Difference between revisions of "Introduction to Linux in HPC/The Command Line"
Introduction to Linux in HPC/The Command Line
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| − | 1. In the command line prompt, e.g. [username@hostname ~]$ , you can find your username as username directly. | + | 1. In the command line prompt, e.g.<code>[username@hostname ~]$</code> , you can find your username as username directly. |
| − | 2. The Linux command whoami can also show your username. | + | 2. The Linux command <code>whoami</code> can also show your username. |
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2. What's the hostname of a Linux computer? | 2. What's the hostname of a Linux computer? | ||
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| − | 1. In the command line prompt, e.g. [username@hostname ~]$ , you can find the hostname as hostname directly. | + | 1. In the command line prompt, e.g. <code>[username@hostname ~]$</code> , you can find the hostname as hostname directly. |
2. The Linux command hostname can also give you the hostname. | 2. The Linux command hostname can also give you the hostname. | ||
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| − | 1. In the command line prompt, e.g. [username@hostname ~]$ , you can find your current working directory is ~, which means your $HOME directory. | + | 1. In the command line prompt, e.g. <code>[username@hostname ~]$</code> , you can find your current working directory is <code>~</code>, which means your $HOME directory. |
| − | 2. The Linux command pwd can also show your current working directory. | + | 2. The Linux command <code>pwd can also show your current working directory. |
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Revision as of 10:32, 2 October 2020
Video
Linux Introduction Slides 25 - 31 (7 pages)
Slide Layout
page 1:
You type commands in command line to use Linux
Similar things: console, terminal, CLI and shell (interchangeable in this course)
command line: advantages (fast) vs. disadvantages (hard to master)
page 2:
Shell in Linux is widely used.
Warnings:
User may forget where they are.
Child processes may stop, if parent shell exits.
page 3:
Elements in console:
User name
Host name
Working directory: reminder for user (where they are)
Command prompt
page 4:
Elements in console (cont.):
Command and its options
Output
Current command running or new command prompt
page 5:
Demo 1: (slide 15 sec + terminal 45 sec)
run command
arrow keys for history
tab key for auto-completion
Ctrl-C to abort
page 6:
Warning: command is always case-sensitive
command line options: minus sign: double minus vs. single minus
page 7:
Demo 2: (slide 15 sec + terminal 30 sec)
use internet for help
man page
built-in help
Quiz
Which keys can be used for command history?
| Info: | Working directory in console reminds user, where they are. (page 3) |
| Warning: | In command line user may forget where they are. (page 2) Child processes may stop, if parent shell exits. (page 2) |
Exercises in Terminal
1. What's your username on a Linux computer? There are two ways to find your username on a Linux computer
| Answer: |
1. In the command line prompt, e.g. |
2. What's the hostname of a Linux computer? There are two ways to find the hostname on a Linux computer.
| Answer: |
1. In the command line prompt, e.g.
|
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.
| Answer: |
1. In the command line prompt, e.g.
|
4. Use up- and down-arrow keys to see the command history.
| Explanation: |
The up- and down- arrow keys can be used to navigate command history. |
5. Run sleep 1h command and wait, then use Ctrl-C to kill it.
| Explanation: |
sleep 1h puts the terminal into idle, e.g. terminal is doing nothing, for 1 hour.
Ctrl-C kills the current command. In this exercise it's sleep 1h.
|