Reading notes 02

The Command Line

What are command lines?

• A command line, or terminal, is a text based interface to the system.
• A command line presents you with a prompt as you type.

Example of a command line

1. user@bash: ls -l /home/ryan
2. total 3
3. drwxr-xr-x 2 ryan users 4096 Mar 23 13:34 bin
4. drwxr-xr-x 18 ryan users 4096 Feb 17 09:12 Documents
5. drwxr-xr-x 2 ryan users 4096 May 05 17:25 public_html
6. user@bash:

Line 1

• Presents us with a prompt ( user@bash ).
• ( ls ) a command that you usually input first.
• After that are command line arguments ( -l/home/ryan )
• Important Note!!! There has to be space between the command line and the first command line argument.
• First command line arguement is ( -l ) also referred to as an option.
• Arguements typically start with a dash ( - ).

Lines 2 - 5

• Lines 2 - 5 are output from running the command.
• Most commands produce output and will be listed straight under the issuing command.
• Other commands perform their task and don’t display information unless there was an error.

Line 6

• Line 6 presents us with a prompt again.
• After the command has run, it means the terminal is ready for another command.
• If no prompt is displayed it means the command is still running.
• Note to self, on your terminal there wont be any line numbers on it. This is an example to make it easier.

Opening a Terminal

• When opening a terminal every system is different, but fairly easy.

  Mac Os

• Find the Terminal under Applications -> Utilities.
• A short cut can be a key combination of command + space.

  Linux

• Find it in (Applications -> System) or (Applications -> Utilities).
• Alternative way is to right-click on the desktop and there will be an option Open in terminal.

  Windows

• For windows it should be the same as Linux.
• But if you intend to remotely log into another machine then you’ll need an SSH client.
• A good SSH client is Putty and it’s also free!