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.
ftp://ftp.gnu.org/gnu/sed/sed-3.02.tar.gz
The Free Software Foundation's version of sed. The somewhat older version, 2.05, is also available.
http://cm.bell-labs.com/~bwk
Brian Kernighan's home page, with links to the source code for the latest version of awk from Bell Laboratories.
ftp://ftp.freefriends.org/arnold/Awkstuff/mawk1.3.3.tar.gz
Michael Brennan's mawk. A very fast, very robust version of awk.
ftp://ftp.gnu.org/gnu/gawk/gawk-3.1.1.tar.gz
The Free Software Foundation's version of awk, called gawk.
http://awka.sourceforge.net
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.
ftp://ftp.gnu.org/gnu/gettext/gettext-0.11.2.tar.gz
The source code for GNU gettext. Get this if you need to produce translations for your awk programs that use gawk.
1. Dale Dougherty, Arnold Robbins, sed & awk, Second Edition (Sebastopol, Calif.: O'Reilly & Associates, 1997).
2. Alfred V. Aho, Brian W. Kernighan, Peter J. Weinberger, The AWK Programming Language (Reading, Mass.: Addison Wesley, 1988).
3. Arnold Robbins, Effective awk Programming, Third Edition (Sebastopol, Calif.: O'Reilly & Associates, 2001).
4. Brian W. Kernighan, Rob Pike, The Unix Programming Environment (Englewood Cliffs, N.J.: Prentice-Hall, 1984).
5. Arnold Robbins, Unix In A Nutshell, Third Edition (Sebastopol, Calif.: O'Reilly & Associates, 1999).
6. Jon Bentley, Programming Pearls, Second Edition (Reading, Mass.: Addison Wesley, 2000).
7. Jon Louis Bentley, More Programming Pearls: Confessions of a Coder (Reading, Mass.: Addison Wesley, 1988).