sed & awk describes two text processing programs that are mainstays of the UNIX programmer's toolbox. sed is 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 with sed is substitution, replacing one block of text with another. awk is a complete programming language. Unlike many conventional languages, awk is "data driven" -- you specify what kind of data you are interested in and the operations to be performed when that data is found. awk does many things for you, including automatically opening and closing data files, reading records, breaking the records up into fields, and counting the records. While awk provides the features of most conventional programming languages, it also includes some unconventional features, such as extended regular expression matching and associative arrays. sed & awk describes both programs in detail and includes a chapter of example sed and awk scripts. This edition covers features of sed and awk that are mandated by the POSIX standard. This most notably affects awk, where POSIX standardized a new variable, CONVFMT, and new functions, toupper() and tolower(). The CONVFMT variable specifies the conversion format to use when converting numbers to strings (awk used to use OFMT for this purpose). The toupper() and tolower() 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 GNU sed, newly available since the first edition. It also updates the first edition coverage of Bell Labs nawk and GNU awk (gawk), covers mawk, an additional freely available implementation of awk, and briefly discusses three commercial versions of awk, MKS awk, Thompson Automation awk (tawk), and Videosoft (VSAwk).

Amazon.com® Reader Reviews (Ranked by Helpfulness)

Average Amazon.com® Rating:  Based on 40 Ratings

Can Replace All of Your SED & AWK Bookmarks (2ndEd) - 2008-08-13
Reviewer Rating:
This book is like a big tutorial series, packed with tons of applicable examples. It is not a reference, that's what the man pages are for, although the index if very good. In fact, the combination of the *BSD man pages and this book would give any man all the SED and AWK documentation he would ever need.

SED and AWK are these two very terse programs that, if you don't use them everyday, you tend to forget their syntax and functionality. I am not an everyday user. Before I bought this book, I often visited one of my many SED/AWK bookmarks. After years of using both programs, I never really understood them. I knew just enough to do small one-liners. However, I recently needed to build a fairly complex script to perform an automated OS upgrade via the network. I knew SED and AWK could help me accomplish my task, but I didn't have a full understanding of their potential. That's when I decided to buy this book. I have since then deleted all of my SED and AWK bookmarks.

After studying this book and highlighting the hell out of it, I have a clear understanding of these two tools and how to effectively utilize them.

Old, but Ok for the porpurse - 2008-04-20
Reviewer Rating:
If you want understand all the sed advanced commands, this book is for you !

I recommend using perl instead sed or awk

Come for the sed, stay for the awk! - 2008-02-16
Reviewer Rating:
This book is a timeless classic, the information on sed is invaluable to anyone who regularly works with text files or streams (after all sed is short for stream editor). Not only is it very informative it's also a fun and easy read... You'll be seeing uses for sed almost every day once you learn how powerful it can be!


The last 1/2 or so is on awk and although it's also very well written and informative it's not quite as useful if you're already experienced with a high level language with excellent text processing facilities like Python or Perl. However, it's work reading even if you keep thinking "I could do this in _____" because sometimes awk really is the right answer.

basic tools to do a basic job - 2008-12-14
Reviewer Rating:
Computers do one basic job, they process data. Often, you do not have control over the output format of the data, but the stuff you want in in there somewhere. So you capture the output to a file, and then chop and hack at it with a text editor to get the data you want in format somewhat like you want.
You can either spend the rest of eternity with a text editor or get these guys, and learn a bit to instruct them to do totally boring but useful drudgery. And perhaps learn about regular expressions and pattern matching. And then do something interesting.
Don't worry, you will have do do it again, if for no other reason than the entity that controls the format of the data decided to change it, for no other reason than to annoy and confound you. But, since you have learned about pattern matching, a minor change will fix it, and you can go back to whatever.
The specific purpose this time was to avoid subscribing to a listing service for cable tv programming. Zap2it publishes the listings on most newspaper websites, and program called wget allows me to write these listings to a file. Then using sed to slice and dice allows me to read simply formatted listings, and eventually feed them to a recording system.

a great little book - 2008-08-26
Reviewer Rating:
I found understanding/writing sed/awk commands/scripts a daunting task until I bought this book. This book empowers you. I rate it at par with "the vi editor" from same publisher

Browse Similar Topics

Top Level Categories:
Operating Systems
Programming

Sub-Categories:
Operating Systems > UNIX
UNIX > Utilities And Tools
Programming > awk