PrismTTY

PrismTTY is a fast terminal output highlighter focused on network devices and Linux/Unix administration. It is intended as a ChromaTerm-style CLI wrapper with network-focused built-in profiles.

Website: prismtty.com.

Current version: 0.2.1.

Preview

Synthetic terminal previews using documentation-only hostnames and addresses:

Install

Homebrew

Install the latest release from the PrismTTY Homebrew tap:

brew install inxbit/tap/prismtty

The Homebrew formula installs prismtty, ptty, ct, bundled profiles, and shell completions. It also installs the required PCRE2 runtime dependency.

Cargo

Install from crates.io:

cargo install prismtty

Cargo builds PrismTTY from source and installs the command binaries. You need Rust 1.85 or newer plus PCRE2 and pkg-config available on your system.

For cargo install on macOS, install the native build dependencies first:

brew install pcre2 pkg-config

For cargo install on Debian/Ubuntu, install:

sudo apt-get install libpcre2-dev pkg-config

GitHub Release

Prebuilt release archives and checksums are available on the v0.2.1 release page.

Each release archive contains the binaries, license/readme files, example profiles, shell completions, and a .tar.gz.sha256 checksum.

Build Locally

Build from a checkout with:

cargo build --release

The project builds these user-facing binaries:

• prismtty
• ptty
• ct

Release packages can be built with:

scripts/package-release.sh darwin-aarch64

The release workflow generates a Homebrew formula from the actual release checksums and uploads it as prismtty.rb with the release artifacts. The published tap formula lives in inxbit/homebrew-tap.

Usage

ptty /bin/zsh
ptty ssh router.example.net
show-tech.txt | prismtty --profile cisco
prismtty profiles test cisco fixtures/cisco.txt
prismtty --reload

The recommended interactive workflow is to start one wrapped shell from your terminal profile:

ptty /bin/zsh

From inside that shell, run normal ssh, telnet, or console-wrapper commands. PrismTTY dynamically switches profiles from observed login banners and prompts, then keeps the selected remote profile locked for the session. Normal command output such as interface descriptions cannot churn the profile in the middle of the session. Nested remote sessions are still supported: a typed remote-jump command arms the next strong banner or repeated prompt to push a new profile, and connection-close markers pop back to the previous profile.

Interactive mode is designed to preserve shell line editing and typed command echo, including zsh prompts that use decorative Unicode prompt markers such as ╰─○, ❯, or ➜.

Use pipe mode for noninteractive output:

show-tech.txt | prismtty --profile cisco
journalctl -xe | prismtty --profile linux-unix

Important options:

• -p, --profile <name> forces one or more profiles.
• --no-auto-detect uses only generic unless profiles are forced.
• --no-dynamic-profile disables profile switching inside wrapped interactive shells.
• -c, --config <file> loads a ChromaTerm-compatible YAML file.
• --strip-ansi removes existing ANSI before PrismTTY styles output.
• --show-profile prints profile selections and transitions to stderr.
• --local-echo locally echoes printable typed keys for no-echo device sessions.
• --trace-io <file> appends hex-encoded PTY input/output plus rendered-output diagnostics.
• -R, --rgb forces RGB color output.
• --pcre is accepted for ChromaTerm compatibility; PCRE2 is always used.
• -b, --benchmark prints per-rule timing and match-count data.
• -r, --reload asks running PrismTTY sessions to reload config.

Profile commands:

prismtty profiles list
prismtty profiles show cisco
prismtty profiles validate ~/.config/prismtty/profiles.d/my-vendor.yml
prismtty profiles test cisco fixtures/cisco.txt

Configuration

PrismTTY loads built-in profiles first, then user rules. By default it checks:

• ~/.chromaterm.yml
• ~/.chromaterm.yaml
• ~/.config/chromaterm/chromaterm.yml
• ~/.config/chromaterm/chromaterm.yaml
• ~/.config/prismtty/config.yml
• ~/.config/prismtty/config.yaml
• /etc/chromaterm/chromaterm.yml
• /etc/chromaterm/chromaterm.yaml
• ~/.config/prismtty/profiles.d/*.yml
• ~/.config/prismtty/profiles.d/*.yaml

ChromaTerm-style rules are supported directly:

rules:
  - description: IPv4
    regex: '\b192\.0\.2\.\d+\b'
    color: f#00ffff

Native profile files add metadata:

profile:
  name: custom-router
  inherits: [generic]
  detection:
    - CustomOS
rules:
  - description: custom interface
    regex: '\bcust\d+/\d+\b'
    color: f#00ffff bold

Profiles under ~/.config/prismtty/profiles.d/ are first-class profiles: they appear in profiles list, can be shown with profiles show, can inherit built-in or other user profiles, and participate in auto-detection through their detection hints.

Built-in profiles are bundled data-driven profile files compiled into the binary. Their private runtime detection metadata is intentionally not part of the public user profile schema yet. If a user profile under profiles.d includes profile.runtime, profiles validate and normal startup loading reject it as a reserved field.

Reload

Long-running ptty /bin/zsh sessions register themselves in a small runtime directory under /tmp by default. Run this after editing ~/.chromaterm.yml or files under ~/.config/prismtty/:

prismtty --reload

The next output chunk in each running PrismTTY session reloads the active config. Set PRISMTTY_RUNTIME_DIR to override the runtime directory, which is useful for tests or isolated sessions.

Built-In Profiles

• generic
• juniper
• cisco
• arubacx
• versa
• arista
• fortinet
• palo-alto
• linux-unix

These profiles are clean-room curated rule sets for prompts, interfaces, addresses, protocol states, syslog severity, operational status, counters, and common vendor terms.

The built-in rule sets and detection hints live as bundled profile data rather than hardcoded vendor branches. Adding or adjusting a built-in profile should start from the bundled profile file and its tests, while user profiles continue to use the public schema shown above. Bundled runtime metadata can also include private negative_signals that block only startup prompt matcher detection; weak detection hints, strong banner signals, and runtime prompt transitions are not blocked by those exclusions.

Interactive dynamic mode keeps built-in vendor selection conservative: after a specific profile such as generic, cisco or generic, juniper is selected, normal command output cannot add another vendor profile. Strong login banners can still switch profiles, and typed nested remote commands can switch after the next strong banner or repeated prompt. Fortinet is intentionally more permissive only from a local-shell baseline: a single hostname # Fortinet prompt can promote to generic, fortinet, which supports local shell wrappers such as fw that do not show a FortiOS banner or an explicit ssh command. Other prompt-only vendor switches still require repeated evidence or a typed remote-jump command.

When PrismTTY is launched as an iTerm profile command, it strips iTerm's native shell-integration variables from the child shell to avoid nested integration marks. The stripped values are preserved under PRISMTTY_PARENT_* names for dotfiles that need session or profile context. For example:

_iterm_session_id="${ITERM_SESSION_ID:-${PRISMTTY_PARENT_ITERM_SESSION_ID:-}}"

if [[ $_iterm_session_id =~ w[0-9]+t0p0 ]]; then
    fastfetch
fi

Development Notes

The CLI entry point is intentionally split into focused internal modules:

• src/cli.rs keeps run(), action dispatch, and CLI error handling.
• src/cli/args.rs owns the clap-backed parser and parser contract tests.
• src/cli/profile_selection.rs loads profile stores, user config, color mode, and profile reporting.
• src/cli/pty.rs owns PTY command execution, raw mode, stdin forwarding, local echo, the iTerm environment guard, and resize polling.
• src/cli/stream.rs owns streaming highlight orchestration, dynamic profile observation, reload handling, benchmarks, and HighlightSession.
• src/cli/runtime.rs owns runtime registration and reload markers.
• src/cli/trace.rs owns --trace-io formatting.

Keep these modules internal to the CLI tree. Parser contract tests intentionally preserve current behavior, including --pcre as a no-op compatibility flag, so future parser migrations can be checked without changing user-facing semantics. The data-driven profile refactor did not keep a temporary old/new detector compatibility module; instead, the current safety net is the runtime transition tests plus byte-for-byte Cisco and Juniper streaming snapshots.

Benchmark

Run the built-in throughput benchmark example:

cargo run --release --example throughput

The example runs router dump, syslog, and mixed-ANSI samples. Runtime benchmark mode is available in normal use:

show-tech.txt | prismtty --benchmark --profile cisco >/dev/null

Replay Fixtures

Replay fixtures under fixtures/replay/ are synthetic. They exist to protect profile detection and streaming coloring behavior across chunk boundaries without checking private device output into the repository.

Run the replay suite with:

cargo test --test replay

When adding a new replay case, use invented hostnames, documentation-range IP addresses, and minimal command output that preserves only the token shape needed for the rule under test. Do not copy real terminal captures into this directory.

License

MIT. See LICENSE.