This section lists resources for further exploration.
This following URLs indicate where to get source code for GNU sed, four freely available versions of awk, and GNU gettext.
The Free Software Foundation's version of sed. The somewhat older version, 2.05, is also available.
Brian Kernighan's home page, with links to the source code for the latest version of awk from Bell Laboratories.
Michael Brennan's mawk. A very fast, very robust version of awk.
The Free Software Foundation's version of awk, called gawk.
The home page for awka, a translator that turns awk programs into C, compiles the generated C, and then links the object code with a library that performs the core awk functions.
The source code for GNU gettext. Get this if you need to produce translations for your awk programs that use gawk.
Dale Dougherty, Arnold Robbins, sed & awk, Second Edition (Sebastopol, Calif.: O'Reilly & Associates, 1997).
Alfred V. Aho, Brian W. Kernighan, Peter J. Weinberger, The AWK Programming Language (Reading, Mass.: Addison Wesley, 1988).
Arnold Robbins, Effective awk Programming, Third Edition (Sebastopol, Calif.: O'Reilly & Associates, 2001).
Brian W. Kernighan, Rob Pike, The Unix Programming Environment (Englewood Cliffs, N.J.: Prentice-Hall, 1984).
Arnold Robbins, Unix In A Nutshell, Third Edition (Sebastopol, Calif.: O'Reilly & Associates, 1999).
Jon Bentley, Programming Pearls, Second Edition (Reading, Mass.: Addison Wesley, 2000).
Jon Louis Bentley, More Programming Pearls: Confessions of a Coder (Reading, Mass.: Addison Wesley, 1988).