SetUp

• replace Raspberry Pi source list

sudo vi /etc/apt/sources.list
deb http://mirrors.shu.edu.cn/raspbian/raspbian/ stretch main contrib non-free rpi

• install Chinese input

sudo apt-get install fcitx fcitx-googlepinyin fcitx-module-cloudpinyin fcitx-sunpinyin

• tell which bash using

echo $0

https://stackoverflow.com/questions/3349370/how-to-tell-which-unix-shell-i-am-using

• use open command as on Mac

add this to ~/.bashrc

alias open = "xdg-open" 

https://stackoverflow.com/questions/3349370/how-to-tell-which-unix-shell-i-am-using

• shutdown Raspberry Pi

shutdown -r now #reboot
shutdown -h now #shutdown

• kill a not responding process

ps -a # list the running process
kill -p <pid>

• run commands from Python

import os
os.system('your command')

for example, we can write a shutdown script:

shutdown script

#!/usr/bin/env python
import os
os.system('shutdown -h now')

chmod u+x shutdown.py

---

Special Habits

• remap the Alt key to Control key

xmodmap -e "remove mod1 = Alt_L"
xmodmap -e "add control = Alt_L"

Or put

remove mod1 = Alt_L
add control = Alt_L

in modmap.file and then xmodmap modmap.file

---

Apps

• ReText

for markdown edit, install using sudo apt-get install retext

use it from Terminal : retext or find it under Office menu

• scrot

screenshot, install using sudo apt-get install scrot

use if from Terminal : scrot scort -s choose a rectangle to capture

---

Git

• git clone empty repo

$ git clone https://github.com/YOUR-USERNAME/YOUR-REPOSITORY

• git ignore files

touch .gitignore
# then add ignore files

• download single folder of github

# change /tree/master/ in URL to /trunk/, then use svn
svn checkout url

---

Vim

• change the comment blue color

change the comment blue color to LightBlue for better reading

hi Comment ctermfg = LightBlue

• set autoindent to 2 spaces

set autoindent
set shiftwidth=2

add this to ~/.vimrc

• copy all file contents

gg"*yG

https://stackoverflow.com/questions/1620018/copy-all-the-lines-to-clipboard

---

C

• binary numbers

though standard C doesn't represent binary representaion, but in gcc it supports

int foo = 0b00100101;

https://stackoverflow.com/questions/6413956/c-represent-int-in-base-2

---

Shell

• find file

ls -a can list all files, but we can combine with grep, such as:

ls -a | grep RE

we can find all the files who's file name have chars 'RE' inside.

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### Python

- change working directory

import os os.chdir('/home/pi/Downloads')