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1 Introduction

GNU AWK (gawk) 5.2, expected in September 2022, introduces a new persistent memory feature that makes AWK scripting easier and sometimes improves performance. The new feature, called “pm-gawk,” can “remember” script-defined variables and functions across executions and can pass variables and functions between unrelated scripts without serializing/parsing text files—all with near-zero fuss. pm-gawk does not require non-volatile memory hardware nor any other exotic infrastructure; it runs on the ordinary conventional computers and operating systems that most of us have been using for decades.

The main gawk documentation¹ covers the basics of the new persistence feature. This supplementary manual provides additional detail, tutorial examples, and a peek under the hood of pm-gawk. If you’re familiar with gawk and Unix-like environments, dive straight in:

• Quick Start hits the ground running with a few keystrokes.
• Examples shows how pm-gawk streamlines typical AWK scripting.
• Performance covers asymptotic efficiency, OS tuning, and more.
• Data Integrity explains how to protect data from mishaps.
• Acknowledgments thanks those who made pm-gawk happen.
• Installation shows where obtain pm-gawk.
• Debugging explains how to handle suspected bugs.
• History traces pm-gawk’s persistence technology.

You can find the latest version of this manual, and also the “director’s cut,” at the web site for the persistent memory allocator used in pm-gawk:

Two publications describe the persistent memory allocator and early experiences with a pm-gawk prototype based on a fork of the official gawk sources:

• https://queue.acm.org/detail.cfm?id=3534855
• http://nvmw.ucsd.edu/nvmw2022-program/nvmw2022-data/nvmw2022-paper35-final_version_your_extended_abstract.pdf

Feel free to send me questions, suggestions, and experiences:

                tpkelly@eecs.umich.edu   (preferred)
                tpkelly@cs.princeton.edu
                tpkelly@acm.org