Linux and Unix Fundamentals (LPI 101/102)

Introduction

• What Linux is, Unix philosophy
• Unix History
• Unix Standards
• Linux distributions
• Other Unix: BSD, Solaris, AIX, OS/X, ...
• Unix/Linux Scalability
• Unix Licensing: proprietary and Open Source
• Logging in, typing commands, logging out
• Files, directories and paths
• Creating files with a text editor
• Viewing files (cat, less)
• Managing files (cp, mv, rm)
• Magic dot files and hidden files
• Absolute & relative paths
• Filename generation: wild cards
• Managing directories (mkdir, rmdir)
• Documentation for commands (man)
• Useful shell features (command-line editing, file name completion, history)

The Unix and Linux command line

• Unix shells (bash)
• Command line syntax (options, arguments)
• Shell variables and environment variables
• Command substitution
• STDIN, STDOUT & STDERR
• Using pipes to connect programs
• Useful text filters (wc, sort, uniq, expand, head, tail, nl, tac)
• Spitting files across disks (split)
• Finding files
• Using redirection to connect programs to files
• Redirect into files with append (>>)

Documentation

• The unfortunate diversity of Linux documentation
• Using man(1)
• How man pages are divided among ‘sections’
• Searching for man pages (whatis, apropos, man -k)
• Printing man pages (man -t)
• Documentation for shell builtins (help)
• Using GNU info documentation (info)
• Documentation under /usr/share/doc

Text editing with Vi

• Unix is all about text
• Vi: the standard Unix editor
• The concept of ‘modes’ in a modal editor
• Vi clones, extensions to vi
• Other powerful Unix text editors
• Practical work learning Vi and Vim

Configuration Files

• Configuration Files
• Shell Configuration Files
• Changing Environment Variables
• Changing the Shell Prompt
• Other Useful Variables
• Shell Aliases
• Binding Keys with Readline

Processes and jobs

• What processes are
• The properties of a process
• Parent processes and child processes
• Job control (fg, bg, jobs)
• Suspending processes (Ctrl+Z)
• Running programs in the background (&)
• Long-lived processes (nohup)
• Monitoring processes (ps, pstree, top)
• Killing processes and sending signals a process (kill, killall, xkill)
• Process niceness/priority (nice, renice)

Searching Text Files Using Regular Expressions

• Using Regular Expressions
• grep Command Line Options
• Pattern Matching basics
• Regular Expression Examples
• Alternation and Grouping
• Extended Regular Expression Syntax
• sed
• Line Selection with sed

Scheduling

• Running commands at particular times (at, atq, atrm)
• Scheduling commands to run repeatedly (cron)
• Different ways of configuring cron (/etc/crontab, etc)
• User crontabs (crontab command)
• Output of cron & at jobs
• At Command and Cron Job Permissions

File system concepts and use

• The unified Unix file system
• The Filesystem Hierarchy Standard
• What is a filename ?
• Shareable and Non-Shareable Data
• Static and Dynamic Data
• Special file types
• Devices, fifos, Unix domain sockets /dev and /sys on Linux
• Conceptual View of a Unix Filesystem layout on disk
• Symbolic links (ln -s)
• Inodes and directory entries
• Hard and Symbolic/soft links
• Preserving links while copying and archiving
• finding programs with which and type

Archiving and Backups

• Compressing Files with gzip
• Other Compression Tools
• Archiving Files with tar
• Listing and extracting the Files in tar Archives
• Backup Media
• Types of Backup and Strategy
• What Not to Backup
• Device Files for Accessing Tapes
• Controlling Tape Drives with mt
• Other Backup Software

Managing User Accounts

• Users and Groups /etc/passwd & /etc/group
• Shadow Passwords and Groups
• Changing user passwords
• Adding new users
• Setting Up Home Directories for New Accounts
• Removing users
• Modifying users
• Locking Accounts
• Managing groups chsh /etc/nsswitch.conf
• PAM — Pluggable Authentication Modules

Filesystem security

• Users and groups
• The ‘root’ user, or superuser
• Configuring sudo
• Changing file ownership (chown)
• Changing file group ownership (chgrp)
• More complex ways of changing ownership (recursively, changing owner and group simultaneously)
• Examining permissions with ls -l and stat
• Permissions on files
• Permissions on directories
• Setuserid, setgroupid & sticky permissions
• How permissions are applied
• Changing permissions (chmod)
• The special ‘sticky bit’ mode on directories
• Setgid and setuid permissions, their effect on files and directories
• Default permissions for new files (umask)
• Access Control Lists (ACLs)

Creating Partitions and File systems

• Buffer cache & sync command
• Disks, partitions, individual file systems and Filesystem types
• Naming of disk and partition devices (/dev/hda, etc)
• Creating and deleting partitions (fdisk)
• Raid and Mirrors
• Logical Volume Management
• Resizing a partition
• Mounting and unmounting file systems (mount, umount, /etc/fstab)
• Mounting a file — loopback
• Disk labels
• Swap space
• Checking available free space and space used by files (df, du)
• Checking and correcting the integrity of file systems (fsck)
• Journaling file systems, ext2, ext3 & ext4

Booting and runlevels

• The boot process: from BIOS to kernel to userspace
• Setting kernel parameters
• Configuring a boot loader: LILO and Grub
• Runlevels and init scripts
• Configuring services to run at boot
• Securing single-user mode (sulogin)
• Determining and changing run level
• Shutting down and rebooting the system
• Starting and stopping individual services
• Service Management Facility (SMF) & upstart systemd — the new init

Logging System Events

syslog daemon /etc/syslog.conf

• Examining Logs: tail & less and grep
• Linux Kernel Messages rsyslog — the new syslog
• Log Rotation, sample /etc/logrotate.conf

Advanced shell usage

• Quoting (single quotes, double quotes, backslashes)
• Combining quoting mechanisms
• Globbing patterns (*, ?, [])
• Generating file names and other text with {} braces
• The tee command

Installing software

• Managing software installation (advantages of package management)
• Debian package management:
• • Package naming and version numbering
  • Searching for packages (apt-cache)
  • Using Apt to get and install packages (apt-get)
  • Low-level package management (dpkg)
• Red Hat package management:
• • Installing and upgrading RPM packages (rpm and yum)
  • Which packages are installed, which package a file came from
  • Examining RPM package files
  • Verifying integrity of the installation yum configuration

Making and Installing Programs from Source

• Obtaining Source Packages
• Unpacking Archives
• Running the configure Script
• Using make to Build Software and install it
• Choosing Where to Install Software

Managing Shared Libraries

• Executables and Libraries
• Library Files and Linking
• Using the ldd Command
• Finding Libraries
• Using ldconfig
• Static Linking

The Linux kernel

• What the kernel is and does
• Kernel modules (lsmod, modprobe, rmmod)
• Module dependencies (depmod)
• Examining modules (modinfo)
• Configuring kernel modules (/etc/modprobe.conf)
• Commands in modprobe.conf
• Recompiling the kernel
• Configuring, compiling and installing the kernel and modules (make menuconfig, make xconfig, etc)
• Loading and unloading kernel modules (lsmod, modprobe, rmmod)
• Creating the initial root disk

The X window system

• What X is
• The rôle of window managers and desktop environments
• Startup and session scripts
• Terminal emulators (xterm, etc)
• Configuring X Under Debian and Red Hat

Shell scripting and configuration

• The point of shell programming
• The ‘she-bang line’ (#!/bin/sh)
• Outputting text with (echo)
• Reading input (read)
• Writing simple shell functions
• Sourcing files
• Command substitution again
• Conditional execution (||, &&, if, else) case — multi way branch
• Looping (for, while, seq)
• Infinite loops (while true)
• Testing for the existence and type of files (-f, -d, etc)
• Sending email from scripts (mail)

Awk and Perl

• Scripting languages: shells and dynamic awk variables, user and predefined awk patterns and actions awk functions perl variables and constants, user and predefined
• Example perl scripts: who is logged in, database use, networking

TCP/IP networking configuration

• Overview of modern TCP/IP networking, rôles of IP, TCP, UDP and ICMP
• Domain names and IP addresses (host, dig)
• Port numbers (/etc/services)
• Network interfaces (ifconfig, ifup, ifdown)
• Kernel routing tables (route)
• Configuring interfaces under Debian and Red Hat
• Finding and setting the hostname (hostname, /etc/hostname)
• DHCP client hosts
• Network diagnostics (ping, traceroute, netstat)

Linux network services

• Overview of network services under Linux, operating daemons
• Sending signals to daemons
• The advantages and disadvantages of using inetd and xinetd, basic configuration of both
• Secure Shell: ssh and sshd

Internet Daemons and Services

• Configuring the resolver libraries /etc/hosts & /etc/resolv.conf
• Structure of domain names, registering names (whois)
• Running a DNS server (BIND), setting up a caching-only name server, /etc/named.conf
• Running an MTA (email server)
• Email clients (MUAs)
• Basic configuration of Exim
• Routing mail with MX (mail exchanger) DNS records
• Mail aliases
• Fetching Mail with fetchmail
• Webservers: apache configuration file
• Configuring named virtual hosts
• Dynamic web pages
• Logging in Apache

Networked file systems

• Configuring NFS (/etc/exports, /etc/fstab)
• Viewing Exports (showmount, portmapper & rpcinfo)
• Mounting remote file systems
• Basic Samba configuration (smb.conf, SWAT)