Introduction to Linux: Managing System Resources and User Permissions
This seminar offers a comprehensive introduction to Linux, focusing on its role as an open-source operating system inspired by Unix. Participants will learn how Linux manages hardware resources, provides a platform for applications, and supports multiple users with distinct permissions. The session covers essential commands, directory structures, and file permission levels, along with practical usage scenarios. Attendees will also explore various Linux distributions such as Debian, Ubuntu, and Fedora, while gaining insight into the Linux command line and shell operations.
Introduction to Linux: Managing System Resources and User Permissions
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Presentation Transcript
Linux Seminar by noname
System SW • Manage HW resources • Provide a platform for applications • Windows, Linux, Mac OS, iOS, Android, DOS, … Operating System?
OS • Made by Linus Torvalds • Inspired by Unix • Debian, CentOS, Ubuntu, Fedora, Redhat Linux, Gentoo, Arch, Suse, Slackware, Mandriva, PintOS, … Linux?
Custom • Free (in some sense) • Open source • Supports multiple users • Has compatibility with Unix-like OSs Why do we use Linux?
Normal users • Root • Sudoers • In SPARCS? • presparcs group • sparcs group • wheel group User & Group
Actually, both of them are files • Directory contains files • If filename starts with ‘.’ • Hidden • . • .. File & Directory
Three permission levels for each file • Owner(User) • Owner(Group) • Others • Slice it! • rwxrwxrwx • r-xr--rw- Permission
Tree structure • / • /home • /home/noname • /etc • /root • /bin • ~/ • ~noname/ • ~/public_html/ • … Directory Structure
Absolute path • /usr/bin/python • /usr/local/lib/python2.6/dist-packages/django/ • Relative path • public_html/crazy.png • Working directory Path
GUI • Gnome, KDE, … • CUI • Terminal Interface
Some kind of command line on terminal • Interacts with users • bash, sh, tcsh, ash, zsh, rc, … • bashrc Shell
Secure Shell • Protocol (in some cases, a program) • Default port number for ssh is 22 • Opens terminal ssh
Program • Supports connection via ssh/telnet • Simple & Easy, but convenient • Google ‘putty’ • or http://www.chiark.greenend.org.uk/~sgtatham/putty/ Putty
Basic Format • [command] [arg1] [arg2] … Commands
ls • ls [path] • ls –a • ls –l • ls –al • ls –a –l • ls -lh • cd • cd [path] Commands
pwd • rm [path] • rm –f [path] • rm –r [path] • rm –rf [path] • rm –rf / Commands
mkdir [path] • rmdir [path] • cat [path1] [path2] … • cat –n [path1] [path2] … Commands
cp [source1] [source2] [source3] … [destination] • cp -r [source1] [source2] [source3] … [destination] • mv [source1] [source2] [source3] … [destination] Commands
more [path] • less [path] • less > more Commands
passwd • passwd [username] • ps • ps aux • top Commands
wget [URL] • ssh sparcs.org • ssh noname@sparcs.org • scp noname@sparcs.org:~/public_html/siva.png ./kill/ • scp –r ./kill/ root@bit.sparcs.org:~/ Commands
wc [path1] [path2] … • grep [word] [path] • grep대한 애국가.txt • grep –R [word] [path] • egrep Commands
chmod 744 [path] • chmod 512 [path] • chmod –R 777 [path] Commands
tar –zxvf [path] • tar –zcvf [destination] [path1] [path2] … • tar –xvf [path] • tar –cvf[destination] [path1] [path2] … Commands
df • df -h • kill [pid] Commands
man [command] Commands
E way edojonnamanayo • ln, chown, su, sudo, fg, bg, jobs, echo, export, killall, skill, nohup, shutdown, reboot, wall, yes, chsh, man, apropos, umask, chroot, clear, … Commands
? for one character • * for undecided number of characters • It works for all matching files Wildcard Character
[command1] | [command2] | [command3] | … • ls –al | egrep ‘^d’ • ls –al | egrep ‘^d’ | wc • [command] > [path] • [command] < [path] • [command] >> [path] • [command] 2> [path] Pipe & Redirection
!foobar… • Ctrl + r • Ctrl + d • Ctrl + l • Ctrl + a • Ctrl + e • Ctrl + u • Ctrl + c • Ctrl + z • Ctrl + \ Techniques
Mouse drag • Mouse right click • Duplicate Session • Change Settings • Special Command Putty Techniques
setuid, setgid, sticky bit, environment varilables, signal, … Etc..
