find files

find

soft link

Packing and Compression

Software Installation

apt-get

1. Find files

The find command is powerful and is usually used to search for qualified files in a specific directory

serial number	Order	effect
01	find[path] -name "*.py"	Find files with the extension .py in the specified path , including subdirectories

If the path is omitted, it means to search under the current folder

The wildcards learned before are also available when using the find command

exercise goal

Search for files in the desktop path whose filename contains 1

find -name "*1*"

Search for all files with .txt extension in the desktop directory

find -name "*.txt"

Search for files starting with the number 1 in the desktop directory

find -name "1*"

2. Soft link

serial number	Order	effect
01	ln -s linked source file link file	Create soft links to files , similar to shortcuts under Windows

Notice:

A hard link file is created without the -s option

The two files occupy the same size of hard disk space, and hard links to files are hardly established during work

The source file should use an absolute path instead of a relative path, so that it can still be used normally after moving the linked file

exercise goal

Move 01.py in the desktop directory to demo/b/c

Create a soft link FirstPython of 01.py in the desktop directory

Use relative path and absolute path respectively to establish soft link of FirstPython

Move FirstPython to the demo directory, and compare the difference between using relative paths and absolute paths

Introduction to Hard Links

When using ln to create a link, if there is no -s option, a hard link will be created instead of a soft link

Hard Link Walkthrough

Create a hard link 01_hard of ~/desktop/demo/b/c/01.py in the ~/desktop/demo directory

Use ls-l to view the number of hard links of files (hard links - how many ways to access files or directories)

Delete ~/desktop/demo/b/c/01.py and use tree to confirm the three link files in the demo directory

Schematic diagram of soft and hard links of files

In Linux , the file name and the data of the file are stored separately

hint:

In Linux , only the hard link number of the file == 0 will be deleted

Use ls -l to view the number of hard links in a file

In daily work, hard links to files are hardly established , just know

3. Package compression

Packing and compression is a way of backing up files in daily work

In different operating systems, the commonly used packaging and compression methods are different

Windows commonly used rar

Mac commonly used zip

Linux commonly used tar.gz

3.1 Packing/unpacking

tar is the most commonly used backup tool in Linux . This command can pack a series of files into a large file , and can also restore a series of files from a packaged large file.

tar is only responsible for packaging, not for compression

The command format of tar is as follows:

# 打包文件
tar -cvf 打包文件.tar 被打包文件/路径...

# 解包文件
tar -xvf 打包文件.tar

Description of tar options

options	meaning
c	Generate archive file, create package file
x	unpack the archive
v	List the detailed process of archiving and unarchiving, and display the progress
f	Specify the name of the archive file, f must be followed by a .tar file , so it must be placed at the end of the option

Packing and Unpacking Walkthrough

Delete everything under the desktop

Create three blank files 01.py, 02.py, 03.py under the desktop

Pack these three files into a py.tar package

Create a new tar directory and move py.tar to the tar directory

unpack py.tar

3.2 Compression/Decompression

3.2.1 gzip

The combination of tar and gzip commands can realize file packaging and compression

tar只负责打包文件，但不压缩

用gzip压缩tar打包后的文件，其扩展名一般用xxx.tar.gz

在Linux中，最常见的压缩文件格式就是xxx.tar.gz

在tar命令中有一个选项-z可以调用gzip，从而可以方便实现压缩和解压缩功能

命令格式如下：

# 压缩文件
tar -zcvf 打包文件.tar.gz 被压缩的文件/路径...

# 解压缩文件
tar -zxvf 打包文件.tar.gz

# 解压缩到指定路径
tar -zxvf 打包文件.tar.gz -C 目标路径

选项	含义
-C	解压缩到指定目录，注意：要解压缩的目录必须存在

3.2.2 bzip2(two)

tar与bzip2命令结合可以使用实现文件打包和压缩（用法和gzip一样）

tar只负责打包文件，但不压缩

用bzip2压缩tar打包后的文件，其扩展名一般用xxx.tar.bz2

在tar命令中有一个选项-j可以调用bzip2,从而可以方便的实现压缩和解压缩功能

命令格式如下

# 压缩文件
tar -jcvf 打包文件.tar.bz2 被压缩的文件/路径...

# 解压缩文件
tar -jxvf 打包文件.tar.bz2

4.软件安装

4.1通过apt安装/卸载软件

apt是Advanced Packaging Tool 是Linux下的一款安装包管理工具

可以在终端方便的安装/卸载/更新安装包

# 安装软件
$ sudo apt install 软件包

# 卸载软件
$ sudo apt remove 软件名

# 更新已安装的包
$ sudo apt upgrade

安装演练

# 一个小火车提示
$ sudo apt install sl

# 一个比较漂亮的查看当前进程排名的软件，退出程序用q
$ sudo apt install htop

4.2配置软件源

如果希望在ubuntu中安装软件，更加快速，可以通过设置镜像源，选择一个访问网速更快的服务器来提供软件下载/安装服务

提示：更换服务器后，需要一个相对比较长时间的更新过程，需要耐心等待。更新完成后，再安装软件都会从新设置的服务器下载软件了

所谓镜像源，就是所有服务器的内容是相同的（镜像），但是根据所在位置的不同，国内服务器通常速度会更快一些

点击按钮，显示应用程序

点击红色方框内容处

如果有比较倾向的服务器，找到对应的选中即可，如果不知道哪个服务器效果比较好，点击选择最佳服务器按钮

寻找最佳服务器的过程，时间较长，耐心等待

测试完成后，点击选择服务器按钮

然后按照提示输入对应用户的密码，点击授权

点击关闭，在弹窗中，点击重新载入，将所有软件源的信息进行更新缓存，耗时较长，耐心等待

内容总结于:https://space.bilibili.com/37974444

Linux-Find files, soft links, package compression and software installation