Basic command lines

Chosen linux commands and how to use them ! (not all options are listed)

cat

To concatenate files or print files.

• cat [file]

chmod

Change file or folder access rights.

• chmod g-w [file_name] -> remove write permission to group
• chmod u-wr [file_name] -> remove read and write permission to user

chown

Change file owner.

• chown root [file_name] -> make root the owner of the file

docker

Access a bash shell inside a docker container

• docker exec -it [container_name] bash

grep

Filter folders, files or text based on a given set of characters.

• grep -n "[characters]" [file_name]
• grep -o "[pattern]" [path/to/file] | wc -l -> count occurences of a pattern in a file

ln

Create a symlink.

• ln -s [target_file] [symlink_name]

ls

List files and folder at given path.

• ls -l (one file one line view) -a (list all files, even hidden ones) [path/to/file-folder]

mv

Move a file or a folder into a target folder.

mv [source_folder/file] [target_folder]

nano

Command line text editor.

nano [file_name]

^X -> Exit

netstat

Access server information: ports, processess, PID netstat -laputen

rm

Remove some specified files. rm -f (force) -r (recursive) -v (verbose)

scp

Exchange files between servers and computers.

• scp -i [key_path] [path/file_to_be_transfered] [path/file_destination]
• for instance, when connecting to AWS ubuntu instance : ubuntu@[server_public_DNS]:[path_in_server]

sed

(among others) remove first lines of a file

• sed -i [startIndex],[endIndex]d [file_name]

sudo

Change users and rights.

• sudo su -> activate superuser type 'exit' to exit

ssh

Connect to another machine.

• ssh -i [path/key] [user_name]@[other_machine_DNS]
• ssh [server_name]

tar

To create or decompress an archive.

• options:
  • c create
  • x decompress
  • f use a specified file
  • v verbose mode
  • z for Gzip archives
• tar xzfv [path/to/file] -> decompress a given archive in the current directory

timux

Manage several terminal windows.

• tmux -> start a new session
  • In tmux, ctrl+b and then % -> vertical split
  • In tmux, ctrl+b and then " -> horizontal split
  • In tmux, ctrl+b and then c -> new window
  • In tmux, ctrl+b and then d -> return to classic shell (dettach)
• tmux kill-session -t [session_id]

See https://gist.github.com/henrik/1967800

VBoxManage

Obviously, manage VirtualBox.

• VBoxManage list runningvms
• VBoxManage list vms
• VBoxManage controlvm <name|uuid> savestate -> gently power off vm (saving data)
• VBoxManage controlvm <name|uuid> poweroff -> not-gently power off

vim

Use vim text editor.

• :q! -> exit without saving
• :wq -> write and quit
• :%s/<pattern>/&/gn -> count the number of occurences of <pattern> in the file
• :%s/<word1>.*<word2>/&/gn -> count the number of occurences for a pattern word1...(any sequence of characters)...word2, the order word1 word2 matters

Configure new computer

• update

  sudo apt-get update && sudo apt-get upgrade

• git (required for oh my zsh)

  sudo apt-get install git

• zsh

  sudo apt-get install zsh

• oh-my-zsh

  sh -c "$(wget -O- https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"

• vim

  sudo apt-get install vim

• tmux

  sudo apt-get install tmux

• docker install doc ubuntu and proceed with postinstall

• docker compose install doc

• install pip3 and others

  sudo apt install python3-pip pip3 install virtualenv python3 -m pip install jupyter

• install yarn

configure the repository:

curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add - echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list

then enter:

sudo apt-get update && sudo apt-get install yarn

• install nvm (with zsh shell)

  curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.34.0/install.sh | zsh