The One True Awk

This is the version of awk described in The AWK Programming Language, by Al Aho, Brian Kernighan, and Peter Weinberger (Addison-Wesley, 1988, ISBN 0-201-07981-X).

Copyright

Copyright (C) Lucent Technologies 1997
All Rights Reserved

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name Lucent Technologies or any of its entities not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.

LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

Distribution and Reporting Problems

Changes, mostly bug fixes and occasional enhancements, are listed in FIXES. If you distribute this code further, please please please distribute FIXES with it.

If you find errors, please report them to bwk@cs.princeton.edu. Please also open an issue in the GitHub issue tracker, to make it easy to track issues. Thanks.

Submitting Pull Requests

Pull requests are welcome. Some guidelines:

• Please do not use functions or facilities that are not standard (e.g., strlcpy(), fpurge()).

• Please run the test suite and make sure that your changes pass before posting the pull request. To do so:

  1. Save the previous version of awk somewhere in your path. Call it nawk (for example).
  2. Run oldawk=nawk make check > check.out 2>&1.
  3. Search for BAD or error in the result. In general, look over it manually to make sure there are no errors.

• Please create the pull request with a request to merge into the staging branch instead of into the master branch. This allows us to do testing, and to make any additional edits or changes after the merge but before merging to master.

Building

The program itself is created by

make

which should produce a sequence of messages roughly like this:

yacc -d awkgram.y
conflicts: 43 shift/reduce, 85 reduce/reduce
mv y.tab.c ytab.c
mv y.tab.h ytab.h
cc -c ytab.c
cc -c b.c
cc -c main.c
cc -c parse.c
cc maketab.c -o maketab
./maketab >proctab.c
cc -c proctab.c
cc -c tran.c
cc -c lib.c
cc -c run.c
cc -c lex.c
cc ytab.o b.o main.o parse.o proctab.o tran.o lib.o run.o lex.o -lm

This produces an executable a.out; you will eventually want to move this to some place like /usr/bin/awk.

If your system does not have yacc or bison (the GNU equivalent), you need to install one of them first.

NOTE: This version uses ANSI C (C 99), as you should also. We have compiled this without any changes using gcc -Wall and/or local C compilers on a variety of systems, but new systems or compilers may raise some new complaint; reports of difficulties are welcome.

This compiles without change on Macintosh OS X using gcc and the standard developer tools.

You can also use make CC=g++ to build with the GNU C++ compiler, should you choose to do so.

The version of malloc that comes with some systems is sometimes astonishly slow. If awk seems slow, you might try fixing that. More generally, turning on optimization can significantly improve awk's speed, perhaps by 1/3 for highest levels.

A Note About Maintenance

NOTICE! Maintenance of this program is on a ``best effort'' basis. We try to get to issues and pull requests as quickly as we can. Unfortunately, however, keeping this program going is not at the top of our priority list.

If you (yes, you!) are interested in taking over active maintenance of awk, please open an issue to indicate that fact, and give us a little bit of your background and some idea of your plans and dreams. Thanks!

Last Updated

Tue Oct 13 20:00:09 IDT 2020