BNFerris

Generate random messages based on their BNF (Backus-Naur Form) grammar definitions.

A port of Tsoding's bnfuzzer.

Usage: bnferris [OPTIONS] --file <FILE> --entry <ENTRY>

Options:
  -f, --file <FILE>    Path to the BNF grammar file
  -e, --entry <ENTRY>  The symbol name to start generating from. Use '!' to list all available symbols
  -c, --count <COUNT>  How many messages to generate [default: 1]
      --verify         Verify that all the symbols are defined
      --unused         Verify that all the symbols are used
      --dump           Dump the text representation of the entry symbol
  -h, --help           Print help
  -V, --version        Print version

Quick Start

Generate 10 random postal addresses:

$ cargo run -- -f ./examples/postal.bnf -e postal-address -c 10

Supported Grammar Syntax

This implementation supports both BNF and ABNF syntaxes, allowing for flexible grammar definitions. You can mix and match syntax elements from both formats in the same file.

Core Features

Comments

; BNF-style comment
// C-style comment

Rule Definition

rule = definition

Concatenation

name = part1 part2 part3

Alternatives

choice = one / two    ; ABNF style
choice = one | two    ; BNF style

Incremental Alternatives

rule = alt1 / alt2
rule =/ alt3
rule =/ alt4 / alt5

Equivalent to rule = alt1 / alt2 / alt3 / alt4 / alt5

Value Ranges

Multiple equivalent syntaxes:

digit = %x30-39           ; Hex range
digit = "0" ... "9"       ; Character range
digit = "\x30" ... "\x39" ; Escaped hex range

Grouping

group = item1 (item2 / item3) item4

Repetition

n*mitem    ; Repeat item from n to m times
nitem      ; Exactly n repetitions
*item      ; Zero or more repetitions

Optional Elements

[optional]  ; Zero or one occurrence