KBF(3) - Library Functions Manual (prm)
kbf - Brainfuck interpreter written in Korn shell
init();
kbf();
move($index);
cell8($value);
cell16($value);
cell24($value);
cell32s($value);
cell32u($value);
cell64s($value);
output();
input();
nextzero();
prevzero();
stats();
The init() function defines the global variables $instructions, $tape, $instidx and $tapeidx, which are respectively the Instructions Array, the Memory Tape, the Instruction Index and the Tape Index. It also defines two shorthands variables $array and $cell which respectively contains the name of either arrayksh(), arraybash() or arrayzsh() and cell8(), cell16(), cell24(), cell32s(), cell32u(), or cell64s().
The move() function moves the Tape pointer by the amount of bytes contained in $index. This number can be positive or negative. It is not possible to move bellow the position zero or after the position $tflag.
The cell8(), cell16(), cell24(), cell32s(), cell32u(), or cell64s() functions increase or decrease the value under the Tape Pointer, by the amount given as the parameter $value. This value can be positive or negative. It is possible to give a large value that will cause an overflow, also called wrap in Brainfuck terminology. Underflows are also possible. The value at which a cell will wrap depend on the function used. The special value 0 is used to reset the cell value directly at 0.
The
output()
function writes the
ASCII
representation of the byte under the
Tape Pointer.
The
input()
functions writes the value of the
ASCII
byte read from stdin in the
cell under the
Tape Pointer.
The nextzero() function moves the Tape Pointer to the next cell on the right with a value of zero. If none are found, it moves it to the end of the Memory Tape.
The prevzero() function moves the Tape Pointer to the next cell on the left with a value of zero. If none are found, it moves it to the beginning of the Memory Tape.
The stats() function writes statistics about the programme, such as the number of cells used, the number of instructions executed and the state of the Memory Tape.
The kbf() function executes the instructions contained in the Instructions Array with the help of the Instructions Pointer.
The kbf utility is able to transform some parts of the programme into new operators, for performance purpose :
0
Replace the clear loop, [-].
>>
Replace the next zero loop, [>].
<<
Replace the prev zero loop, [<].
This example runs a simple multiplication loop on a Memory Tape already initialized:
. ./kbf.sh
init
$array instructions "+ + + [ > + + + < - ]"
$array tape 5 2
kbf
statskbf(1)
The kbf utility was written by Tristan Le Guern <tleguern@bouledef.eu>.
Linux 4.9.0-3-amd64 - January 18, 2015