termtosvg (Rust port)

THIS IS A PROTOTYPE PORT. DOCUMENTATION MAY BE INCORRECT AND API FUNCTIONALITY MAY BE DIFFERENT THAN EXPECTED. USE AT YOUR OWN RISK.

I am uploading this to crates.io as a test commit to simply see if the following SVG renders in an animated fashion there.

This is ported from the original Python code, and uses a custom test harness to verify the outputs match up.

This crate is a clean-room Rust reimplementation of the original Python termtosvg. It records an interactive terminal session and renders it to a standalone SVG animation (or a still frame) using the same SVG templates shipped with the upstream project.

Quick start

Record a session and emit an SVG in one step (defaults to the powershell template):

cargo run -- --output demo.svg

Record only, keeping the asciicast for later:

cargo run -- record --output demo.cast

Render an existing asciicast with a specific template and still frame mode:

cargo run -- render demo.cast --template window_frame --still-frames --output window_frame.svg

Pipe any command into termtosvg and it will render the incoming text (ANSI colors included) without spawning a child shell:

neofetch | cargo run -- --screen-geometry 82x24 --output neofetch.svg

To render an asciicast streamed on stdin, pass - as the input file:

cat demo.cast | cargo run -- render - --output piped.svg

Rendering from stdin (examples)

You can render asciicast data streamed on stdin using the render - form:

# render an asciicast file piped to stdin
cat demo.cast | cargo run -- render - --output piped.svg

# or with an installed binary
cat demo.cast | termtosvg render - -o piped.svg

If you pipe raw terminal output (not an asciicast) into the program without using the render subcommand, the Rust binary will treat the bytes on stdin as raw terminal output and render a single o event containing that data. This is convenient for single-shot captures where you don't have a cast file:

neofetch | cargo run -- --screen-geometry 82x24 --output neofetch.svg

To explicitly force parsing stdin as an asciicast when piping into the default invocation, use /dev/stdin as the input filename for compatibility with the original Python implementation:

cat demo.cast | termtosvg render /dev/stdin -o piped.svg

--template accepts either a built-in template name (no .svg extension) or a path to a custom SVG template.

Templates

The original templates are vendored under old.python/termtosvg/data/templates and embedded in the binary via include_dir!. The following template names are available out-of-the-box (all of them are pure SVG/CSS animations that remain GitHub-safe):

• base16_default_dark
• dracula
• gjm8
• gjm8_play
• gjm8_single_loop
• powershell
• progress_bar
• putty
• solarized_dark
• solarized_light
• terminal_app
• ubuntu
• window_frame
• window_frame_powershell
• xterm

The legacy window_frame_js template relied on the Web Animations API and inline JavaScript. GitHub strips those scripts, so it is no longer bundled nor supported by the Rust renderer.

Using a built-in template by name

cargo run -- render demo.cast --template solarized_dark --output demo-solarized.svg

Using a template from disk

cargo run -- render demo.cast --template ./old.python/termtosvg/data/templates/window_frame.svg --output window-frame.svg

Customizing a template

1. Copy any SVG from old.python/termtosvg/data/templates to a new location.
2. Edit the <style id="user-style"> block for colors/fonts or add additional SVG/JS elements as described in old.python/man/termtosvg-templates.md.
3. Pass the path to --template when rendering.

The renderer preserves everything in the template except for the generated-style, generated-js, and #screen subtree, so any additional UI you add will show up in the final SVG.

Template parity tests

The parity test renders every default (GitHub-safe) template with both the Python reference renderer and this Rust binary, then compares the DOMs. Run it whenever you modify the renderer or the bundled templates:

python -m venv .venv
. ./.venv/bin/activate
pip install -e old.python
cargo test --test parity -- --ignored --nocapture

Set TERMTOSVG_REFERENCE_BIN if your Python binary is not located at .venv/bin/termtosvg. The test automatically sets the namespace so both renderers produce identical SVG attributes.