Learning Unix for OS X Mountain Lion: Using Unix and Linux Tools at the Command Line

235 Pages·2012·13.711 MB·English

by  Dave Taylo

Learning Unix for OS X
Mountain Lion
Dave Taylor
Learning Unix for OS X Mountain Lion
by Dave Taylor
Copyright © 2012 Dave Taylor. All rights reserved.
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October 2012: First Edition
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2012-09-19 First release
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ISBN: 978-1-449-33231-0
[LSI]
Table of Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
1. Why Use Unix?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The Power of Unix 1
Batch Renames and Extracting File Lists 4
Finding Hidden Files 5
Folders or Directories? 6
Thousands of Free Applications 7
Power Internet Connections 7
Commands Included with Unix 8
Displaying All Unix Commands 9
The 10 Most Common Unix Commands 9
A Simple Guided (Unix) Tour 10
2. Using the Terminal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Launching the Terminal 13
Syntax of a Unix Command 14
Exercise: Entering a Few Commands 16
Types of Commands 17
Changing the Terminal’s Preferences 18
Features of the Terminal 22
Customizing Your Terminal Session 23
Setting the Terminal’s Title 23
Using AppleScript to Manipulate the Terminal 24
Working with .terminal Files 25
Working with the Terminal 25
The Shell Prompt 27
Entering a Command 27
Recalling Previous Commands 28
Completing File and Directory Names 29
iii
Running Multiple Commands on the Command Line 30
Correcting a Command 30
Ending Your Session 31
Problem Checklist 31
Customizing the Shell Environment 32
Picking a Login Shell 32
Changing the Command Prompt 33
Advanced Shell Customization 35
Shell Configuration Settings 35
Creating Aliases 38
The Unresponsive Terminal 39
3. Exploring the Filesystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
The OS X Filesystem 41
Your Home Directory 42
Your Working Directory 42
The Directory Tree 43
Absolute Pathnames 44
Relative Pathnames 45
Changing Your Working Directory 47
Files in the Directory Tree 49
Listing Files and Directories 51
The All-Powerful ls Command 51
Trying Out the ls Command 52
Using the -l Option 55
File Permissions 56
Calculating File Size and Disk Space 59
Calculating Available Disk Space 62
Exercise: Exploring the Filesystem 63
Protecting and Sharing Files 64
File Access Permissions 66
Setting Permissions with chmod 67
Changing the Group and Owner 70
Changing Your Password 71
Superuser Privileges with sudo 72
Exploring External Volumes 74
4. File Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
File and Directory Names 77
File and Directory Wildcards 80
Looking Inside Files 82
cat 82
iv | Table of Contents
less 83
grep 85
Creating and Editing Files 86
Text Editors and Word Processors 87
The vi Text Editor 89
vi Basics 90
A Simpler vi Alternative: Pico 96
The More Complex Option: Emacs 97
Managing Files 98
Creating Directories with mkdir 99
Copying Files 100
Renaming and Moving Files with mv 102
Removing Files and Directories 103
Working with Links 105
Compressing and Archiving Files 107
Files on Other Operating Systems 110
5. Finding Files and Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
The Oddly Named grep Command 111
Useful grep Options 112
Working with Regular Expressions 114
Finding Files with locate 118
Building the locate Database 118
Using locate 119
Using find to Explore Your Filesystem 120
Matching by File Size 121
Exploring find Permission Strings 122
Using find to Identify Recently Changed Files 124
find’s Faithful Sidekick: xargs 125
Further Refinements to find 127
Shining a Light on Spotlight 128
Listing Spotlight Metadata with mdls 128
Finding Files with mdfind 132
Making Spotlight Useful 133
6. Redirecting I/O. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Standard Input and Standard Output 135
Putting Text in a File 137
Pipes and Filters 141
wc 142
tr 143
grep 144
Table of Contents | v
head and tail 145
sort 145
uniq 147
Piping Output to a Pager 147
Printing 149
The Unix Way 149
7. Multitasking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Running a Command in the Background 154
Checking on a Process 155
ps 155
top 157
Other Options for Monitoring Processes 160
Canceling a Process 162
kill 162
killall 163
Launching GUI Applications 164
open 165
Useful Starting Options for Use with open 166
Making open More Useful 167
8. Taking Unix Online. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Remote Logins 169
Web Access 173
Remote Access to Other Unix Systems 173
Transferring Files 176
scp and rcp 176
FTP 177
Easy Shortcuts with New Remote Connection 183
9. Of Windows and X11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
X11 186
Using X11 188
Differences Between OS X and X11 190
Customizing X11 191
GIMP, the X11 Graphics Editor 193
10. Where to Go from Here. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Documentation 195
The Terminal’s Help Menu 195
The man Command 196
Documentation on the Internet 199
vi | Table of Contents
Books 200
Customizing Your Unix Experience 200
Shell Aliases and Functions 200
Programming 201
Perl, Python, and Ruby 202
C and C++ 203
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
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