File/Folder

touch filename
mdkir foldername

Move

cd -      : go to previous directory
cd / cd ~ : go to home directory

Type

• C-u : delete all line
• C-w : delete word

Search 搜尋

• ctrl + r type keyword to search history command
• !! <Enter>

grep -r "keyword" .

# brew install ripgrep
rg <word>

# 在多層目錄中找到filename.txt的路徑
find . -name {filename.txt}

Kill process running port

lsof -i:3000
kill <PID>

目錄大小

du -sh <path>

ssh

ssh {url} -l {login_name} -p {port} 

wget

wget {url} 把檔案抓下來

netcat

TCP/IP 瑞士刀 (Swiss Army Knife)

nc <host> <port>

nc example.com 12345

import socket

s = socket.socket()
s.connect(("example.com", 12345))

while True:
    data = input("> ")
    s.send(data.encode())

    response = s.recv(4096)
    print(response.decode())

strings

把binary file -> string

strings -a -t x file
-a   : all
-t x : 十六進位顯示

讀檔

open('dictionary.txt', 'rb').read()
open('dictionary.txt', 'r').read().splitlines()
open('dictionary.txt', 'rb').read().decode('utf-8')

更改權限

chmod +x filename

# read    r 4
# write   w 2
# execute x 1