Sed & Awk

by Robbins, Arnold

• ISBN13: 9781565922259
• ISBN10: 1565922255
• Edition: 2nd
• Format: Paperback
• Copyright: 1997-03-01
• Publisher: Oreilly & Associates Inc

Summary

sed & awkdescribes two text processing programs that are mainstays of the UNIX programmer's toolbox.sedis a "stream editor" for editing streams of text that might be too large to edit as a single file, or that might be generated on the fly as part of a larger data processing step. The most common operation done withsedis substitution, replacing one block of text with another.awkis a complete programming language. Unlike many conventional languages,awkis "data driven" -- you specify what kind of data you are interested in and the operations to be performed when that data is found.awkdoes many things for you, including automatically opening and closing data files, reading records, breaking the records up into fields, and counting the records. Whileawkprovides the features of most conventional programming languages, it also includes some unconventional features, such as extended regular expression matching and associative arrays.sed & awkdescribes both programs in detail and includes a chapter of examplesedandawkscripts.This edition covers features ofsedandawkthat are mandated by the POSIX standard. This most notably affectsawk, where POSIX standardized a new variable, CONVFMT, and new functions,toupper() andtolower(). The CONVFMT variable specifies the conversion format to use when converting numbers to strings (awkused to use OFMT for this purpose). Thetoupper() andtolower() functions each take a (presumably mixed case) string argument and return a new version of the string with all letters translated to the corresponding case.In addition, this edition covers GNUsed, newly available since the first edition. It also updates the first edition coverage of Bell Labsnawkand GNUawk(gawk), coversmawk, an additional freely available implementation ofawk, and briefly discusses three commercial versions ofawk, MKSawk, Thompson Automationawk(tawk), and Videosoft (VSAwk).

Author Biography

Dale Dougherty is the publisher of the O'Reilly Network and Director of O'Reilly Research. Dale has been instrumental in many of O'Reilly's most important efforts, including founding O'Reilly & Associates with Tim O'Reilly. He was the developer and publisher of Global Network Navigator (GNN), the first commercial Web site. Dale was developer and publisher of Web Review, the online magazine for Web designers, and he was O'Reilly & Associates' first editor. Dale has written and edited numerous books at O'Reilly & Associates. Dougherty is a Lecturer in the School of Information Management and Systems (SIMS) at the University of California at Berkeley.

Arnold Robbins, an Atlanta native, is a professional programmer and technical author. He has worked with Unix systems since 1980, when he was introduced to a PDP-11 running a version of Sixth Edition Unix. He has been a heavy AWK user since 1987, when he became involved with gawk, the GNU project's version of AWK. As a member of the POSIX 1003.2 balloting group, he helped shape the POSIX standard for AWK. He is currently the maintainer of gawk and its documentation. He is also coauthor of the sixth edition of O'Reilly's Learning the vi Editor. Since late 1997, he and his family have been living happily in Israel.

Table of Contents

Preface	xi
Power Tools for Editing	1	(7)
May You Solve Interesting Problems	1	(2)
A Stream Editor	3	(2)
A Pattern-Matching Programming Language	5	(1)
Four Hurdles to Mastering sed and awk	6	(2)
Understanding Basic Operations	8	(18)
Awk, by Sed and Grep, out of Ed	8	(5)
Command-Line Syntax	13	(2)
Using sed	15	(5)
Using awk	20	(3)
Using sed and awk Together	23	(3)
Understanding Regular Expression Syntax	26	(29)
That's an Expression	27	(2)
A Line-Up of Characters	29	(25)
I Never Metacharacter I Didn't Like	54	(1)
Writing sed Scripts	55	(23)
Applying Commands in a Script	56	(2)
A Global Perspective on Addressing	58	(3)
Testing and Saving Output	61	(3)
Four Types of sed Scripts	64	(13)
Getting to the PromiSed Land	77	(1)
Basic sed Commands	78	(28)
About the Syntax of sed Commands	78	(1)
Comment	79	(1)
Substitution	80	(6)
Delete	86	(1)
Append, Insert, and Change	87	(3)
List	90	(3)
Transform	93	(1)
Print	94	(1)
Print Line Number	95	(1)
Next	95	(1)
Reading and Writing Files	96	(8)
Quit	104	(2)
Advanced sed Commands	106	(31)
Multiline Pattern Space	107	(9)
A Case for Study	116	(3)
Hold That Line	119	(8)
Advanced Flow Control Commands	127	(6)
To Join a Phrase	133	(4)
Writing Scripts for awk	137	(35)
Playing the Game	138	(1)
Hello, World	138	(1)
Awk's Programming Model	139	(2)
Pattern Matching	141	(2)
Records and Fields	143	(4)
Expressions	147	(4)
System Variables	151	(6)
Relational and Boolean Operators	157	(6)
Formatted Printing	163	(3)
Passing Parameters Into a Script	166	(3)
Information Retrieval	169	(3)
Conditionals, Loops, and Arrays	172	(31)
Conditional Statements	172	(2)
Looping	174	(6)
Other Statements That Affect Flow Control	180	(2)
Arrays	182	(11)
An Acronym Processor	193	(6)
System Variables That Are Arrays	199	(4)
Functions	203	(24)
Arithmetic Functions	203	(5)
String Functions	208	(10)
Writing Your Own Functions	218	(9)
The Bottom Drawer	227	(28)
The getline Function	227	(5)
The close() Function	232	(1)
The system() Function	233	(2)
A Menu-Based Command Generator	235	(4)
Directing Output to Files and Pipes	239	(4)
Generating Columnar Reports	243	(3)
Debugging	246	(5)
Limitations	251	(1)
Invoking awk Using the #! Syntax	252	(3)
A Flock of awks	255	(23)
Original awk	255	(4)
Freely Available awks	259	(13)
Commerical awks	272	(5)
Epilogue	277	(1)
Full-Featured Applications	278	(46)
An Interactive Spelling Checker	278	(14)
Generating a Formatted Index	292	(26)
Spare Details of the masterindex Program	318	(6)
A Miscellany of Scripts	324	(35)
uutot.awk---Report UUCP Statistics	325	(3)
phonebill---Track Phone Usage	328	(3)
combine---Extract Multipart uuencoded Binaries	331	(1)
mailavg---Check Size of Mailboxes	332	(1)
adj---Adjust Lines for Text Files	333	(7)
readsource---Format Program Source Files for troff	340	(6)
gent---Get a termacp Entry	346	(2)
plpr---lpr Preprocessor	348	(3)
transpose---Perform a Matrix Transposition	351	(1)
m1---Simple Macro Processor	352	(7)
Quick Reference for sed	359	(6)
Quick Reference for awk	365	(17)
Supplement for Chapter 12	382	(15)
Index	397