Outline of Linux Phrasebook, 2nd Edition

Intro

1 Things to Know About Your Command Line

• Everything Is a File
• Maximum Filename Lengths
• Names Are Case-Sensitive
• Special Characters to Avoid in Names
• Wildcards and What They Mean
• Special Files That Affect Your Command Line
• If There’s Too Much, Reset clear

2 The Basics

• List Files and Folders ls
• List the Contents of Other Folders ls
• List Folder Contents Using Wildcards ls *
• View a List of Files in Subfolders ls -R
• View a List of Contents in a Single Column ls -1
• View Contents As a Comma-Separated List ls -m
• View Hidden Files and Folders ls -a
• Visually Display a File's Type ls -F
• Display Contents in Color ls --color
• List Permissions, Ownership, and More ls -l
• Reverse the Order Contents are Listed ls -r
• Sort Contents by File Extension ls -X
• Sort Contents by Date and Time ls -t
• Sort Contents by Size ls -S
• Express File Sizes in Terms of K, M, and G ls -h
• Display the Path of Your Current Directory pwd (also pwd -L & pwd -P)
• Change to a Different Directory cd
• Change to Your Home Directory cd ~
• Change to Your Previous Directory cd -
• Change a File to the Current Time touch
• Change a File to Any Desired Time touch -t
• Create a New, Empty File touch
• Create a New Directory mkdir
• Create a New Directory and Any Necessary Subdirectories mkdir -p
• Copy Files cp
• Copy Files Using Wildcards cp *
• Copy Files Verbosely cp -v
• Stop Yourself from Copying over Important Files cp -i
• Copy Directories cp -R
• Copy Files As Perfect Backups in Another Directory cp -a
• Move Files and Folders mv
• Rename Files and Folders mv
• Delete Files rm
• Remove Several Files At Once with Wildcards rm *
• Stop Yourself from Deleting Key Files rm -i
• Delete an Empty Directory rmdir
• Remove Files and Directories That Aren't Empty rm -Rf
• Delete Troublesome Files
• Become Another User su username
• Become Another User, with His Environment Variables su -l
• Become root su
• Become root, with Its Environment Variables su -
• REMOVED
  • Find Out What mkdir Is Doing As It Acts mkdir -v
  • Remove Files Verbosely rm -v

3 Learning About Commands

• Find Out About Commands with man man [command]
• Quickly Find Out What a Command Does Based on Its Name man -f, man --whatis
• Search for a Command Based on What It Does man -k, man --apropos
• Read a Command's Specific Man Page man [1-8]
• Learn About Commands with info info
• Navigate Within info
• Locate the Paths for a Command's Executable, Source Files, and Man Pages whereis
• Find Out Which Version of a Command Will Run which
• Discover How a Command Will Be Interpreted type
• REMOVED
  • Rebuild man's Database of Commands man -u
  • Print man Pages man -t
  • Read Descriptions of Commands whatis
  • Find a Command Based on What It Does apropos

4 Building Blocks

• Run Several Commands Sequentially ;
• Run Commands Only If the Previous Ones Succeed &&
• Run a Command Only If the Previous One Fails ||
• Plug the Output of a Command into Another Command $()
• Understand Input/Output Streams
• Use the Output of One Command As Input for Another |
• Redirect a Command's Output to a File >
• Prevent Overwriting Files When Using Redirection set -o noclobber
• Append a Command's Output to a File >>
• Use a File As Input for a Command <
• Combine Input and Output Redirection < >
• Send Output to a File and to stdout at the Same Time tee

5 Viewing Files

• Figure Out a File's Type file
• View Files on stdout cat
• Concatenate Files to stdout cat file1 file2
• Concatenate Files to Another File cat file1 file2 > file3
• Concatenate Files and Number the Lines cat -n file1 file2
• View Control Characters in a File cat -vet
• View Text Files a Screen at a Time less file1
• Search Within Your Pager
• Edit Files Viewed with a Pager
• View the First 10 Lines of a File head
• View the First Several Lines of a File or Files head -n
• View the Last 10 Lines of a File tail
• View the Constantly Updated Last Lines of a File or Files tail -f

REMOVED 6 Printing and Managing Print Jobs

6 Manipulating Text Files

• Count the Number of Words, Lines, and Characters In a File wc
  • Also wc -w, wc -l, & wc -c
• Number Lines In a File nl
  • Also nl -t & nl -a
• Format a file so it's more readable fmt
• Select an Entire Column of Data in a Delimited File cut
• Join Files Into Sequential Columns paste
  • Also paste -d
• Sort the Contents of a File sort
  • Also sort -n, sort -r, & sort -k
• Sort the Contents of a File Numerically sort -n & sort -g
• Remove Duplicate Lines In a File uniq
  • Also uniq -i
• Compare Two or More Files To See What’s Changed diff -u
• Substitute Selected Characters with Others tr
• Delete matching characters tr -d
• Replace repeated characters with a single instance tr -s
• Find & Replace Text In a File sed -i
• Print Specific Fields In a File awk

7 Ownership & Permissions

• Change the Group Owning Files and Directories chgrp
• Recursively Change the Group Owning a Directory chgrp -R
• Change the Owner of Files and Directories chown
• Change the Owner of Files and Directories Based on the Current Owner chown --from
• Change the Owner and Group of Files and Directories chown owner:group
• Understand the Basics of Permissions
• Change Permissions on Files and Directories Using Alphabetic Notation chmod
• Change Permissions on Files and Directories Using Numeric Permissions chmod
• Change Permissions Recursively chmod -R
• REMOVED
  • Keep Track of Changes Made to a File's Group with chgrp chgrp -v, chgrp -c

8 Archiving and Compression

• Archive and Compress Files Using zip zip
• Get the Best Compression Possible with zip zip -[0-9]
• Archive and Compress Files of a Specified Type in Directories and Subdirectories zip -r test.zip . -i \*.htm
• Password-Protect Compressed Zip Archives zip -P -e
• Unzip Files unzip
• Test Files That Will Be Unzipped unzip -t
• Archive and Compress Files Using gzip gzip
• Archive and Compress Files Recursively Using gzip gzip -r
• Uncompress Files Compressed with gzip gunzip
• Test Files That Will Be Unzipped with gunzip gzip -t
• Archive and Compress Files Using bzip2 bzip2
• Uncompress Files Compressed with bzip2 bunzip2
• Test Files That Will Be Unzipped with bunzip bunzip2 -t
• Archive Files with tar tar -cf
• Archive and Compress Files with tar and gzip tar -zcvf
• Test Files That Will Be Untarred and Uncompressed tar -zvft
• Untar and Uncompress Files tar -zxvf
• REMOVED
  • List Files That Will Be Unzipped unzip -l
  • Get the Best Compression Possible with gzip gzip -[0-9]
  • Get the Best Compression Possible with bzip2 bzip -[0-9]

9 Finding Files, Directories, Words, & Phrases

• Search a Database of Filenames locate
• Search a Database of Filenames Without Worrying About Case locate -i
• Update the Database Used by locate updatedb
• Searching Inside Text Files for Patterns grep
• The Basics of Searching Inside Text Files for Patterns
• Search Recursively for Text in Files grep -R
• Search for Words and Highlight the Results grep --color=auto
• Search for Text in Files, Ignoring Case grep -i
• Search for Whole Words Only in Files grep -w
• Show Line Numbers Where Words Appear in Files grep -n
• Search the Output of Other Commands for Specific Words
• See Context for Words Appearing in Files grep -A, -B, -C
• Show Lines Where Words Do Not Appear in Files grep -v
• List Files Containing Searched-for Words grep -l
• List the Number of Occurrences of Words in Files grep -c
• Search for Words Inside Search Results grep | grep
• REMOVED
  • Manage Results Received When Searching a Database of Filenames locate -n

10 The find Command

• Find Files by Name find -name
• Find Files by Ownership find -user & find -group
• Find Files by File Size find -size
• Find Files by File Type find -type
• Find Files by Modification Time find -mtime
• Show Results If the Expressions Are True (AND) find -a
• Show Results If Either Expression Is True (OR) find -o
• Show Results If the Expression Is Not True (NOT) find -n
• Execute a Command on Every Found File find -exec
• Execute a Command on Found Files More Efficiently find + & find | xargs
• Execute a Command on Found Files Containing Spaces find -print0
• REMOVED
  • Find Files by Group Ownership find -group
  • Print Find Results into a File find -fprint

11 Your Shell

• View Your Command-Line History history
• Run the Last Command Again !!
• Run a Previous Command Using Numbers ![##]
• Run a Previous Command Using a String ![string]
• Search for a Previous Command and Run It ^-r
• Display All Command Aliases alias
• View a Specific Command Alias alias [alias name]
• Create a New Temporary Alias alias [alias]='[command]'
• Create a New Permanent Alias alias [alias name]='[command]'
• Remove an Alias unalias
• Create a New Temporary Function [function name] () or function [function name]
• Create a New Permanent Function [function name] () or function [function name]
• Display All Functions
• Remove a Function unset -f [function name]
• When to Use an Alias and When to Use a Function

12 Monitoring System Resources

• Discover How Long Since Your Computer Was Restarted uptime
• View All Currently Running Processes ps aux
  • Also ps -w aux
• View a Process Tree ps axjf
• View Processes Owned by a Particular User ps U [username]
• End a Running Process kill
• End Every Instance of a Running Process killall
• View a Dynamically Updated List of Running Processes top
• List Open Files lsof
• List a User's Open Files lsof -u
• List Users for a Particular File lsof [file]
• List Processes for a Particular Program lsof -c [program]
• Display Information About System RAM free
• Show File System Disk Usage df
• Report File Space Used by a Directory du
• Report Just the Total Space Used for a Directory du -s
• Report File Space Used by a Directory and Its Files du -a
• Create a Sorted Report of File Space Used by a Directory du -k

13 Installing Software

• Install Software Packages for RPM-Based Distributions rpm -ihv, rpm -Uhv
• Remove Software Packages for RPM-Based Distributions rpm -e
• Install Software Packages and Dependencies for RPM-Based Distributions yum install
• Remove Software Packages and Dependencies for RPM-Based Distributions yum remove
• Upgrade Software Packages and Dependencies for RPM-Based Distributions yum update
• FIX: Find Packages Available for Download for RPM-Based Distributions yum search, yum list
• Install Software Packages for Debian-Based Distributions dpkg -i
• Remove Software Packages for Debian-Based Distributions dpkg -r
• Install Software Packages and Dependencies for Debian-Based Distributions apt-get install
• Remove Software Packages and Dependencies for Debian-Based Distributions apt-get remove
• Upgrade Software Packages and Dependencies for Debian-Based Distributions apt-get upgrade
• Find Packages Available for Download for Debian-Based Distributions apt-cache search
• Clean Up Unneeded Installation Packages for Debian-Based Distributions apt-get clean
• Troubleshoot Problems with apt

14 Connectivity

• View the Status of Your Network Interfaces ifconfig
• Show All Open Network Connections lsof -i
• Verify That a Computer Is Running and Accepting Requests ping, ping -c
  • Also ping -n
• Trace the Route Packets Take Between Two Hosts traceroute
  • Also traceroute -n
• Perform Simple DNS Lookups host
• Perform Complex DNS Lookups dig
• Configure a Network Interface ifconfig
• View the Status of Your Wireless Network Interfaces iwconfig
• Configure a Wireless Network Interface iwconfig
• Grab a New Address Using DHCP dhclient
• Make a Network Connection Active ifup
• Bring a Network Connection Down ifdown
• Display Your IP Routing Table route
  • Also route -n
• Change Your IP Routing Table route
• Troubleshooting Network Problems

15 Working on the Network

• Securely Log In to Another Computer ssh
• Securely Log In to Another Machine Without a Password ssh
• Securely and Conveniently Log In to Another Computer With a Password ssh-agent
• Emulate Several Terminals Within One, Even Disconnected screen (or tmux?)
• Securely Transfer Files Between Machines sftp
• Securely Copy Files Between Hosts scp
• Securely Transfer and Back Up Files rsync -avz
• Download Files Non-interactively wget
• Download Websites Non-interactively wget -r
• Download Sequential Files and Internet Resources curl
• Cruise the Web With a Text-Based Web Browser w3m, lynx, & elinks

16 Basic Shell Scripting

• Send Text to STDOUT echo
  • Also echo -e
• Print a Sequence of Numbers seq
• Comment Your Script #
• Run Commands If Conditions Are Met (Or Not) if then else
• Execute a Command For Every New Value In a List for
• Run Commands While Something Is True while
  • Also until
• Working With Variables date="date +%Y-%m-%d"
• Working With Functions
• Read User Input read
• Test If a Condition Is True Or False test & [
• Redirect Text Or Code To an Interactive Command (Here Document) <<