0   This course

1   Introduction

• History of Unix
  • Multics: high availability and scalability; many novel ideas, not a commercial success
  • Ken Thompson writes Unix in assembler for the PDP7; Dennis Ritchie writes the first C compiler; they rewrite Unix in C, beginning of portability and expansion
  • 80s: AT&T version (System V), and Berkeley version (BSD); industrial adoption and new branches
  • 1988: first POSIX standard
  • 1991: Linus Torvalds writes Linux and releases it as free software
  • Many Linux distributions appear
• The shell
  • Shells are are regular, ordinary processes
  • Internal and external commands; the command type
  • Commands history, alias.
  • Shell history and configuration files
• Getting help
  • help
  • man pages, man -k, see also section 5.3 of the tutorial

2   File System (i)

• Absolute and relative paths
• . and ..
• Physical organization of a typical Unix file system
  • Superblock
    • Magic number
    • Inode number of the / directory
  • Inode table, where each inode contains
    • Ownership
    • Access rights
    • Timestamps
    • File size
    • Link count
    • Pointers to disk blocks
  • After that, all data blocks
  • Directories are just special files that store a table of pairs (inode, filename)

3   File System (ii)

• hexdump and bzip
• Basics of regular expressions

4   Processes

• File descriptor table; /proc/PID/fd/
• Shell redirections
• Shell pipelines
• Environment; set, env
• Return code; variable $?
• Setuid and setgid bits for executables and directories
• Command ps, options

5   Network, Printers, Stream Editing

• netstat -tuanlp
• Priviledged ports
• ssh -XDv
• netcat -v www.google.fr 80
• netcat -vnl -p 1234

6   Text Editors

• Basic notions of vi

7   System Administration

• Sections of the manual:

  Section	Description
  1	General commands
  2	System calls
  3	Library functions, covering in particular the C standard library
  4	Special files (usually devices, those found in /dev) and drivers
  5	File formats and conventions
  6	Games and screensavers
  7	Conventions, Protocols, and Miscellanea
  8	Administration and priviledged commands and daemons

  See http://linux.die.net/man/

• System start-up

• users, groups, adduser, group, usermod

8   Shell scripting

• Many shells, we will focus on the Bash shell
• Shell variables and environment variables
• Command line substitution
• true, false, test, expr
• if, while, case
• set options
• signals