can find a reference for owl in the GNU directory. See here!
The Wikipedia reference for owl 0.7.2. (now gone) is available here in pdf format...
A small hook is still present at esoteric.voxelperfect.net, and precisely here.
I'm very pleased that in the Russian Wikipedia there's a page for FALSE,
in which also owlis explained
Well, I don't ask money for the
programs I create.
But if you want to support my work, feel free to
donate whichever amount,
using the PayPal button down below. In any case, happy surfing!
owl means Obfuscated Weird Language, and it's
my main project
regarding obfuscated programming languages. It was born from the ashes
of bogusforth (another older language of mine, not longer maintained), but it's
different thing. Its
foundations are simplicity, strength and power. You can
download it here.
some of its
was inspired by the great false
programming language by Wouter van Oortmerssen, which in turn lies on
forth constructs; therefore owl
itself lies on forth constructs;
has only 64-bits integer numbers;
simple 64-bits integer stack;
has 26 variables for numbers (letters A-Z) and 26 for
functions (letters a-z);
simple set of math operators and functions and a subset of
simple but powerful (you'll discover how much!)
Let's write the clause that any language must support:
It's the simplest way (that belongs to false
too): a string prints itself. owl
recognizes most of C escape characters, so:
"\tWritten on a sunny \'morning\', listening to America\'s \"A Horse With No Name\"\n"
Written on a sunny 'morning', listening to America's "A Horse
With No Name"
(notice the starting tab, the single and double quotes and the New
Let's see something more intriguing: a program to calculate
Fibonacci numbers available on the environment running owl:
Let's see in detail what happens:
- the ["\n"]c,
(,) in c a
function whose only scope is emitting a new line ("\n")
the title (which is printed), the loop begins (in forth it would be a
REPEAT cycle) with two values on TOS (a couple of ones)
- the two functions that manage this cycle are [%0>]
(the control syntax would sound "until
the number on top of stack is positive") and [%.c@%2'2'+]
(this is the actual algorithm for calculating Fibonacci
- the cycle is executed by the ! command
- the c@
function in c
- the 2'
sequence is a ROT (namely a 2
ROLL in forth style)
- the symbol %
is the DUP command
- the dot . prints top of stack (TOS) consuming it
- the cycle
stops when the number on TOS is negative (see the control function [%0>])
- the ;
drops value on TOS
This program (actually a program
all systems that resolve an integer overflow as a
number (e.g., for what about 64 bits numbers managed by owl
9223372036854775807 + 1 =
-9223372036854775808, which is treated as a negative number [but
there'd be something to say, here! Read the pdf manual!]).
If you want to get amused, see the 99bottles.owl
source example, in which the 99 bottles algorithm can be achieved in owl in no more than
4 lines of code, three of which are strings storing:
[" bottles of
beer"]a,[" bottle of beer"]b,[" on the wall, "]c, [".n"]d,[".nn"]e,["Take
one down and pass it around, "]w, ["no more bottles of
This program returns the following (excerpt):
99 bottles of beer
on the wall, 99 bottles of beer. Take one down and
pass it around, 98 bottles of beer.
98 bottles of beer
on the wall, 98 bottles of beer. Take one down and
pass it around, 97 bottles of beer.
97 bottles of beer
on the wall, 97 bottles of beer. Take one down and
pass it around, 96 bottles of beer. ... ... 3 bottles of beer on
the wall, 3 bottles of beer. Take one down and
pass it around, 2 bottles of beer.
2 bottles of beer on
the wall, 2 bottles of beer. Take one down and
pass it around, 1 bottle of beer.
1 bottle of beer on
the wall, 1 bottle of beer. Take one down and
pass it around, no more bottles of beer.
An even more compact version of this
algorithm (by Marinus Oosters) may be found here.
Documentation for owl consists of
in which owl
basics are explained. Many examples are present. Text format.
the man page,
which is installed by make
and which is actually the quick reference table present into the manual
before version 0.7.4, transformed for man (best viewed into an 80
columns screen or terminal)