Users and Permissions

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Introduction to Linux in HPC/Users and permissions
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Tutorial
Title: Introduction to Linux in HPC
Provider: HPC.NRW

Contact: tutorials@hpc.nrw
Type: Multi-part video
Topic Area: HPC Platforms
License: CC-BY-SA
Syllabus

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 tutorial covers the concept of users (and groups) in the multi-user operating system Linux. It will also explain the various permissions that a file or directory can have, how to determine and change them. As an example, it will show how to make a Python script executable by the user.

Video

( Slides as pdf)

Quiz

Who can change the permissions of a file?

the owner of this file
every user
users in the same group

How is the top-level admin (or superuser) called in Linux?

god
guru
root

Which one of the following is not a file permission?

Write
Read
Execute
Size

Who can change the owner or group of a file?

the owner of that file
everyone in this group
admin (root)

Which command can prevent other users not in your group from writing to input.dat?

chmod u-w input.dat
chmod o-w input.dat
chmod g-w input.dat


Exercises in Terminal (slide 89)

1. List your home-directory, so that you can see users and permissions. Pick a file of your choice and explain 1) whom it belongs, 2) to which group it belongs and 3) what permissions all other users have for this file.


2. Create an empty file, make it read-only, make it executable.



<< Text Display and Search

Overview

Processes >>