Linux experiment six shell programming (loop)

Linux experiment six shell programming (loop)

1. Use shell to write multiplication table program

vi chengfabiao.sh

Then press the lowercase i key to edit

#!/bin/bash
for ((i=1;i<10;++i))
do
        for ((j=1;j<=i;j++))
        do
        		#-n是不自动换行，-e激活双引号内的转义字符
                echo -ne "$i*$j=$((i*j))\t" 
        done
        echo #这个echo是为了换行使用
done

After editing, press esc to exit the editing mode, then press: wq to save and exit.
Use chmod 755 chengfabiao.sh to give the file executable permissions
sh chengfabiao.sh to execute the file

2. Write a script program that can take different actions according to the input command line parameters: if it is a directory, list the files in the directory; if it is an executable file, use a shell to execute it; if it is a readable file, then Display its content in split screen.

vi panduan.sh

#!/bin/bash
if [ -e $1 ]
then
        if [ -d $1 ]
        then
                ls $1
        elif [ -x $1 ]
        then
                sh $1
        elif [ -r $1 ]
        then
                more $1
        fi
else
        echo "输入的参数无效！"
fi

Use the q key to exit split-screen viewing mode

3. Write a shell script to create the directory /userdate, create 100 directories in batches under this directory, namely user1~user100, and set the permissions of each directory. Among them, the permissions of other users are: read; the permissions of the file owner are : Read, write, execute; the group permissions of the file owner are: read, write.

vi mulu,.sh

#!/bin/bash
mkdir /userdate
cd /userdate
for ((i=1;i<=100;i++))
do
	mkdir user$i
	chmod 764 user$i
done