Command Line (Linux)

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Introduction to Linux in HPC/The Command Line
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Title: Introduction to Linux in HPC
Provider: HPC.NRW

Type: Multi-part video
Topic Area: HPC Platforms
License: CC-BY-SA

1. Background and History
2. The Command Line
3. Linux Directory Structure
4. Files
5. Text display and search
6. Users and permissions
7. Processes
8. The vim text editor
9. Shell scripting
10. Environment variables
11. System configuration
12. SSH Connections
13. SSH: Graphics and File Transfer
14. Various tips

This part of the tutorial introduces one of the most important tools in Linux-based systems: the command line. The command line is basically a text interface for your computer and it can be pretty daunting at first if you are used to a graphical user interface (GUI). This short tutorial explains the basics enabling you to get started straight away!


( Slides as pdf)


Which keys can be used to access the command history?

up- and down-arrow keys
page-up and page-down keys

Which character do command line options conventionally start with?

the dollar sign
the dash sign (hyphen)
the greater-than sign

What happens if the control and c keys (Ctrl+C) are pressed simultaneously on the command line?

the current command is aborted
a script starts running in the shell
highlighted text is copied to the clipboard

Which one of these is not (normally) an element of the console prompt statement?

working directory
user name
host name
time and date

How can I list all available commands if I don’t know the exact name of the command, for example?

press the enter key
read the man pages
press the tab key
use the --help option

Info:  Working directory in console reminds user, where they are. (page 27)

Warning:  In command line user may forget where they are. (page 26)
Child processes may stop, if parent shell exits. (page 26)

Exercises in Terminal

1. What's your username on a Linux computer?
  There are two ways to find your username on a Linux computer 
2. What's the hostname of a Linux computer?
  There are two ways to find the hostname on a Linux computer.
3. What's your current working directory on a Linux computer?
   There are two ways to find your current working directory on a Linux computer.
4.  Use up- and down- (↑ and ↓) arrow keys to see the command history.
5.  Run sleep 1h command and wait, then use Ctrl-C to kill it.

<< Background and History


Linux Directory Structure >>