The One True Awk

This is the version of awk described in The AWK Programming Language, Second Edition, by Al Aho, Brian Kernighan, and Peter Weinberger (Addison-Wesley, 2024, ISBN-13 978-0138269722, ISBN-10 0138269726).

What’s New?

This version of Awk handles UTF-8 and comma-separated values (CSV) input.

Strings

Functions that process strings now count Unicode code points, not bytes; this affects length, substr, index, match, split, sub, gsub, and others. Note that code points are not necessarily characters.

UTF-8 sequences may appear in literal strings and regular expressions. Arbitrary characters may be included with \u followed by 1 to 8 hexadecimal digits.

Regular expressions

Regular expressions may include UTF-8 code points, including \u.

CSV

The option --csv turns on CSV processing of input: fields are separated by commas, fields may be quoted with double-quote (") characters, quoted fields may contain embedded newlines. Double-quotes in fields have to be doubled and enclosed in quoted fields. In CSV mode, FS is ignored.

If no explicit separator argument is provided, field-splitting in split is determined by CSV mode.

Copyright

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 the current maintainer, ozan.yigit@gmail.com. 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:

bison -d  awkgram.y
awkgram.y: warning: 44 shift/reduce conflicts [-Wconflicts-sr]
awkgram.y: warning: 85 reduce/reduce conflicts [-Wconflicts-rr]
awkgram.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o awkgram.tab.o awkgram.tab.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o b.o b.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o main.o main.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o parse.o parse.c
gcc -g -Wall -pedantic -Wcast-qual -O2 maketab.c -o maketab
./maketab awkgram.tab.h >proctab.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o proctab.o proctab.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o tran.o tran.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o lib.o lib.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o run.o run.c
gcc -g -Wall -pedantic -Wcast-qual   -O2   -c -o lex.o lex.c
gcc -g -Wall -pedantic -Wcast-qual   -O2 awkgram.tab.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. The default in the makefile is bison; you will have to edit the makefile to use yacc.

NOTE: This version uses ISO/IEC C99, 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.

A Note About Releases

We don’t usually do releases.

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.

Last Updated

Mon 05 Feb 2024 08:46:55 IST