Command-Line.md

Command Line:

• an essential tool for software development.
• useful to execute a wide variety of programs on your computer.
• a tool for interacting with a computer using text (also known as a text interface).

Unix Commands is a type of command that is used in Linux and macOS.

Commands are instruction given to the computer into what is called a terminal.

• NOTE: 1. For Windows we use POWERSHELL or GIT BASH.

• NOTE: 2. Here we will use the word directory (plural: directories) in place of folder often. They both are the same thing, and they're used interchangeably.

Commands:

• start . (for windows) or open . (for Linux/macOS)

  • Opens File Explorer where we use GUI to manipulate the Files or Folders/Directories.

• pwd

  • stands for Print Working Directory.
  • On command line, it is important to know the directory you're working. Here comes pwd command to check that.
  • When you execute the pwd command, all the directories from the root directory to the current directory are displayed.

• ls

  • when moving between directories, it would be convenient if we could see the list of files and directories in the current directory. ls command is used for same.
  • it is important to note that ls command will only display the files and directories that are direct children of the current directory.
  • to read hidden files give command: ls -a

• cd

  • stands for Change Directory.
  • if you execute cd without specifying a directory or cd ~, you can move to what is called a home directory.

  i. cd directory_name command helps you to move to other specified directory.

  ii. cd .. command let you move back to your previous folder.

• mkdir directory_name

  • you can create a new directory using mkdir directory_name command as well.

• touch filename.extension

  • you can create an empty file of any type.

• cat filename.extension

  • it displays the text content of the file.

• cp file_to_copy new_file_name

  • used for coping files.

• cp -r directory_to_copy new_directory_name

  • used for coping directories.
  • -r stands for recursive function.
  • important: not applying -r will result to an error and the command will not be executed.

• rm filename.extension

  • used for deleting files.

• rm -r directory_name

  • used for deleting non-empty directory.

• rmdir directory_name

  • used for deleting empty directory.

Tips & Tricks:

• ctrl + l clears the terminal.
• tab helps for auto-completion.
• ~ means you're in root or home folder/directory.
• $ sign denotes it's a command at any site you check.
• up and down arrows help you to get the command history to use it again as a new command.