Command line basics

The shell is a textual interface to interact with the machine. You can do everything on your computer from the shell, no need for a graphical interface.

I am going to present here the basic commands to navigate in the shell and execute actions like reading or creating files/directories.

Navigate in the shell

The directories are separated by / on Linux and Mac os and \ on Windows. The path / is the root of the file system, on Windows each disk partition have its root.

Two kinds of path:

• relative path (relative to the current working directory)
• absolute path (start with /, the root)

to see your current working directory pwd (print working directory)

to change directory cd directory: change directory

. refers to the current directory .. refers to the parent directory cd - brings you back to the directory you were

to list the content of a directory: ls ls print the content of the current directory, unless you give him a directory as its first arguement ls /home

you can use the -l option with ls to list the content of a directory using a long listing format

clear to clear the terminal

Creating and moving

mv to rename / move a file cp to copy a file mkdir create a new directory mkdir -p to create a directory with nested directories touch to create a file

Get help for a command

Most of commands have a lot of options available, you can’t know all of them. You can get help by two ways directly from the shell.

Manual

To get more informations about the command you want to use, use the man program, following by the command name. It will display the manual of the command. Use the arrows keys up and down to navigate line by line or space and B to navigate page by page. Press q to quit. Press / and type the term you want to seach and use n and Shift N to navigate through the occurences of this term.

Help

command --help To display essential informations about the command, shorter than the manual.