PForth - a Portable ANS-like Forth written in ANSI 'C'

by Phil Burk with Larry Polansky, David Rosenboom and Darren Gibbs. Support for 64-bit cells by Aleksej Saushev.

Last updated: November 27, 2022

Portable Forth written in 'C' for most 32 and 64-bit platforms.

PForth is written in 'C' and can be easily ported to new 32 and 64-bit platforms. It only needs character input and output functions to operate and, therefore, does not require an operating system. This makes it handy for bringing up and testing embedded systems.

PForth also works on desktops including Windows, Mac and Linux and supports command line history. This lets you develop hardware tests on a desktop before trying them on your embedded system. But pForth is not a rich and friendly desktop programming environment. There are no GUI tools for developing desktop applications. PForth is lean and mean and optimized for portability.

PForth has a tool for compiling code on a desktop, then exporting the dictionary in big or little endian format as 'C' source code. This lets you compile tests for an embedded system that does not have file I/O.

PForth is based on ANSI-Forth but is not 100% compatible. https://forth-standard.org/standard/words

Code for pForth is maintained on GitHub at: https://github.com/philburk/pforth

Documentation for pForth at: http://www.softsynth.com/pforth/

To report bugs or request features please file a GitHub Issue.

For questions or general discussion please use the pForth forum at: http://groups.google.com/group/pforthdev

LEGAL NOTICE

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

Contents of SDK

platforms - tools for building pForth on various platforms
platforms/unix - Makefile for unix

csrc - pForth kernel in ANSI 'C'
csrc/pf_main.c - main() application for a standalone Forth
csrc/stdio - I/O code using basic stdio for generic platforms
csrc/posix - I/O code for Posix platform
csrc/win32 - I/O code for basic WIN32 platform
csrc/win32_console - I/O code for WIN32 console that supports command line history

fth - Forth code
fth/util - utility functions

How to Build pForth

Building pForth involves two steps: 1) building the C based Forth kernel 2) building the Forth dictionary file using: ./pforth -i system.fth 3) optional build of standalone executable with built-in dictionary

We have provided build scripts to simplify this process.

On Unix and MacOS using Makefile:

cd platforms/unix
make all
./pforth_standalone

For more details, see the Wiki

Using CMake:

cmake .
make
cd fth
./pforth_standalone

For embedded systems, see the pForth reference manual at:

http://www.softsynth.com/pforth/pf_ref.php

How to Run pForth

To run the all-in-one pForth enter:

./pforth_standalone

OR, to run using the dictionary file, enter:

./pforth

Quick check of Forth:

3 4 + .
words
bye

To compile source code files use:

INCLUDE filename

To create a custom dictionary enter in pForth:

c" newfilename.dic" SAVE-FORTH

The name must end in ".dic".

To run PForth with the new dictionary enter in the shell:

pforth -dnewfilename.dic

To run PForth and automatically include a forth file: pforth myprogram.fth

How to Test pForth

PForth comes with a small test suite. To test the Core words, you can use the coretest developed by John Hayes.

On Unix and MacOS using Makefile:

cd platforms/unix
make test

Using CMake:

cmake .
make
cd fth
./pforth
include tester.fth
include coretest.fth

To run the other tests, enter:

pforth t_corex.fth
pforth t_strings.fth
pforth t_locals.fth
pforth t_alloc.fth

They will report the number of tests that pass or fail.

You can also test pForth kernel without loading a dictionary using option "-i". Only the primitive words defined in C will be available. This might be necessary if the dictionary can't be built.

./pforth -i
3 4 + .
23 77 swap .s
loadsys