Forget your bird, Love Linux

Click on playground and roll on your sleeves :c) -

playground

There are four types of the shell, we have in Linux-

• Broune Shell -Sh shell
• C Shell - csh or tcsh
• Z shell -zsh

• My Favorite - Bourne again shell -bash

• To check shell type-

  echo #SHELL

• To print on the terminal

  echo Hi from terminal !!

• To view the current directory, display absolute path, means path from the root

  pwd

• To view all the files in a directory, -a will display hidden files as well

  ls
  ls -a

• To change directory, it is case-sensitive, and you have to type in the name of the folder exactly as it is.

  cd .. - To go back from a folder to the folder before that
  cd my_directory - to goto my_directory folder

• When folder name has space e.g. my bird

  cd my\ bird

• Create a new directory

  mkdir abhishek

• When folder name has a space e.g. abhishek sharma

  mkdir abhishek\ sharma

• make directory hierarchy from one command

  mkdir -p /dir_1/dir_2/dir_3/dir_4

• Run multiple commands in a single line

  cd abhishek\ sharma; mkdir devops_tools; ls

• Create a file

  touch file_1.txt

• Write content in the file

  cat > file_1.txt

• write anything, write- "this is my first file in Linux" and type Ctrl+d to save

• another way to do it

  echo "this is my first file in linux" > file_1.txt

• View content

  cat file_1.txt

• Remove directory and file commands

  mkdir removable_dir
  rmdir removable_dir
  mkdir removable_dir
  cd removable_dir; touch removable_file.txt
  rmdir removable_dir
  ---it gives you an error

• Notes: only blank directories can be deleted with rmdir; to delete a directory, which has content in it, we will use rm -r

  rm -r removable_dir

• To delete a file

  rm file_1.txt

• Copy commands-

• Copy a file to another file

  cp {options} source_file target_file
  cp new_file.txt copy_file.txt

• Copy File(s) to another directory or folder

  cp {options} source_file target_directory
  touch /dir_1/dir_2/file_4.txt
  cp -v /dir_1/dir_2/file_4.txt /dir_1/dir_2/dir_3/dir_4

• Copy directory to directory

  cp {options} source_directory target_directory

• To copy a directory from one place to another use -r or -R option in cp command

  cp -r /dir_1/dir_2/dir_3/dir_4 /dir_1/dir_2/

• If the destination directory already has the same file, still you want to copy that file, to overwrite it use *-i*

  cat > dir_1/dir_2/file_4.txt - this is me. press ctrl+d
  cp -i /dir_1/dir_2/file_4.txt /dir_1/dir_2/dir_3/dir_4

• Move command- mv command to move the files one place to another

  touch dir_1/dir_2/file_3.txt
  mv -v dir_1/dir_2/file_3.txt dir_1/dir_2/dir_3

• Rename filename

  touch latest.txt

• want to change this file name latest to new

  mv latest.txt new.txt
  rm latest.txt

• Search something

  locate new.txt

• if you want to ignore the case

  locate -i New.txt

• if you want a file that has the word "this"

  locate -i this

• If you want the file(s) that has words "this" and "me"

  locate -i *this*me

To view available disk space

df
above command will show disk space in KB, to view in MB use the following command
df -m

• To view disk usage by files

  du

• to view disk space used by a directory

  du dir_1

• To view Linux distro

  uname
  uname -a

• Package manager apt-get

  sudo apt-get update
  sudo apt-get install nginx -y

• To view your IP and name in host or network

  hostname
  hostname -I

• To know your user account

  whoami

• To view user id, group id, group etc.

  id

• Download a file from a link

  curl www.randomlink.com/downloadable-file.txt -O
  OR
  wget www.randomlink.com/downloadable-file.txt -O downloadable-file

• Service start/stop/enable/disable/restart/status

  systemctl status nginx
  systemctl restart nginx
  systemctl stop nginx
  
  systemctl status nginx
  systemctl start nginx
  systemctl disable nginx
  systemctl enable nginx

• To check connection to server

  ping {ip address}
  ping www.google.com

Bonus to read

1. Write clear to clean the terminal.
2. to autofill use TAB. Suppose you have a folder- my_folder and want to go to that folder, You just need to type cd my and then TAB and the terminal fills the rest up and makes it cd my_folder.
3. To stop a command write Ctrl+C
4. to force stop a command write Ctrl+Z
5. Write exit to exit from terminal