Effective awk Programming, 3rd Edition

Foreword

Arnold Robbins and I are good friends. We were introduced 11 years ago by circumstances -- and our favorite programming language, awk. The circumstances started a couple of years earlier. I was working at a new job and noticed an unplugged Unix computer sitting in the corner. No one knew how to use it, and neither did I. However, a couple of days later it was running, and I was root and the one-and-only user. That day, I began the transition from statistician to Unix programmer.

On one of many trips to the library or bookstore in search of books on Unix, I found the gray awk book, a.k.a. Aho, Kernighan, and Weinberger, The AWK Programming Language (Addison Wesley, 1988). awk’s simple programming paradigm -- find a pattern in the input and then perform an action -- often reduced complex or tedious data manipulations to few lines of code. I was excited to try my hand at programming in awk.

Alas, the awk on my computer was a limited version of the language described in the awk book. I discovered that my computer had ``old awk'' and the awk book described ``new awk.'' I learned that this was typical; the old version refused to step aside or relinquish its name. If a system had a new awk, it was invariably called nawk, and few systems had it. The best way to get a new awk was to ftp the source code for gawk from prep.ai.mit.edu. gawk was a version of new awk written by David Trueman and Arnold, and available under the GNU General Public License.

(Incidentally, it’s no longer ...