Programming in VAX-11 C

This document, "Programming in VAX-11 C," published in May 1982, is a comprehensive reference manual for experienced programmers developing C programs on Digital Equipment Corporation's VAX-11 computers running the VAX/VMS operating system.

The manual defines the VAX-11 C programming language, covering its fundamental data types (including VAX-specific sizes like 32-bit int), operators, and control flow structures (decisions, loops, and function calls). It details core program structure elements such as function definitions, external data, identifiers, blocks, comments, and keywords, and includes a sample Shell Sort program for C, FORTRAN, and PASCAL comparison.

A significant focus of the document is on VAX-11/VMS-specific features and extensions, crucial for effective development on this platform. These include:

• VAX-Specific Language Elements: It discusses extensions to standard C, such as specific storage classes like globaldef, globalref, globalvalue, and readonly.
• Input/Output (I/O): It provides detailed information on I/O operations, including standard I/O, UNIX I/O emulation functions, and extensive coverage of the VAX-11 Record Management Services (RMS) for managing various file organizations (sequential, relative, indexed) and record access modes.
• Mixed-Language Programming: The guide offers instructions on how to interface C programs with other VAX-11 native-mode languages (FORTRAN, PL/I, and MACRO) by adhering to the VAX-11 Calling Standard and utilizing shared program sections (psects).
• Program Development Tools: It outlines the use of VAX/VMS command-line tools like the CC compiler, LINK linker, and RUN command, along with file specification formats, logical names, and text/object libraries. The EDT editor for source program creation is also detailed.
• Debugging: An introduction to the VAX-11 Symbolic Debugger is provided, explaining its commands, how it interprets symbolic references, and methods for debugging various data types, program flow, breakpoints, and tracepoints.
• Portability: An appendix specifically addresses portability considerations, highlighting differences between VAX-11 C and other C implementations and VAX-11 C's unique functions and extensions.

In summary, the document serves as a complete guide for understanding, developing, compiling, linking, executing, and debugging C programs tailored for the VAX-11/VMS environment prevalent in the early 1980s, offering both core C language reference and critical platform-specific information.