ubuntu system

ubuntu是linux的发行版之一，从外观上分为有界面(ubuntu core)和无界面(ubuntu desktop)

download and install

八分钟完成VMware和ubuntu系统安装

connect to the Internect

VMware中Ubuntu联网方案（含泪试错版）

note: need to restart sometimes

adjust screen size

Settings -> Displays -> Resolution(16：9) -> Scale(300%)

change the direction of scroll mouse

Settings -> Mouse&Touchpad -> Natural Scrolling(close)

terminal

open terminal

ctrl + alt +T

root permission

for ordinary user

rani@deliwar:~$
// rani: name of user
// deliwar: name of host
// ~: current directory
// $: not root user

for root user

root@Deliwar:/home/rani#
// root: root user
// deliwar: name of host
// /home/rani: system dierctory
// #: super user

note: root user is needed in Embedded Development

get root permission:

sudo passwd
(type passward twice as required)
su root
(type passward once)

or:
sudo su
(type passward)

exit from root

exit

install/uninstall application

download application

prepation:

1.connect to Internet

2.set download source

Software & Updates -> Ubuntu Software -> download from(...mirrors...tsinghua...)

3.apt update

download application

apt install xx

upgrade application

apt upgrade xx

uninstall application

1.apt search x or apt-cache pkgnames x // x: several first letters of the application name

2.uninstall application

apt remove xx // remain configuration

or

apt purge xx // delete configation and package

3.apt autoremove is needed at last to clear useless realationships and packages

folder operation

show all the folders in current directory

ls

go to next directory

cd xx(dirname)

go to former directory

cd /home/...(dirpath)

create new folder

mkdir xx

delete folder

rmdir xx

VIM

vim is the enhanced version of vi

create or open a file

vim test.c // if test.c exists, open it; else create it

three modes

normal mode: operate directly

edit mode: edit

order mode: operate with orders

to normal mode:

esc

to edit mode:

i

to order mode:

: or ? or / (for different functions)

in order mode

some orders

:set number -> show line number
:wq -> save and exit
/ad -> find "ad" in current file
?ad -> find "ad" in current file

direction

cursor taks no effects in vim. key ↑ ↓ ← → is needed

or in normal mode:

h -> left
j -> down
k -> up
l ->righ

first line

gg

last line

G

specific line

ngg

copy and paste

in normal mode:

copy and paste any

(cursor go to start)
v
(cursor go to end)
y
(cursor go to new start)
p

copy and paste single line

(cursor go to start)
yy
(cursor go to new start)
p

copy and paste several lines

(cursor go to start)
nyy //n lines from start line
(cursor go to new start)
p

delete

in edit mode:

del / ←

in normal mode:

delete single line

dd

delete sevsral lines

ndd //delete n lines from start line

in order mode:

m,nd // delete from m line to n line

note: in order mode, "enter" is needed; while in normal mode not

undo and redo

in normal mode:

u //undo
ctrl + r //redo

find

/xx
n // find the latter one

?xx
n // find the former one

replace

:%s /old/new/g

save

:wq // save and exit
:q! // don't save and exit

comparision between two and more files

vimdiff file1 file2 file3