chevron

Fast, powerline-styled terminal segments written in Rust (formerly published as plx). Renders path, git status, and tmux window titles using libgit2 — no git subprocess calls.

Install

With Cargo

cargo install chevron

With Nix

nix run github:shiprock/chevron -- path
# or, to install into a profile:
nix profile install github:shiprock/chevron

From source

cargo build --release
# binary lands at target/release/chevron

Usage

chevron <path|git|tmux-title|prompt|init|status|health|weather|...>

• path — Powerline path segment with truncation and home directory collapsing
• git — Git status segment showing branch, staged/modified/untracked counts, ahead/behind, stash, and repo state (rebase, merge, etc.)
• tmux-title — Compact tmux window title with repo name, branch, and dirty indicator
• prompt — Composed prompt line (the main entry point invoked from shell init)
• init — Emit shell hook code (chevron init zsh, chevron init bash, chevron init fish)
• status — Print a recent-commits summary for the current repo
• health — System health probe (load, memory, disk, CPU temp, network)
• weather — One-line current conditions for tmux status-right (see Weather)

Integration

Shell prompt

Add to your shell init:

# zsh / ~/.zshrc
eval "$(chevron init zsh)"

# bash / ~/.bashrc
eval "$(chevron init bash)"

# fish / ~/.config/fish/config.fish
chevron init fish | source

Starship custom modules

[custom.path_segment]
command = "chevron path"
when = "true"
format = "$output"
shell = ["bash", "--nologin"]

[custom.git_segment]
command = "chevron git"
when = "true"
format = "$output"
shell = ["bash", "--nologin"]

Tmux status bar

set -g automatic-rename-format '#(chevron tmux-title)'
# weather in status-right:
set -g status-right '#(chevron weather --units imperial) | %H:%M'

Weather

chevron weather prints a one-line current-conditions summary like Tacoma, US ⛅ 58°F. It is designed to be called from tmux status-right as often as status-interval 1: every failure path (network timeout, parse error, geocode failure, cache miss with no network) exits 0 and prints an empty string. Nothing is ever written to stdout that tmux can't render.

Minimal example

set -g status-right '#(chevron weather --units imperial) | %H:%M'

Zero-config (no API key, no lat/lon): uses Open-Meteo and ifconfig.co for IP geolocation. Both are free and require no signup.

Flags

Flag	Description	Default
--lat FLOAT	Latitude	(IP geolocation)
--lon FLOAT	Longitude	(IP geolocation)
--location-cmd CMD	Shell command whose stdout is "lat|lon"	—
--provider NAME	openmeteo or openweather	openmeteo
--api-key KEY	Required for openweather	—
--units UNITS	metric or imperial	metric
--cache-ttl MIN	Cache TTL in minutes	15
--no-show-city	Hide City, CC prefix	(shown)
--no-show-icon	Hide weather icon	(shown)
--use-nerd-font	Use Nerd Font glyphs instead of Unicode	off
-h, --help	Show help	—

Environment variables

All optional, and lower precedence than CLI flags:

• CHEVRON_WEATHER_LAT, CHEVRON_WEATHER_LON — fixed coordinates
• CHEVRON_WEATHER_LOCATION_CMD — location command (same contract as --location-cmd)
• CHEVRON_WEATHER_PROVIDER, CHEVRON_WEATHER_API_KEY
• CHEVRON_WEATHER_UNITS, CHEVRON_WEATHER_CACHE_TTL
• CHEVRON_WEATHER_DEBUG=1 — log errors to stderr (otherwise fully silent)

TOML configuration

Add a [weather] block to ~/.config/chevron/config.toml:

[weather]
provider = "openmeteo"
units = "imperial"
cache_ttl = 15
show_city = true
show_icon = true
use_nerd_font = true
# api_key = "..."           # for openweather
# lat = 47.13                # optional pinned location
# lon = -122.16
# location_cmd = "my-loc"   # shell command returning "lat|lon"

Precedence: CLI flag > CHEVRON_WEATHER_* env > [weather] TOML > built-in default.

Caching

Rendered output is cached at $XDG_CACHE_HOME/chevron/weather.json (falling back to ~/.cache/chevron/weather.json). A cache hit is a single file read and print — typically single-digit milliseconds, safe for status-interval 1. Entries are keyed on (provider, lat rounded to 2 decimal places, lon rounded to 2 decimal places, units) so switching units or providers does not thrash the cache.

Robustness contract

• Every HTTP call is capped at 3 seconds.
• On network failure, falls back to the previously cached value if present, else empty string.
• chevron weather always exits 0.
• Never writes anything to stdout other than the rendered line or an empty string.

Opting out

The weather subcommand is feature-gated and enabled by default. To build without it (and without the HTTP dependency):

cargo build --release --no-default-features --features banner