The AWK Programming Language, Second Version

The AWK Programming Language, Second Version

Up to date
Tue Oct 10 13:26:42 EDT 2023

Obtainable in paperback and e-book codecs.
Order at Amazon and different high-quality booksellers.

Introduction

This web page holds materials associated to the
second version of The AWK Programming Language.
The primary version was written by Al Aho, Brian Kernighan and Peter Weinberger
in 1988. Awk has advanced since then, there are a number of implementations,
and naturally the computing world has modified enormously. The brand new
version of the Awk e book displays a few of these modifications.

The e book is now out there on paper and electronically.
We’re persevering with so as to add materials that we hope will likely be of curiosity —
historic paperwork, bits of code, and occasional essays on Awk and
associated matters.

Contact us at information@awk.dev.

Errata

(These are listed in web page quantity order.)

Sep 20, 2023, web page 3, line -5:

The enter line Kathy 15.50 10 must be in italic.
Due to Galen Menzel for recognizing this error.

Oct 6, 2023, web page 9, line -2:

It ought to say “$2 is lower than 20 …” to match the
code. Due to Kevin Lo for recognizing this error.

Oct 10, 2023, web page 24:

The check on the high of the web page must be

NR == 10 { exit }

In any other case the code prints 11 strains, not 10. Due to
Mark Konezny.

Sep 16, 2023, pages 26 and 27:

The streaming model of mc
one web page 26 prints
output in 7 columns, not 5, for the reason that loop begins with n set to zero
and ends with n = 6. Here is a greater model:

{ out = sprintf("%s%-10.10s  ", out, $0)
  if (++n >= 5) {
    print substr(out, 1, size(out)-2)
    out = ""
    n = 0
  }
}

The second model of mc on web page 27 has a unique drawback: it
would not embrace the 2 areas between columns when computing the
variety of columns, so the result’s all the time too excessive. In all probability best
mounted like this:

  ncol = int(60 / (max+2) + 0.5)  # int(x) returns integer worth of x

Many because of 郭济琳 (Jilin Guo) for recognizing these errors.

Oct 8, 2023, web page 32, line 9:

The expression s = s $n++ " " within the perform relaxation
works on Awk however not on Gawk. It is an ambiguity in resolving the
precedences of the prefix $ and the postfix ++.
Fastened by including parentheses:

s = s $(n++) " "

The identical building seems close to the center of the web page and is
mounted in the identical approach.

Due to 郭济琳 (Jilin Guo).

Oct 8, 2023, web page 33, line -10:

The break up perform is healthier written as

break up(date, d)

to correctly deal with single-digit days that could be preceded by
two areas as a substitute of 1. Alternatively, the third argument
may very well be /  +/.

Due to 郭济琳 (Jilin Guo).

Awk for Exploratory Information Evaluation (Sep 21, 2023)

Awk has all the time been an excellent device for taking a fast have a look at some dataset.
What number of objects of what form are there? What’s the vary of numeric
values in some subject? Are there anomalies within the knowledge, like rows with
too many or too few fields?

A brand new chapter within the e book talks about utilizing Awk for this type of
evaluation, utilizing a few datasets. However there are many different
examples as nicely. BWK co-taught a course within the Humanities sequence
at Princeton the place Awk was taught to some very non-technical college students
as a device for some neat knowledge about English poetry.

This essay describes a few of what went on there; it would offer you
some concepts about how Awk can be utilized in a unique area.

Fascinating Threads

Ben Hoyt, creator of
GoAwk and one of many skilled technical reviewers of the second version,
has an attention-grabbing weblog publish on an implementation of the Unix
make command in 60 strains of Awk, together with a Python model
for comparability. One would not make make in Awk, as Ben notes,
nevertheless it’s an excellent car for studying how one thing works. (Sep 21, 2023)

There is a Hacker Information thread on Ben’s authentic publish
here,
with some attention-grabbing feedback.

Awk Supply and Documentation

Awk supply is maintained at
https://github.com/onetrueawk/awk.

Gawk releases are at
https://ftp.gnu.org/gnu/gawk;

the Gawk handbook is
here.

Arnold Robbins has compiled an inventory of

other implementations
of Awk.

Historic Paperwork

The citations within the authentic Awk e book have by now turn into fairly dusty,
however a few of the materials remains to be attention-grabbing and probably helpful.
Listed here are references to a few of the paperwork, maybe up to date.

AWK – A Pattern Scanning and Processing Language,
the unique Awk paper from Software program Follow and Expertise, 1979.

CSTR 118:

An inner technical report on Awk, dated June 1985, so it isn’t the
authentic language however kind of the one described within the Awk e book
in 1988.

dformat:
Dformat is an Awk program, initially written by Jon Bentley,
for drawing data-format diagrams.
The model right here comes from Arnold Robbins (to whom thanks),
who has mounted it up and made it work correctly in immediately’s environments.

chem:

Chem was an experiment in little languages, a language for describing chemical
construction diagrams. (Assume benzene rings on steroids.) It wasn’t a lot used
nevertheless it was an excellent train.

See Also



Worldcoin hit with non permanent ban in Spain over privateness issues

The hyperlink above is to a considerably blurry however full PDF of the unique chem paper
by Bentley, Lynn Jelinski and bwk, revealed in Computational Chemistry in
1987.

indexing programs:

One of many examples within the authentic Awk e book was a simplified model of
indexing instruments first created by Jon Bentley, and used each for each
editions of the e book. The hyperlink above offers the code; the
paper was revealed in
Digital Publishing — Origination Dissemination and Design in 1988.
The second version of the e book has considerably modified code.
Due to Taj Khattra for locating the EP-ODD supply.

Algorithm animation:
by Jon Bentley and bwk.
The paper A System for Algorithm Animation (1991) describes a
system for embedding easy graphics instructions in program output that
may very well be used to show an “animated” model of the output. All of it
labored on monochrome shows, so it’s very dated now, nevertheless it was
neat on the time. The unique Computing Science Technical Report (CSTR) 132 is
here.

Netlib’s typesetting collection
Contains some hyperlinks to chem and indexing applications

Interview with Al Aho
about Awk in Computerworld, Could 2008

Interview with Brian Kernighan about Awk and AMPL, Computerworld, October 2009

Autre temps, autres Awks

awk.information (dmr) Tue Jul 15 23:47:57 1986

   Rosa Miller, a Tlinget [sic] Indian who lives in Juneau, ... is a member
   of the Dipper Home of the Canine Salmon Clan of the Raven Moiety of the
   Awk Tribe of the Tlingit (pronounced KLINK-it) Nation....

   Mrs. Miller contends that the Awk Tribal Council in Juneau was arrange by
   individuals who weren't Awks however, as she calls them, "Johnny come latelies"
   to the world....
	   New York Instances, 7/14, p. A8

   CORRECTION

   Due to a transmission error, the Alaska Journal yesterday,
   from Anchorage, misidentified an Indian tribe.  It's the Auk, not Awk.
	   New York Instances, 7/15, p. B1

Awk (adj, obs;  additionally awke, auk, awck) [from ON afug, turned the wrong way, back foremost, perverse]

1. Directed the opposite approach or within the flawed path, back-handed, from the left hand.
1634:  "With an awke stroke gaue hym a grete wounde."

2. Untoward, froward, perverse, in nature or disposition.
1642:  "Our natures extra crooked, inconstante, awk, and perverse."

3. Out of the way in which, odd, unusual (uncommon) [fortunately]

4. Untoward to take care of, awkward to make use of, clumsy.

There are additionally awkly, awkness, awkward, awkwardish, awkwardly, awkwardness, and awky.

In Scotland, upon April Day, they've a customized of ``searching the gowk
...', correctly, a cuckoo, and is used right here, metaphorically in vulgar
language, for a idiot.  That is completed by sending foolish folks upon
fools' errands from place to put, by way of a letter through which it
is written: ``On the primary day of April, Hunt the gowk one other mile.''

		John Model's ``Observations on Standard Antiquities, 1813''
		(c) Jeffrey Kacirk

This triumph of the advertiser’s artwork did not final very lengthy,
sadly. We’re grateful to A&W Eating places for his or her
assist.

A cartoon from Russell Myers’ Broom Hilda in June 2018:

Ozan Yigit noticed this paintings on a Danish TV present and recognized it with
Google picture search: A lithographic artwork print by Gérard Gasiorowski from
Galerie Maeght in Paris for an exhibition in 1982.

An outdated however good cartoon from Person Pleasant, by J. D. “Illiad” Frazer:

Do you might have one so as to add? Ship it alongside! Mail to information@awk.dev.