A Bash Script to Convert brainfuck Code Into C

Brainfuck is a minimalist Turing Complete language. You can read about it here.

The following bash script takes a file with brainfuck code (legal characters are ><,.+-[] any other characters are ignored), and generates its C equivalent code, which can then be compiled with a C compiler and executed.

The output of this script lacks indentation. If you insist on having the C code indented you can achieve this by passing the output through a pipe to “indent”, “astyle” or similar programs.

The script should be called in the following way:

./bf.sh code.bf > code.c

Where code.bf is the file containing the brainfuck code.

Here is the code:

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#!/bin/bash

echo "int main()"
echo "{"
echo "char pa[30000] = {0};"
echo "char *p = pa;"

#following this conversion table:
# bf cmd | c equivalent
# -----------------------------------
# > | ++p;
# < | --p;
# + | ++*p;
# - | --*p;
# . | putchar(*p);
# , | *p = getchar();
# [ | while (*p) {
# [ | }
#-----------------------------------
sed -e 's/[^]^[^><,.+-]//g' -e 's/[^(><\+\-\.\,\[\])]//g' \
-e 's/>/\P\Pp;\n/g' -e 's/</MMp;\n/g' -e 's/\+/\+\+\*p;\n/g' \
-e 's/-/--\*p;\n/g' -e 's/\./putchar$\*p$;\n/g' \
-e 's/,/\*p = getchar;\n/g' -e 's/\[/while $\*p$ {\n/g' \
-e 's/]/}\n/g' -e 's/P/\+/g' -e 's/M/-/g' "$1"

echo "return 0;"
echo "}"
echo "";

You can also download it here:

Make it executable (chmod +x bf.sh) and you’re ready to go.

For examples of brainfuck programs see the article at Wikipedia.

Enjoy

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Tags: Bash, Programming, sed, Tools

Sunday, June 14th, 2009 Programming

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Hi,
My name is Amir Watad. I have a BSc. in biomedical engineering from The Biomedical Engineering school , Technion , Israel, and am currently studying for a BSc. in electrical engineering at The Electrical Engineering school , Technion , Israel.
I work at the verification dept. in Mellanox Technologies Ltd.
I love Linux, the Command Line and the OpenSource Community.
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