && filetype="is a PIPE file"
test -b "$filename" && filetype="is a block device"
test -c "$filename" && filetype="is a character device"
test -S "$filename" && filetype="is a socket file"
test -L "$filename" && filetype="is a link file"


test -r "$filename" && per="$per readable "
test -w "$filename" && per="$per writable "
test -x "$filename" && per="$per executable "
test -u "$filename" && per="$per set UID"
test -g "$filename" && per="$per set GID "
test -k "$filename" && per="$per sticky bit "

#使用中括号等同于上面的书写格式[-k "$filename"] && per="$per sticky bit "

echo "the file $filename you have input $filetype, and permission is $per"

　　 #编写脚本的格式
　　 #/bin/bash #声明文件使用哪个shell
    #program
    #this program is used to XCXXX
    #history
    #DATE Author version
    PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
    export PATH
    #脚本内容
    read -p "please input your name:" username
    read -p "please input your sex:" sex
    echo "yourname and sex are: $username $sex"

Y/y N/n 判断

#!/bin/sh
read -p "Please input (y/Y n/N) : " yn
#if 的[左空格 内容 右空格] 一定要有空格 -o 参数是或的意思 可以使用[  ]||[  ]的形式
if [ "$yn"='y' -o "$yn" = 'Y' ];then
        echo "ok go on please"
        exit 0
fi

if [ "$yn" = 'n' -o "$yn" = 'N' ];then
        echo "bey bey"
        exit 0
fi

echo "Sorry, I don't know your choice ! $yn"

case

#!/bin/sh
#$1 默认参数 $0 脚本名称
case $1 in
        "one")
                echo "the paramter is one"
                ;;
        "")
                echo "you should input something!"
                ;;
        *)
                echo "you only can input one "
                ;;
esac

执行脚本

sh -x XXX.sh  x 显示sh脚本中执行到的代码段

sh -v XXX.sh v 显示sh脚本中的代码

sh -n XXX.sh 检查sh有没有语法错误

while

#!/bin/bash
#Program: when you input y/Y, then stop while
#History:2017/10/10 Author wlc version first release
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
while [ "$yn" != "y" ]
do
        read -p "Please input y/Y to stop while: " yn
done

until

#!/bin/bash
#Program: when you input y/Y, then stop while
#History:2017/10/10 Author wlc version first release
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
until [ "$yn" = "y" -o "$yn" = "Y" ]
do
        read -p "Please input y/Y to stop while: " yn
done

for

s = 0
for ((i=0;i<=100;i++))
do
        s=$(($s+$i))
done

echo "1+2+3+...+100=$s"