rusty-figlet

Render ASCII-art banners from text. A Rust port of cmatsuoka's figlet(6) v2.2.5 with an in-house FIGfont 2.0 parser, all six horizontal smush rules + universal fallback, 12 bundled .flf fonts via include_bytes!, terminal-width-aware layout, color/rainbow output (toilet-style per-column gradient), byte-equal Strict-mode upstream compatibility, and a typed library API.

Part of the Rusty portfolio.

Install

cargo install rusty-figlet
# or, with prebuilt binaries:
cargo binstall rusty-figlet
# or, download directly from GitHub Releases:
# https://github.com/jsh562/rusty-figlet/releases

Usage

# Default font (standard.flf)
rusty-figlet "Hello"

# Strict-compat (byte-equal upstream figlet v2.2.5 stdout)
rusty-figlet --strict "Hello"

# Font selection (-f <name> | <path>)
rusty-figlet -f slant "Title"
rusty-figlet -f ./my.flf "Hello"
rusty-figlet -d ./fonts -f mycustom "Hello"

# Output width
rusty-figlet -w 120 "wide banner"
rusty-figlet -t "use terminal width"  # auto-applied in Default if stdout is a tty

# Justification (last-wins)
rusty-figlet -c "centered"
rusty-figlet -l "left"
rusty-figlet -r "right"

# Layout overrides (last layout-class flag wins)
rusty-figlet -k "kerning"          # -k
rusty-figlet -W "full width"        # -W
rusty-figlet -S "force smush"       # -S
rusty-figlet -s "font smush"        # -s
rusty-figlet -o "overlap"           # -o
rusty-figlet -m 24 "explicit"       # -m N

# Color + rainbow
rusty-figlet --color=always "color"
rusty-figlet --rainbow "rainbow"   # per-column HSV gradient (toilet-style)

# Paragraph mode (preserve newlines vs collapse)
rusty-figlet -p "paragraph"
rusty-figlet -n "normal"

# Control files (Default: accepted-but-ignored with one-time warning)
rusty-figlet -C custom.flc "Hello"
rusty-figlet -N "Hello"

# Strict mode rejects color flags + control files + completions subcommand
rusty-figlet --strict --color=always "X"   # → exit 2, unrecognized option

Library API

use rusty_figlet::{FigletBuilder, Font};

let figlet = FigletBuilder::new()
    .font(Font::Standard)
    .width(80)
    .build()
    .unwrap();

let banner = figlet.render("X").unwrap();
print!("{banner}");

For library-only consumers without CLI deps:

[dependencies]
rusty-figlet = { version = "0.1", default-features = false }

This strips clap, clap_complete, anstyle, termcolor, and terminal_size, leaving only thiserror (plus the in-house FIGfont parser, smush engine, layout resolver, and Banner iterator).

Cargo Features

default-features = false strips every CLI dep so a library consumer's dep tree contains only rusty-figlet + thiserror + thiserror's pure-Rust transitive deps (verified in tests/library_api.rs).

Compatibility

rusty-figlet has two modes:

• Default — clap-styled flag parser; UTF-8 input; --color/--rainbow enabled; -C/-N accepted-but-ignored with a one-time stderr warning; -t auto-applied when stdout is a tty AND -w is not set; completions subcommand for shell-tab generation.
• Strict (--strict flag, RUSTY_FIGLET_STRICT=1 env, or argv[0] = figlet/figlet-alias) — byte-equal stdout against upstream figlet 2.2.5 for documented diagnostics; Latin-1 input clamp; last-wins flag resolution; rejects -C, -N, --color, --rainbow, completions with upstream-format getopt errors (short: invalid option -- '<char>'; long: unrecognized option '--<name>'); no -t auto-apply.

Precedence for Strict activation: --strict > RUSTY_FIGLET_STRICT env > argv[0]. --no-strict overrides every lower-precedence source; if --strict and --no-strict both appear on the command line, last-wins on the command line per upstream getopt convention.

v0.1.0 excludes

• Vertical smushing (rarely exercised; deferred to v0.2.0)
• Control files (.flc) — -C/-N accepted-but-ignored in Default with one-time warning; rejected under Strict
• Right-to-left rendering (-L/-R) — niche; deferred
• Font-info dump (-I <code>) — debug-only; deferred
• Non-Latin bundled fonts (ivrit, smtengwar, smscript, smshadow, smslant, mnemonic, term) — low signal for the Latin/English 99% target. Users add via -d <dir>.
• Custom non-FIGfont formats (TLF / toilet TLF) — v0.1.0 targets .flf only.

Excluded flags in Strict mode (upstream-format diagnostics)

The program-name token is substituted figlet: → rusty-figlet: per tests/common/mod.rs::strip_for_snapshot; the format of the diagnostic mirrors upstream figlet 2.2.5 getopt byte-for-byte.

BREAKING-CHANGE vs upstream

• stdin 1 MiB cap — rusty-figlet buffers stdin to a 1 MiB hard ceiling; upstream buffers unbounded. One-time stderr warning per process invocation when triggered.
• -C/-N Default behavior — Default mode accepts the flags but emits a one-time control files not yet implemented; ignoring -C/-N stderr warning and proceeds rendering the input as-is (no transliteration). Strict mode rejects with upstream-format invalid option -- 'C' / unrecognized option.
• UTF-8 input in Default — Default mode accepts UTF-8 bytes (Latin-1 + multibyte codepoints) and falls back to the font's missing-character glyph + one-time stderr warning when a codepoint isn't in the font's <hexcode> table. Strict mode clamps input to Latin-1 (ISO-8859-1) bytes-as-codepoints so the upstream byte-equal contract is preserved.
• -t Default auto-apply — Default mode auto-applies -t when stdout is a tty AND -w is not set. Strict mode does NOT auto-apply -t (preserves byte-equal output at width 80).

See docs/COMPATIBILITY.md for the full per-flag matrix.

Lockstep SemVer

rusty-figlet follows the Rusty portfolio SemVer policy:

• MAJOR: change Strict-mode byte-exact output format; change FigletError variant payload signatures; change the SemVer surface of FigletBuilder / Figlet / Banner.
• MINOR: add a new FigletError variant via #[non_exhaustive]; add a new bundled font; add a new CLI flag; add a new FigletBuilder setter.
• PATCH: bug fixes; performance improvements; doc-only changes.

MSRV

Rust 1.85 (edition 2024). Re-verified against the portfolio's stable-minus-two policy at each release.

License

Dual-licensed under MIT or Apache-2.0 at your option. The 12 bundled .flf fonts under assets/fonts/ are redistributed under the Artistic License as preserved in each font's .flf comment header; per-font attribution lives in THIRD_PARTY.md and the Artistic License is compatible with MIT/Apache-2.0 redistribution.