AWK - Versions and Implementations

Versions and Implementations

AWK was originally written in 1977, and distributed with Version 7 Unix.

In 1985 its authors started expanding the language, most significantly by adding user-defined functions. The language is described in the book The AWK Programming Language, published 1988, and its implementation was made available in releases of UNIX System V. To avoid confusion with the incompatible older version, this version was sometimes called "new awk" or nawk. This implementation was released under a free software license in 1996, and is still maintained by Brian Kernighan. (see external links below)

Old versions of Unix, such as UNIX/32V, included awkcc, which converted AWK to C. Kernighan wrote a program to turn awk into C++; its state is not known.

• BWK awk or nawk refers to the version by Brian Kernighan. It has been dubbed the "One True AWK" because of the use of the term in association with the book that originally described the language and the fact that Kernighan was one of the original authors of AWK. FreeBSD refers to this version as one-true-awk. This version also has features not in the book, such as tolower and ENVIRON that are explained above; see the FIXES file in the source archive for details. This version is used by e.g. FreeBSD, NetBSD, OpenBSD and OS X.

• gawk (GNU awk) is another free software implementation and the only implementation that makes serious progress implementing internationalization and localization and TCP/IP networking. It was written before the original implementation became freely available. It includes its own debugger, and its profiler enables the user to make measured performance enhancements to a script, and it also enables the user to extend functionality via shared libraries. Linux distributions are mostly GNU software, and so they include gawk. FreeBSD before version 5.0 also included gawk version 3.0 but subsequent versions of FreeBSD use BWK awk to avoid the more restrictive GNU General Public License (GPL) license as well as for its technical characteristics.

• mawk is a very fast AWK implementation by Mike Brennan based on a byte code interpreter.

• libmawk is a fork of mawk, allowing applications to embed multiple parallel instances of awk interpreters.

• awka (which front end is written atop the mawk program) is another translator of AWK scripts into C code. When compiled, statically including the author's libawka.a, the resulting executables are considerably sped up and, according to the author's tests, compare very well with other versions of AWK, Perl, or Tcl. Small scripts will turn into programs of 160-170 kB.

• tawk (Thompson AWK) is an AWK compiler for Solaris, DOS, OS/2, and Windows, previously sold by Thompson Automation Software (which has ceased its activities).

• Jawk is a project to implement AWK in Java, hosted on SourceForge. Extensions to the language are added to provide access to Java features within AWK scripts (i.e., Java threads, sockets, Collections, etc.).

• jawk (Josh's Awk) is a modern implementation of AWK in Perl, which supports ranges, indexing columns by negative numbers, a Perl mode, and more.

• xgawk is a SourceForge project based on gawk. It extends gawk with dynamically loadable libraries.

• QSEAWK is an embedded AWK interpreter implementation included in the QSE library that provides embedding application programming interface (API) for C and C++.

• BusyBox includes a sparsely documented AWK implementation that appears to be complete, written by Dmitry Zakharov. This is a very small implementation suitable for embedded systems.