Unix and Linux - Yousef's Notes

#History

Developed at At&T Bell Labs in the early 1970s.

1960 - 1st version in a PDP computer 1973 - Rewritten in C 1970s - Distribution to universities 1983 - System V - BSD releases 1980s - POSIX 1991 - Linux 1990s minix was the only open source os at that time

BSD more stable and more restrictive (licensing) OS than linux. Linux completely open and free but less stable. That’s why Apply chose to use BSD as the base for Darwin, and not Linux.

C Language
“everything is a file”
Open Source movement (GNU/Linux)

#X-Window

First graphical user interface. The OS is called a server (it serves the keyboard, screen, mouse, hardware). Application running is the client.

#Unix to Linux Transition

Minix, open source OS before Linux
Emergence of Linux in 1990s
Role of GNU project and Free software foundation
- GNU created free software like GCC and glibc
- Linux Kernel + GNU software made a fully functional operating system.

#Linux Versions

Which distribution to download? depends on needs (e.g. flexibility, purpose)
Client or Server?
LTS (Long-term support)

#Basic Unix/Linux Commands

Importance of command-line interface in Unix/Linux.

ls
cd
pwd
mkdir
rm

#Unix/Linux Filesystem

#Structure

Root directory
Home directories
System directories
Pathnames (absolute vs relative)
Navigating directories using commands.

#File types

Regular files
Directories
Symbolic links
Device files

File permissions: Read, write, execute.

Changing file permissions and ownership.

#Filesystem Hierarchy

Root Directory
Home Directories
System Directories