Linux Command Line Basics

System Directory Structure

Case sensitive
Root path: /

Path	Detail
/bin	executable commands(for all users)
/sbin	super bin (for root)
/boot	startup, kernel
/dev	devices (files)
/etc	config files, pure text files
/home	user home dirctory
/root	root user home
/lib	library files
/opt	large software
/proc	process
/sys	hardware info
/tmp	temporary
/usr	user application
/var	variable, e.g log
/media	media
/mnt	mount

$ > newfile / >> new file
$ touch newfile
$ cat > file

$ rm -rf *

Modify access time:

$ touch filename

Modify content:

$ vi
$ vim
$ nano

$ mv src dest
$ cp src dest

u: user
g: group
o: other
a: all users

r: read, 4
w: write, 2
x: execute, 1

r: read structure
w: modify structure
x: access directory(as working directory)

$ chmod/ll
$ lsattr/chattr
$ umask

$ cd
$ pwd

Special notation:
. present directory
.. parent directory
~ home of present user
~user home of this user
/ root
- last working directory

$ mkdir [-P] path

With -P option, create parent path if not exist.

$ rmdir [-P] path

View previous commands(of present user):

$ history

Execute previous command:

$ !num
$ !!

Search command:

Ctrl + R