Linux [directory command]

Introduction

This will be a memo for learning.

A directory is a folder. A folder that stores files. The directories are nested.

The role of the main directory

/bin

• Stores command executables used by both general and administrative users
• In particular, stores the executable files of the most important commands required for Linux operation.

/dev

• Stores device files (files that allow hardware to be handled as files)

/etc

• Store configuration file

• The configuration file of the application that runs on Linux and the file related to the configuration of Linux itself are placed. /home

• Home directory (personal directory assigned to each Linux user) is placed

• Users are free to create files and directories in their home directory

/sbin

• Stores command executables for admin users

/tmp

• Store temporary files
• Used to temporarily save the result as a file while the application is running

/usr

• Stores various applications and their accompanying files

/var

• Store changing data
• Stores logs created to run the application

1.cd(change directory）

cd [directory]

Command to move directory

Specifying a special directory

There is a special way to specify the current directory, parent directory, and home directory.

2.pwd

pwd [option]　　　#ほとんどoptionをつけることはない

Command to display the current directory (current directory) A command that tells you where you are now

3.ls

ls [option][Directory file name]　

Command to display a list of files and directories Find out which folders/files are in your current directory

Convenient path name expansion

You can specify multiple files at once using pathname expansion

Path name expansion

Concrete example
#Display a list of files with the extension html
$ls *.html
index.html home.html job.html

#Show files starting with z and ending with 4 characters
$ls /bin/z???
/bin/zcat /bin/zcmp /bin/znew

Frequently used options

ls -l View detailed information about the file

ls -a Show all files, including hidden files

ls -F Show file type

4.mkdir(make directory)

mkdir [option]<Directory name to create>

Command to create a directory

Frequently used options

-p Create deep directories at once With the -p option, you don't have to create a directory called test, 2019 in advance.

$mkdir -p test/2019/08

5.rmdir(remove directory)

rmdir <Directory name>

Command to delete an empty directory (an error will occur if you try to delete a non-empty directory) I rarely use it (mostly I use the rm command)

6. Path

The path is the address information of a directory or file. Represent the directory hierarchy delimiter with "/"

Pass type

1) Absolute path

The absolute path is the path starting from the root directory ("/").

/home/kume/code/README.md

2) Relative path

Relative path is the path starting from the current directory.

code/README.md

7. Column (Check how to use commands)

1) help command

Display help messages for commands with the --help option

<command> --help

#Concrete example
　ls --help
Usage: ls[option]...[File]...

It will give you an overview of how to use the command, a list of available options, and use it when you want to understand the outline of the command.

2) man command

Display the command manual with the man command It's more detailed than the --help option, so use it when you want to understand the command properly.

man <Command name you want to look up>

#Concrete example
man ls
NAME
    ls -list directory contents
#You can search by keyword
man -k move