Forth Hello World Example: How To Write and Execute Forth Program on Linux OS

Question: I would like to understand the basics of how to write and execute Forth program on Linux OS. Can you explain it with a simple example?

Answer: If you’ve never heard about Forth program, read about it in Wikipedia first. In this article, let us review very quickly how to write a basic Hello World Forth program, and run forth program on Linux or Unix OS.

1. Write a Hello World Forth Program

Create the helloworld program using the Vim editor as shown below.

$ vim helloworld.fth

\ hello world forth program.
.( Hello World!) CR

Note: Comment in Forth starts with \

2. Make sure Forth command line interpreter is installed on your system

Make sure Forth interpreter is installed on your system as shown below.

$ whereis pforth
pforth: /usr/bin/pforth /usr/lib/pforth /usr/share/man/man1/pforth.1.gz

Installing forth interpreter

If you don’t have forth interpreter, install it as shown below.

$ sudo apt-get install pforth

3. Execute the forth Program

Execute forth program as shown below.

$ pforth helloworld.fth
PForth V21
pForth loading dictionary from file /usr/lib/pforth/pforth.dic
     File format version is 8
     Name space size = 120000
     Code space size = 300000
     Entry Point     = 0
     Little  Endian Dictionary
Begin AUTO.INIT ------
Including: helloworld.fth
Hello World!
End AUTO.TERM ------