Porting Open Source (Unix) Software to OpenVMS

This document, "Porting Open Source (Unix) Software to OpenVMS," is a work in progress guide for porting open-source software to the OpenVMS operating system. It aims to help users understand the differences between Unix and OpenVMS environments, set up a porting environment on OpenVMS, build open-source software, and address known porting issues.

The guide covers topics such as:

• Understanding the differences: It explains the characteristics of Unix and OpenVMS, including their file systems, command structures, and standards.
• Setting up the porting environment: This includes building the necessary tools and utilities, configuring system parameters, installing the GNU Not VMS (GNV) kit, and setting up user accounts with appropriate quotas.
• Building open-source software: It details how to use the GNU build system, including downloading source code, unpacking archives, running configure scripts, and compiling software.
• Addressing specific OpenVMS and Unix differences: The document delves into various aspects like the C runtime library, macros, GCC wrapper, fork() and vfork() functions, RMS file system, and common porting issues encountered with specific functions and libraries.
• Appendices: The guide includes appendices that provide an example of porting the m4 utility, a list of known porting issues, a procedure for adding users, and a comparison table of OpenVMS and Unix environments.

The primary audience is anyone interested in porting open-source software to OpenVMS, with an emphasis on those with programming experience, particularly in C and C++. The guide is regularly updated to reflect the ongoing development of porting tools and features in OpenVMS.