Unix Power Tools

by Powers, Shelley

• ISBN13: 9780596003302
• ISBN10: 0596003307
• Edition: 3rd
• Format: Paperback
• Copyright: 2002-10-01
• Publisher: Oreilly & Associates Inc

Summary

This new edition is loaded with even more advice about almost every aspect of Unix, covering new technologies that users need to know. In addition to vital information on Linux, Darwin and BSD, Unix Power Tools, 3rd Edition now offers more coverage of bash, zsh and other new shells, along with discussions on modern utilities and applications. Several sections focus on security and Internet access, acknowledging that most Unix boxes are connected to the Internet. And there is a new chapter on access to Unix from Windows, addressing the heterogeneous nature of systems today. Readers will also find expanded coverage of software installation and packaging, as well as basic information on Perl, Python, and Tcl.

Author Biography

is a long time user of the Unix operating system. He has acted as a Unix consultant, courseware developer, and instructor. He is one of the originating authors of Unix Power Tools and the author of Learning the Unix Operating System by O'Reilly.

Shelley Powers is an independent contractor, currently living in St. Louis, who specializes in technology architecture and software development. She's authored several computer books, including Developing ASP Components, Unix Power Tools 3rd edition, Essential Blogging, and Practical RDF. In addition, Shelley has also written several articles related primarily to web technology, many for O'Reilly. Shelley's web site network is at http://burningbird.net, and her weblog is Burningbird, at http://weblog.burningbird.net.

Table of Contents

How to Use This Book	xxvii
Preface	xxix
Part I Basic Unix Environment
Introduction	3	(29)
What's Special About Unix?	3	(1)
Power Grows on You	4	(2)
The Core of Unix	6	(1)
Communication with Unix	6	(2)
Programs Are Designed to Work Together	8	(1)
There Are Many Shells	9	(2)
Which Shell Am I Running?	11	(1)
Anyone Can Program the Shell	11	(2)
Internal and External Commands	13	(1)
The Kernel and Daemons	14	(2)
Filenames	16	(1)
Filename Extensions	17	(1)
Wildcards	18	(2)
The Tree Structure of the Filesystem	20	(2)
Your Home Directory	22	(1)
Making Pathnames	23	(2)
File Access Permissions	25	(1)
The Superuser (Root)	26	(1)
When Is a File Not a File?	27	(1)
Scripting	27	(1)
Unix Networking and Communications	28	(2)
The X Window System	30	(2)
Getting Help	32	(11)
The man Command	32	(1)
whatis: One-Line Command Summaries	33	(1)
whereis: Finding Where a Command Is Located	33	(1)
Searching Online Manual Pages	34	(2)
How Unix Systems Remember Their Names	36	(1)
Which Version Am I Using?	36	(1)
What tty Am I On?	37	(1)
Who's On?	38	(1)
The info Command	38	(5)
Part II Customizing Your Environment
Setting Up Your Unix Shell	43	(27)
What Happens When You Log In	43	(1)
The Mac OS X Terminal Application	44	(1)
Shell Setup Files---Which, Where, and Why	44	(4)
Login Shells, Interactive Shells	48	(1)
What Goes in Shell Setup Files?	49	(1)
Tip for Changing Account Setup: Keep a Shell Ready	50	(1)
Use Absolute Pathnames in Shell Setup Files	51	(1)
Setup Files Aren't Read When You Want?	51	(2)
Gotchas in set prompt Test	53	(1)
Automatic Setups for Different Terminals	54	(1)
Terminal Setup: Testing TERM	55	(1)
Terminal Setup: Testing Remote Hostname and X Display	56	(1)
Terminal Setup: Testing Port	57	(1)
Terminal Setup: Testing Environment Variables	57	(1)
Terminal Setup: Searching Terminal Table	58	(1)
Terminal Setup: Testing Window Size	58	(1)
Terminal Setup: Setting and Testing Window Name	59	(1)
A .cshrc.$HOST File for Per Host Setup	60	(1)
Making a ``Login'' Shell	61	(1)
RC Files	62	(3)
Make Your Own Manpages Without Learning troff	65	(2)
Writing a Simple Manpage with the --man Macros	67	(3)
Interacting with Your Environment	70	(22)
Basics of Setting the Prompt	70	(1)
Static Prompts	70	(1)
Dynamic Prompts	71	(1)
Simulating Dynamic Prompts	72	(1)
C-Shell Prompt Causes Problems in vi, rsh, etc.	73	(1)
Faster Prompt Setting with Built-ins	74	(2)
Multiline Shell Prompts	76	(1)
Session Info in Window Title or Status Line	77	(2)
A ``Menu Prompt'' for Naive Users	79	(1)
Highlighting and Color in Shell Prompts	79	(2)
Right-Side Prompts	81	(1)
Show Subshell Level with $SHLVL	82	(1)
What Good Is a Blank Shell Prompt?	83	(1)
dirs in Your Prompt: Better Than $cwd	84	(2)
External Commands Send Signals to Set Variables	86	(1)
Preprompt, Pre-execution, and Periodic Commands	87	(2)
Running Commands When You Log Out	89	(1)
Running Commands at Bourne/Korn Shell Logout	90	(1)
Stop Accidental Bourne-Shell Logouts	90	(2)
Getting the Most out of Terminals, xterm, and X Windows	92	(32)
There's a Lot to Know About Terminals	92	(1)
The Idea of a Terminal Database	93	(2)
Setting the Terminal Type When You Log In	95	(2)
Querying Your Terminal Type: qterm	97	(2)
Querying Your xterm Size: resize	99	(1)
Checklist: Terminal Hangs When I Log In	100	(4)
Find Out Terminal Settings with stty	104	(1)
Setting Your Erase, Kill, and Interrupt Characters	104	(2)
Working with xterm and Friends	106	(1)
Login xterms and rxvts	107	(1)
Working with Scrollbars	108	(1)
How Many Lines to Save?	109	(1)
Simple Copy and Paste in xterm	109	(1)
Defining What Makes Up a Word for Selection Purposes	110	(1)
Setting the Titlebar and Icon Text	111	(1)
The Simple Way to Pick a Font	112	(1)
The xterm Menus	113	(2)
Changing Fonts Dynamically	115	(2)
Working with xclipboard	117	(2)
Problems with Large Selections	119	(1)
Tips for Copy and Paste Between Windows	120	(2)
Running a Single Command with xterm --e	122	(1)
Don't Quote Arguments to xterm --e	123	(1)
Your X Environment	124	(23)
Defining Keys and Button Presses with xmodmap	124	(3)
Using xev to Learn Keysym Mappings	127	(1)
X Resource Syntax	128	(2)
X Event Translations	130	(3)
Setting X Resources: Overview	133	(2)
Setting Resources with the --xrm Option	135	(1)
How --name Affects Resources	135	(1)
Setting Resources with xrdb	136	(3)
Listing the Current Resources for a Client: appres	139	(1)
Starting Remote X Clients	140	(7)
Part III Working with Files and Directories
Directory Organization	147	(7)
What? Me, Organized?	147	(1)
Many Homes	148	(1)
Access to Directories	148	(1)
A bin Directory for Your Programs and Scripts	149	(1)
Private (Personal) Directories	150	(1)
Naming Files	150	(1)
Make More Directories!	151	(1)
Making Directories Made Easier	152	(2)
Directories and Files	154	(17)
Everything but the find Command	154	(1)
The Three Unix File Times	154	(1)
Finding Oldest or Newest Files with ls --t and ls --u	155	(2)
List All Subdirectories with ls --R	157	(1)
The ls --d Option	157	(1)
Color Is	158	(3)
Some GNU Is Features	161	(1)
A csh Alias to List Recently Changed Files	162	(1)
Showing Hidden Files with ls --A and --a	163	(1)
Useful Is Aliases	163	(2)
Can't Access a File? Look for Spaces in the Name	165	(1)
Showing Nonprintable Characters in Filenames	166	(1)
Counting Files by Types	167	(1)
Listing Files by Age and Size	168	(1)
newer: Print the Name of the Newest File	169	(1)
oldlinks: Find Unconnected Symbolic Links	169	(1)
Picking a Unique Filename Automatically	170	(1)
Finding Files with find	171	(30)
How to Use find	171	(2)
Delving Through a Deep Directory Tree	173	(2)
Don't Forget --print	175	(1)
Looking for Files with Particular Names	175	(1)
Searching for Old Files	175	(1)
Be an Expert on find Search Operators	176	(2)
The Times That find Finds	178	(1)
Exact File-Time Comparisons	179	(1)
Running Commands on What You Find	179	(2)
Using --exec to Create Custom Tests	181	(1)
Custom --exec Tests Applied	182	(1)
Finding Many Things with One Command	182	(2)
Searching for Files by Type	184	(1)
Searching for Files by Size	185	(1)
Searching for Files by Permission	185	(1)
Searching by Owner and Group	186	(1)
Duplicating a Directory Tree	187	(1)
Using ``Fast find'' Databases	187	(2)
Wildcards with ``Fast find'' Database	189	(1)
Finding Files (Much) Faster with a find Database	190	(2)
grepping a Directory Tree	192	(1)
lookfor: Which File Has That Word?	193	(1)
Using Shell Arrays to Browse Directories	194	(3)
Finding the (Hard) Links to a File	197	(1)
Finding Files with --prune	198	(1)
Quick finds in the Current Directory	199	(1)
Skipping Parts of a Tree in find	199	(1)
Keeping find from Searching Networked Filesystem	200	(1)
Linking, Renaming, and Copying Files	201	(17)
What's So Complicated About Copying Files	201	(1)
What's Really in a Directory?	201	(2)
Files with Two or More Names	203	(2)
More About Links	205	(3)
Creating and Removing Links	208	(1)
Stale Symbolic Links	209	(1)
Linking Directories	210	(2)
Showing the Actual Filenames for Symbolic Links	212	(1)
Renaming, Copying, or Comparing a Set of Files	212	(1)
Renaming a List of Files Interactively	213	(1)
One More Way to Do It	213	(1)
Copying Directory Trees with cp --r	214	(2)
Copying Directory Trees with tar and Pipes	216	(2)
Comparing Files	218	(16)
Checking Differences with diff	218	(2)
Comparing Three Different Versions with diff3	220	(1)
Context diffs	221	(3)
Side-by-Side diffs: sdiff	224	(1)
Choosing Sides with sdiff	225	(1)
Problems with diff and Tabstops	225	(1)
cmp and diff	226	(1)
Comparing Two Files with comm	227	(2)
More Friendly comm Output	229	(1)
make Isn't Just for Programmers!	230	(2)
Even More Uses for make	232	(2)
Showing What's in a File	234	(13)
Cracking the Nut	234	(1)
What Good Is a cat?	234	(2)
``less'' is More	236	(1)
Show Nonprinting Characters with cat --v or od --c	237	(2)
What's in That Whitespace?	239	(1)
Finding File Types	240	(1)
Squash Extra Blank Lines	241	(1)
How to Look at the End of a File: tail	242	(1)
Finer Control on tail	243	(1)
How to Look at Files as They Grow	243	(2)
GNU tail File Following	245	(1)
Printing the Top of a File	246	(1)
Numbering Lines	246	(1)
Searching Through Files	247	(15)
Different Versions of grep	247	(1)
Searching for Text with grep	248	(1)
Finding Text That Doesn't Match	249	(1)
Extended Searching for Text with egrep	250	(1)
grepping for a List of Patterns	251	(1)
Approximate grep: agrep	251	(1)
Search RCS Files with rcsgrep	252	(2)
GNU Context greps	254	(1)
A Multiline Context grep Using sed	255	(1)
Compound Searches	256	(1)
Narrowing a Search Quickly	257	(1)
Faking Case-Insensitive Searches	258	(1)
Finding a Character in a Column	258	(1)
Fast Searches and Spelling Checks with ``look''	259	(1)
Finding Words Inside Binary Files	259	(1)
A Highlighting grep	260	(2)
Removing Files	262	(15)
The Cycle of Creation and Destruction	262	(1)
How Unix Keeps Track of Files: Inodes	262	(1)
rm and Its Dangers	263	(2)
Tricks for Making rm Safer	265	(1)
Answer ``Yes'' or ``No'' Forever with yes	265	(1)
Remove Some, Leave Some	266	(1)
A Faster Way to Remove Files Interactively	266	(1)
Safer File Deletion in Some Directories	267	(1)
Safe Delete: Pros and Cons	268	(1)
Deletion with Prejudice: rm --f	269	(1)
Deleting Files with Odd Names	269	(1)
Using Wildcards to Delete Files with Strange Names	270	(1)
Handling a Filename Starting with a Dash (--)	271	(1)
Using unlink to Remove a File with a Strange Name	271	(1)
Removing a Strange File by its i-number	272	(1)
Problems Deleting Directories	272	(2)
Deleting Stale Files	274	(1)
Removing Every File but One	275	(1)
Using find to Clear Out Unneeded Files	276	(1)
Optimizing Disk Space	277	(18)
Disk Space Is Cheap	277	(1)
Instead of Removing a File, Empty It	277	(2)
Save Space with ``Bit Bucket'' Log Files and Mailboxes	279	(1)
Save Space with a Link	279	(1)
Limiting File Sizes	280	(1)
Compressing Files to Save Space	281	(3)
Save Space: tar and compress a Directory Tree	284	(2)
How Much Disk Space?	286	(2)
Compressing a Directory Tree: Fine-Tuning	288	(1)
Save Space in Executable Files with strip	289	(1)
Disk Quotas	290	(5)
Part IV Basic Editing
Spell Checking, Word Counting, and Textual Analysis	295	(13)
The Unix spell Command	295	(1)
Check Spelling Interactively with ispell	296	(2)
How Do I Spell That Word?	298	(1)
Inside spell	299	(2)
Adding Words to ispell's Dictionary	301	(2)
Counting Lines, Words, and Characters: wc	303	(2)
Find a a Doubled Word	305	(1)
Looking for Closure	305	(1)
Just the Words, Please	306	(2)
vi Tips and Tricks	308	(28)
The vi Editor: Why So Much Material?	308	(1)
What We Cover	309	(1)
Editing Multiple Files with vi	309	(2)
Edits Between Files	311	(1)
Local Settings for vi	312	(1)
Using Buffers to Move or Copy Text	313	(1)
Get Back What You Deleted with Numbered Buffers	313	(1)
Using Search Patterns and Global Commands	314	(1)
Confirming Substitutions in vi	315	(1)
Keep Your Original File, Write to a New File	316	(1)
Saving Part of a File	316	(1)
Appending to an Existing File	317	(1)
Moving Blocks of Text by Patterns	317	(1)
Useful Global Commands (with Pattern Matches)	318	(2)
Counting Occurrences; Stopping Search Wraps	320	(1)
Capitalizing Every Word on a Line	320	(1)
Per-File Setups in Separate Files	321	(1)
Filtering Text Through a Unix Command	322	(2)
vi File Recovery Versus Networked Filesystems	324	(1)
Be Careful with vi --r Recovered Buffers	325	(1)
Shell Escapes: Running One Unix Command While Using Another	326	(1)
vi Compound Searches	327	(1)
vi Word Abbreviation	328	(2)
Using vi Abbreviations as Commands (Cut and Paste Between vi's)	330	(1)
Fixing Typos with vi Abbreviations	330	(1)
vi Line Commands Versus Character Commands	331	(1)
Out of Temporary Space? Use Another Directory	332	(1)
Neatening Lines	333	(1)
Finding Your Place with Undo	334	(1)
Setting Up vi with the .exrc File	334	(2)
Creating Custom Commands in vi	336	(17)
Why Type More Than You Have To?	336	(1)
Save Time and Typing with the vi map Commands	336	(3)
What You Lose When You Use map!	339	(1)
vi @-Functions	340	(3)
Keymaps for Pasting into a Window Running vi	343	(1)
Protecting Keys from Interpretation by ex	343	(2)
Maps for Repeated Edits	345	(2)
More Examples of Mapping Keys in vi	347	(1)
Repeating a vi Keymap	348	(1)
Typing in Uppercase Without CAPS LOCK	348	(1)
Text-Input Mode Cursor Motion with No Arrow Keys	349	(1)
Don't Lose Important Functions with vi Maps: Use noremap	350	(1)
vi Macro for Splitting Long Lines	350	(1)
File-Backup Macros	351	(2)
GNU Emacs	353	(14)
Emacs: The Other Editor	353	(1)
Emacs Features: A Laundry List	354	(4)
Customizations and How to Avoid Them	358	(1)
Backup and Auto-Save Files	358	(2)
Putting Emacs in Overwrite Mode	360	(1)
Command Completion	360	(1)
Mike's Favorite Timesavers	361	(1)
Rational Searches	362	(1)
Unset PWD Before Using Emacs	363	(1)
Inserting Binary Characters into Files	363	(1)
Using Word-Abbreviation Mode	364	(2)
Directories for Emacs Hacks	366	(1)
An Absurd Amusement	366	(1)
Batch Editing	367	(23)
Why Line Editors Aren't Dinosaurs	367	(1)
Writing Editing Scripts	368	(1)
Line Addressing	369	(1)
Useful ex Commands	370	(3)
Running Editing Scripts Within vi	373	(1)
Change Many Files by Editing Just One	373	(2)
ed/ex Batch Edits: A Typical Example	375	(1)
Batch Editing Gotcha: Editors Fail on Big Files	376	(1)
patch: Generalized Updating of Files That Differ	377	(1)
Quick Reference: awk	378	(10)
Versions of awk	388	(2)
You Can't Quite Call This Editing	390	(31)
And Why Not?	390	(1)
Neatening Text with fmt	391	(1)
Alternatives to fmt	392	(2)
Clean Up Program Comment Blocks	394	(1)
Remove Mail/News Headers with behead	395	(1)
Low-Level File Butchery with dd	396	(1)
offset: Indent Text	396	(1)
Centering Lines in a File	397	(1)
Splitting Files at Fixed Points: split	398	(3)
Splitting Files by Context: csplit	401	(3)
Hacking on Characters with tr	404	(2)
Encoding ``Binary'' Files into ASCII	406	(4)
Text Conversion with dd	410	(1)
Cutting Columns or Fields	410	(1)
Making Text in Columns with pr	411	(2)
Make Columns Automatically with column	413	(2)
Straightening Jagged Columns	415	(1)
Pasting Things in Columns	416	(1)
Joining Lines with join	417	(1)
What Is (or Isn't) Unique?	418	(1)
Rotating Text	419	(2)
Sorting	421	(14)
Putting Things in Order	421	(1)
Sort Fields: How sort Sorts	422	(2)
Changing the sort Field Delimiter	424	(1)
Confusion with Whitespace Field Delimiters	424	(2)
Alphabetic and Numeric Sorting	426	(1)
Miscellaneous sort Hints	427	(2)
Iensort: Sort Lines by Length	429	(1)
Sorting a List of People by Last Name	430	(5)
Part V Processes and the Kernel
Job Control	435	(16)
Job Control in a Nutshell	435	(2)
Job Control Basics	437	(1)
Using jobs Effectively	438	(2)
Some Gotchas with Job Control	440	(2)
The ``Current Job'' Isn't Always What You Expect	442	(1)
Job Control and autowrite: Real Timesavers!	442	(1)
System Overloaded? Try Stopping Some Jobs	443	(1)
Notification When Jobs Change State	444	(1)
Stop Background Output with stty tostop	444	(1)
nohup	445	(1)
Disowning Processes	446	(1)
Linux Virtual Consoles	447	(2)
Stopping Remote Login Sessions	449	(2)
Starting, Stopping, and Killing Processes	451	(37)
What's in This Chapter	451	(1)
fork and exec	452	(1)
Managing Processes: Overall Concepts	453	(2)
Subshells	455	(1)
The ps Command	456	(3)
The Controlling Terminal	459	(1)
Tracking Down Processes	460	(2)
Why ps Prints Some Commands in Parentheses	462	(1)
The /proc Filesystem	463	(5)
What Are Signals?	468	(1)
Killing Foreground Jobs	469	(1)
Destroying Processes with kill	470	(1)
Printer Queue Watcher: A Restartable Daemon Shell Script	471	(2)
Killing All Your Processes	473	(1)
Killing Processes by Name?	474	(2)
Kill Processes Interactively	476	(2)
Processes Out of Control? Just STOP Them	478	(1)
Cleaning Up an Unkillable Process	479	(1)
Why You Can't Kill a Zombie	480	(1)
The Process Chain to Your Window	480	(2)
Terminal Windows Without Shells	482	(2)
Close a Window by Killing Its Process(es)	484	(4)
Delayed Execution	488	(12)
Building Software Robots the Easy Way	488	(1)
Periodic Program Execution: The cron Facility	489	(5)
Adding crontab Entries	494	(1)
Including Standard Input Within a cron Entry	495	(1)
The at Command	495	(1)
Making Your at Jobs Quiet	496	(1)
Checking and Removing Jobs	496	(1)
Avoiding Other at and cron Jobs	497	(1)
Waiting a Little While: sleep	498	(2)
System Performance and Profiling	500	(13)
Timing Is Everything	500	(3)
Timing Programs	503	(1)
What Commands Are Running and How Long Do They Take?	504	(2)
Checking System Load: uptime	506	(1)
Know When to Be ``nice'' to Other Users...and When Not To	506	(4)
A nice Gotcha	510	(1)
Changing a Running Job's Niceness	510	(3)
Part VI Scripting
Shell Interpretation	513	(29)
What the Shell Does	513	(1)
How the Shell Executes Other Commands	514	(1)
What's a Shell, Anyway?	515	(2)
Command Evaluation and Accidentally Overwriting Files	517	(1)
Output Command-Line Arguments One by One	518	(1)
Controlling Shell Command Searches	518	(2)
Wildcards Inside Aliases	520	(1)
eval: When You Need Another Chance	521	(2)
Which One Will bash Use?	523	(1)
Which One Will the C Shell Use?	524	(2)
Is It ``2>&1 file'' or ``>file2>&1''? Why?	526	(1)
Bourne Shell Quoting	526	(5)
Differences Between Bourne and C Shell Quoting	531	(2)
Quoting Special Characters in Filenames	533	(1)
Verbose and Echo Settings Show Quoting	533	(1)
Here Documents	534	(1)
``Special'' Characters and Operators	535	(5)
How Many Backslashes?	540	(2)
Saving Time on the Command Line	542	(29)
What's Special About the Unix Command Line	542	(1)
Reprinting Your Command Line with CTRL-r	543	(1)
Use Wildcards to Create Files?	544	(1)
Build Strings with { }	545	(2)
String Editing (Colon) Operators	547	(2)
Automatic Completion	549	(4)
Don't Match Useless Files in Filename Completion	553	(1)
Repeating Commands	554	(1)
Repeating and Varying Commands	554	(3)
Repeating a Command with Copy-and-Paste	557	(1)
Repeating a Time-Varying Command	558	(1)
Multiline Commands, Secondary Prompts	559	(1)
Here Document Example #1: Unformatted Form Letters	560	(1)
Command Substitution	561	(2)
Handling Lots of Text with Temporary Files	563	(1)
Separating Commands with Semicolons	563	(2)
Dealing with Too Many Arguments	565	(2)
Expect	567	(4)
Custom Commands	571	(22)
Creating Custom Commands	571	(1)
Introduction to Shell Aliases	571	(1)
C-Shell Aliases with Command-Line Arguments	572	(2)
Setting and Unsetting Bourne-Type Aliases	574	(1)
Korn-Shell Aliases	575	(1)
zsh Aliases	576	(1)
Sourceable Scripts	576	(2)
Avoiding C-Shell Alias Loops	578	(1)
How to Put if-then-else in a C-Shell Alias	579	(1)
Fix Quoting in csh Aliases with makealias and quote	580	(1)
Shell Function Basics	581	(4)
Shell Function Specifics	585	(1)
Propagating Shell Functions	586	(5)
Simulated Bourne Shell Functions and Aliases	591	(2)
The Use of History	593	(24)
The Lessons of History	593	(1)
History in a Nutshell	594	(1)
My Favorite Is !$	595	(1)
My Favorite Is !:n*	595	(1)
My Favorite Is ^^	596	(1)
Using !$ for Safety with Wildcards	597	(1)
History by Number	597	(2)
History Substitutions	599	(5)
Repeating a Cycle of Commands	604	(1)
Running a Series of Commands on a File	604	(1)
Check Your History First with :p	605	(1)
Picking Up Where You Left Off	606	(2)
Pass History to Another Shell	608	(1)
Shell Command-Line Editing	609	(6)
Changing History Characters with histchars	615	(1)
Instead of Changing History Characters	616	(1)
Moving Around in a Hurry	617	(16)
Getting Around the Filesystem	617	(1)
Using Relative and Absolute Pathnames	618	(2)
What Good Is a Current Directory?	620	(1)
How Does Unix Find Your Current Directory?	621	(1)
Saving Time When You Change Directories: cdpath	622	(1)
Loop Control: break and Continue	623	(1)
The Shells' pushd and popd Commands	624	(2)
Nice Aliases for pushd	626	(1)
Quick cds with Aliases	627	(1)
cd by Directory Initials	627	(2)
Finding (Anyone's) Home Directory, Quickly	629	(1)
Marking Your Place with a Shell Variable	630	(1)
Automatic Setup When You Enter/Exit a Directory	630	(3)
Regular Expressions (Pattern Matching)	633	(24)
That's an Expression	633	(1)
Don't Confuse Regular Expressions with Wildcards	634	(1)
Understanding Expressions	635	(2)
Using Metacharacters in Regular Expressions	637	(1)
Regular Expressions: The Anchor Characters ^ and $	638	(1)
Regular Expressions: Matching a Character with a Character Set	639	(1)
Regular Expressions: Match Any Character with . (Dot)	640	(1)
Regular Expressions: Specifying a Range of Characters with [...]	640	(1)
Regular Expressions: Exceptions in a Character Set	641	(1)
Regular Expressions: Repeating Character Sets with *	641	(1)
Regular Expressions: Matching a Specific Number of Sets with \ { and \ }	642	(1)
Regular Expressions: Matching Words with \ < and \ >	643	(1)
Regular Expressions: Remembering Patterns with \ (, \), and \1	644	(1)
Regular Expressions: Potential Problems	644	(1)
Extended Regular Expressions	645	(1)
Getting Regular Expressions Right	646	(2)
Just What Does a Regular Expression Match?	648	(1)
Limiting the Extent of a Match	649	(1)
I Never Meta Character I Didn't Like	650	(1)
Valid Metacharacters for Different Unix Programs	651	(1)
Pattern Matching Quick Reference with Examples	652	(5)
Wildcards	657	(11)
File-Naming Wildcards	657	(1)
Filename Wildcards in a Nutshell	658	(2)
Who Handles Wildcards?	660	(2)
What if a Wildcard Doesn't Match?	662	(1)
Maybe You Shouldn't Use Wildcards in Pathnames	663	(1)
Getting a List of Matching Files with grep --1	664	(1)
Getting a List of Nonmatching Files	664	(2)
nom: List Files That Don't Match a Wildcard	666	(2)
The sed Stream Editor	668	(30)
sed Sermon^H^H^H^H^H^HSummary	668	(1)
Two Things You Must Know About sed	669	(1)
Invoking sed	669	(1)
Testing and Using a sed Script: checksed, runsed	670	(2)
sed Addressing Basics	672	(2)
Order of Commands in a Script	674	(1)
One Thing at a Time	675	(1)
Delimiting a Regular Expression	675	(1)
Newlines in a sed Replacement	676	(1)
Referencing the Search String in a Replacement	677	(1)
Referencing Portions of a Search String	678	(1)
Search and Replacement: One Match Among Many	679	(1)
Transformations on Text	680	(1)
Hold Space: The Set-Aside Buffer	680	(3)
Transforming Part of a Line	683	(2)
Making Edits Across Line Boundaries	685	(3)
The Deliberate Scrivener	688	(2)
Searching for Patterns Split Across Lines	690	(2)
Multiline Delete	692	(1)
Making Edits Everywhere Except...	693	(2)
The sed Test Command	695	(1)
Uses of the sed Quit Command	696	(1)
Dangers of the sed Quit Command	696	(1)
sed Newlines, Quoting, and Backslashes in a Shell Script	697	(1)
Shell Programming for the Uninitiated	698	(43)
Writing a Simple Shell Program	698	(2)
Everyone Should Learn Some Shell Programming	700	(2)
What Environment Variables Are Good For	702	(3)
Parent-Child Relationships	705	(1)
Predefined Environment Variables	705	(3)
The PATH Environment Variable	708	(1)
PATH and path	709	(1)
The DISPLAY Environment Variable	710	(1)
Shell Variables	711	(2)
Test String Values with Bourne-Shell case	713	(1)
Pattern Matching in case Statements	714	(1)
Exit Status of Unix Processes	715	(1)
Test Exit Status with the if Statement	716	(2)
Testing Your Success	718	(1)
Loops That Test Exit Status	719	(1)
Set Exit Status of a Shell (Script)	720	(1)
Trapping Exits Caused by Interrupts	721	(2)
read: Reading from the Keyboard	723	(1)
Shell Script ``Wrappers'' for awk, sed, etc.	724	(1)
Handling Command-Line Arguments in Shell Scripts	725	(2)
Handling Command-Line Arguments with a for Loop	727	(1)
Handling Arguments with while and shift	728	(2)
Loop Control: break and continue	730	(1)
Standard Command-Line Parsing	730	(2)
The Bourne Shell set Command	732	(3)
test: Testing Files and Strings	735	(1)
Picking a Name for a New Command	736	(1)
Finding a Program Name and Giving Your Program Multiple Names	736	(1)
Reading Files with the . and source Commands	737	(1)
Using Shell Functions in Shell Scripts	738	(3)
Shell Programming for the Initiated	741	(34)
Beyond the Basics	741	(1)
The Story of : # #!	742	(1)
Don't Need a Shell for Your Script? Don't Use One	743	(1)
Making #! Search the PATH	744	(1)
The exec Command	745	(1)
The Unappreciated Bourne Shell ``:'' Operator	746	(1)
Parameter Substitution	747	(1)
Save Disk Space and Programming: Multiple Names for a Program	748	(1)
Finding the Last Command-Line Argument	749	(1)
How to Unset All Command-Line Parameters	749	(1)
Standard Input to a for Loop	750	(1)
Making a for Loop with Multiple Variables	750	(1)
Using basename and dirname	751	(2)
A while Loop with Several Loop Control Commands	753	(1)
Overview: Open Files and File Descriptors	753	(3)
n>&m: Swap Standard Output and Standard Error	756	(3)
A Shell Can Read a Script from Its Standard Input, but...	759	(1)
Shell Scripts On-the-Fly from Standard Input	760	(1)
Quoted hereis Document Terminators: sh Versus csh	761	(1)
Turn Off echo for ``Secret'' Answers	761	(1)
Quick Reference: expr	762	(2)
Testing Characters in a String with expr	764	(1)
Grabbing Parts of a String	764	(4)
Nested Command Substitution	768	(2)
Testing Two Strings with One case Statement	770	(1)
Outputting Text to an X Window	770	(2)
Shell Lockfile	772	(3)
Shell Script Debugging and Gotchas	775	(12)
Tips for Debugging Shell Scripts	775	(2)
Bourne Shell Debugger Shows a Shell Variable	777	(1)
Stop Syntax Errors in Numeric Tests	777	(1)
Stop Syntax Errors in String Tests	778	(1)
Quoting and Command-Line Parameters	779	(2)
How Unix Keeps Time	781	(1)
Copy What You Do with script	782	(1)
Cleaning script Files	783	(1)
Making an Arbitrary-Size File for Testing	784	(3)
Part VII Extending and Managing Your Environment
Backing Up Files	787	(21)
What Is This ``Backup'' Thing?	787	(1)
tar in a Nutshell	788	(1)
Make Your Own Backups	788	(2)
More Ways to Back Up	790	(1)
How to Make Backups to a Local Device	790	(5)
Restoring Files from Tape with tar	795	(2)
Using tar to a Remote Tape Drive	797	(1)
Using GNU tar with a Remote Tape Drive	798	(1)
On-Demand Incremental Backups of a Project	798	(2)
Using Wildcards with tar	800	(3)
Avoid Absolute Paths with tar	803	(1)
Getting tar's Arguments in the Right Order	804	(1)
The cpio Tape Archiver	805	(1)
Industrial Strength Backups	806	(2)
Creating and Reading Archives	808	(14)
Packing Up and Moving	808	(1)
Using tar to Create and Unpack Archives	809	(4)
GNU tar Sampler	813	(1)
Managing and Sharing Files with RCS and CVS	814	(1)
RCS Basics	815	(2)
List RCS Revision Numbers with rcsrevs	817	(1)
CVS Basics	818	(1)
More CVS	819	(3)
Software Installation	822	(17)
/usr/bin and Other Software Directories	822	(2)
The Challenges of Software Installation on Unix	824	(1)
Which make?	824	(1)
Simplifying the make Process	824	(1)
Using Debian's dselect	825	(7)
Installing Software with Debian's Apt-Get	832	(2)
Interruptable gets with wget	834	(2)
The curl Application and One-Step GNU-Darwin Auto-Installer for OS X	836	(1)
Installation with FreeBSD Ports	837	(1)
Installing with FreeBSD Packages	837	(1)
Finding and Installing RPM Packaged Software	838	(1)
Perl	839	(30)
High-Octane Shell Scripting	839	(1)
Checking your Perl Installation	839	(2)
Compiling Perl from Scratch	841	(1)
Perl Boot Camp, Part 1: Typical Script Anatomy	842	(3)
Perl Boot Camp, Part 2: Variables and Data Types	845	(7)
Perl Boot Camp, Part 3: Branching and Looping	852	(2)
Perl Boot Camp, Part 4: Pattern Matching	854	(2)
Perl Boot Camp, Part 5: Perl Knows Unix	856	(3)
Perl Boot Camp, Part 6: Modules	859	(2)
Perl Boot Camp, Part 7: perldoc	861	(1)
CPAN	862	(3)
Make Custom grep Commands (etc.) with Perl	865	(1)
Perl and the Internet	866	(3)
Python	869	(16)
What Is Python?	869	(1)
Installation and Distutils	869	(2)
Python Basics	871	(5)
Python and the Web	876	(1)
urllib	876	(1)
urllib2	877	(1)
htmllib and HTMLParser	878	(1)
cgi	878	(1)
mod_Python	879	(1)
What About Perl?	880	(5)
Part VIII Communication and Connectivity
Redirecting Input and Output	885	(15)
Using Standard Input and Output	885	(3)
One Argument with a cat Isn't Enough	888	(1)
Send (Only) Standard Error Down a Pipe	888	(1)
Problems Piping to a Pager	889	(2)
Redirection in C Shell: Capture Errors, Too?	891	(1)
Safe I/O Redirection with noclobber	892	(1)
The () Subshell Operators	893	(1)
Send Output Two or More Places	894	(1)
How to tee Several Commands into One Place	895	(1)
Redirecting Output to More Than One Place	895	(2)
Named Pipes: FIFOs	897	(1)
What Can You Do with an Empty File?	898	(2)
Devices	900	(14)
Quick Introduction to Hardware	900	(1)
Reading Kernel Boot Output	900	(2)
Basic Kernel Configuration	902	(1)
Disk Partitioning	903	(1)
Filesystem Types and /etc/fstab	904	(2)
Mounting and Unmounting Removable Filesystems	906	(1)
Loopback Mounts	907	(1)
Network Devices---ifconfig	908	(1)
Mounting Network Filesystems---NFS, SMBFS	908	(1)
Win Is a Modem Not a Modem?	909	(1)
Setting Up a Dialup PPP Session	910	(1)
USB Configuration	911	(1)
Dealing with Sound Cards and Other Annoying Hardware	911	(1)
Decapitating Your Machine---Serial Consoles	912	(2)
Printing	914	(22)
Introduction to Printing	914	(1)
Introduction to Printing on Unix	915	(2)
Printer Control with lpc	917	(1)
Using Different Printers	918	(1)
Using Symbolic Links for Spooling	919	(1)
Formatting Plain Text: pr	920	(2)
Formatting Plain Text: enscript	922	(1)
Printing Over a Network	923	(1)
Printing Over Samba	923	(2)
Introduction to Typesetting	925	(1)
A Bit of Unix Typesetting History	926	(1)
Typesetting Manpages: nroff	927	(1)
Formatting Markup Languages---troff, LATEX, HTML, and So On	928	(1)
Printing Languages---PostScript, PCL, DVI, PDF	929	(1)
Converting Text Files into a Printing Language	930	(1)
Converting Typeset Files into a Printing Language	931	(1)
Converting Source Files Automagically Within the Spooler	932	(1)
The Common Unix Printing System (CUPS)	933	(1)
The Portable Bitmap Package	933	(3)
Connectivity	936	(15)
TCP/IP---IP Addresses and Ports	936	(2)
/etc/services Is Your Friend	938	(1)
Status and Troubleshooting	939	(2)
Where, Oh Where Did That Packet Go?	941	(1)
The Director of Operations: inetd	942	(1)
Secure Shell (SSH)	943	(1)
Configuring an Anonymous FTP Server	944	(1)
Mail---SMTP, POP, and IMAP	944	(1)
Domain Name Service (DNS)	945	(2)
Dynamic Host Configuration Protocol (DHCP)	947	(1)
Gateways and NAT	948	(1)
Firewalls	949	(1)
Gatewaying from a Personal LAN over a Modem	950	(1)
Connecting to MS Windows	951	(18)
Building Bridges	951	(1)
Installing and Configuring Samba	951	(4)
Securing Samba	955	(1)
SWAT and GUI SMB Browsers	956	(2)
Printing with Samba	958	(1)
Connecting to SMB Shares from Unix	959	(1)
Sharing Desktops with VNC	959	(3)
Of Emulators and APIs	962	(1)
Citrix: Making Windows Multiuser	963	(6)
Part IX Security
Security Basics	969	(13)
Understanding Points of Vulnerability	969	(1)
CERT Security Checklists	970	(1)
Keeping Up with Security Alerts	971	(1)
What We Mean by Buffer Overflow	972	(1)
What We Mean by DoS	973	(1)
Beware of Sluggish Performance	974	(3)
Intruder Detection	977	(1)
Importance of MOTD	978	(1)
The Linux proc Filesystem	979	(1)
Disabling inetd	979	(1)
Disallow rlogin and rsh	980	(1)
TCP Wrappers	980	(2)
Root, Group, and User Management	982	(12)
Unix User/Group Infrastructure	982	(1)
When Does a User Become a User	982	(2)
Forgetting the root Password	984	(1)
Setting an Exact umask	985	(1)
Group Permissions in a Directory with the setgid Bit	985	(1)
Groups and Group Ownership	986	(2)
Add Users to a Group to Deny Permissions	988	(1)
Care and Feeding of SUID and SGID Scripts	989	(1)
Substitute Identity with su	990	(1)
Never Log In as root	990	(1)
Providing Superpowers with sudo	991	(1)
Enabling Root in Darwin	992	(1)
Disable logins	993	(1)
File Security, Ownership, and Sharing	994	(17)
Introduction to File Ownership and Security	994	(1)
Tutorial on File and Directory Permissions	994	(4)
Who Will Own a New File?	998	(1)
Protecting Files with the Sticky Bit	999	(1)
Using chmod to Change File Permission	1000	(1)
The Handy chmod = Operator	1001	(1)
Protect Important Files: Make Them Unwritable	1002	(1)
cx, cw, c--w: Quick File Permission Changes	1003	(1)
A Loophole: Modifying Files Without Write Access	1003	(1)
A Directory That People Can Access but Can't List	1004	(2)
Juggling Permissions	1006	(1)
File Verification with md5sum	1007	(2)
Shell Scripts Must Be Readable and (Usually) Executable	1009	(1)
Why Can't You Change File Ownership?	1009	(1)
How to Change File Ownership Without chown	1010	(1)
SSH	1011	(19)
Enabling Remote Access on Mac OS X	1011	(1)
Protecting Access Through SSH	1011	(1)
Free SSH with OpenSSH	1012	(1)
SSH Problems and Solutions	1013	(1)
General and Authentication Problems	1013	(6)
Key and Agent Problems	1019	(2)
Server and Client Problems	1021	(9)
Glossary	1030	(7)
Index	1037