A command-line interface (CLI) is a way to interact with a computer's operating system by typing commands into a terminal.

Structure

❯❯❯ $ command ${options} ${arguments}

# e.g.
❯❯❯ $ ls -la /document/photo 

• command
  • The action to be executed.
• options
  • These are optional options (or flags) that modify the command's behaviour.
• arguments
  • These are the required or optional arguments that use to specify the target. The format of arguments depend on the each command.

Shortcut

Directory management

pwd

• check the current directory

~/Desktop ❯❯❯ pwd
/Users/user/Desktop

mkdir

• make new directory

~/Desktop ❯❯❯ mkdir myDir

cd

• change directory

# change directory to myDir
~/Desktop ❯❯❯ cd myDir
# change directory one level up in the hierarchy
~/Desktop ❯❯❯ cd ..
# change directory to home
~/Desktop ❯❯❯ cd

File operations

ls

• list files and directories
• -a: list all files including hidden file starting with '.'
• -l: list with long format (permissions)
• -t: sort by time and date
• -d: show only the directories

~/Desktop ❯❯❯ ls -lat
total 2992
drwxr-xr-x+ 54 user  staff    1728  6 Sep 16:30 ..
drwx------@  9 user  staff     288  6 Sep 16:28 .
drwxr-xr-x@ 2 user  staff      64  6 Sep 16:28 newDir
-rw-r--r--@ 1 user  staff       0  6 Sep 16:25 file1.txt
-rwx------@ 1 user  staff  321110  6 Sep 14:04 file2.txt
-rwx------@ 1 user  staff  363448  5 Sep 08:46 file3.txt
-rwx------@ 1 user  staff  835488 26 Aug 11:21 file4.txt

cp

• copy files
• -r: copy directories recursively
• -p: preserve the attributes (mode,ownership and timestamps)

~/Desktop ❯❯❯ cp -r originalDir copyDir

rm

• remove files and directories
• -r: delete directories recursively
• -f: Ignore nonexistent files, and never prompt before removing
• -i: Prompt before removal
• -d: delete empty directories

~/Desktop ❯❯❯ rm -d originalDir

mv

• rename or move files and directories to another location
• Adding a -v flag is to print source/destination directory

~/Desktop ❯❯❯ mv -v original.txt new.txt
original.txt -> new.txt

other

man

• view manual pages for Unix commands
• press q to exit

~/Desktop ❯❯❯ man ls
LS(1)                       General Commands Manual                      LS(1)

NAME
     ls – list directory contents

SYNOPSIS
     ls [-@ABCFGHILOPRSTUWabcdefghiklmnopqrstuvwxy1%,] [--color=when]
        [-D format] [file ...]

DESCRIPTION
     For each operand that names a file of a type other than directory, ls
.
.
.

clear

• clear screen
• shortcut is Ctrl + k

history

• show history of previous commands

  300  ls -lat
  301  pwd
  302  cd
  303  man ls

★　extra tip!　★

If you want to make sure a prompt always appears before deleting files you can create alias by changing configuration file.

• .bashrc: Bash shell
• .zshrc: Zsh shell

~ ❯❯❯ echo 'alias "rm=rm -i"' >> ~/.zshrc