prism

prism is a static Rust CLI for small text jobs: dates, random strings, case conversion, slugs, fields, slicing, wrapping, encoding, hashing, templates, and linear record pipelines.

It covers the jobs that usually become printf, date, sed, awk '{print $N}', envsubst, or a throwaway script. It deliberately does not parse structured data. For JSON, YAML, TOML, CSV records, or schema-aware selection, use aq and pipe the result into or out of prism.

Quickstart

# Current UTC date in a fixed format
prism dt --utc --fmt '%Y-%m-%dT%H:%M:%SZ'

# Date arithmetic with an explicit timezone
prism dt --tz America/New_York --at 2026-01-31 +1mo

# Deterministic random token
prism --seed release-demo rand --alnum 24

# Generate a padded sequence
prism seq 1..5 --fmt 'item-%03d'

# Normalize a feature branch name
echo '  My Feature: Fix Auth!  ' | prism do 'trim | case snake | slug'

# Select fields with inclusive dot-dot ranges
echo 'alpha beta gamma delta' | prism field 2..3 --osep ,

# Encode each record independently
printf 'one\ntwo\n' | prism enc hex --per-line

# Hash the whole input by default
printf 'hello' | prism hash sha256

# JSON-render output records
printf 'a b\nc d\n' | prism --json field 2

# NUL-framed records for xargs/find-style pipelines
printf 'a\0b\0' | prism -0 case upper

# Render a small template
prism tpl --set SERVICE=api --set PORT=8080 'service=${SERVICE} port=${PORT}'

# Create and run an alias
prism alias add branchname 'trim | case snake | slug'
echo 'My Feature' | prism run branchname

# Extended version metadata
prism version

Install

Nix development shell

nix-shell
quality

The repo is Nix-first. default.nix provides Rust, cargo-zigbuild, helper scripts, and the local quality gate.

Static Linux binary

Inside the Nix shell:

build_static

Outside the Nix shell, with cargo-zigbuild available:

rustup target add x86_64-unknown-linux-musl
RUSTFLAGS="${RUSTFLAGS:-} -A linker-messages" \
  cargo zigbuild --release --locked --all-features --target x86_64-unknown-linux-musl

GitHub release artifacts

GitHub releases attach compressed binaries for Linux, macOS, and Windows plus SHA256SUMS. Linux release binaries are built with musl for static linking.

Core model

Most commands follow the same pipeline:

acquire input -> split into records -> apply verb -> render records -> join records

Newline is the default record separator. -0 switches both input splitting and output joining to NUL. Text verbs require valid UTF-8. Binary modes such as rand --bytes and hash --raw bypass record framing and do not append a terminator.

Verb classes matter:

Class	Commands	Input behavior
Generators	dt, rand, seq, repeat, pad VALUE	Do not read stdin.
Per-record transforms	case, slug, slice, trim, squeeze, replace, field, stdin-mode pad	Map over records independently.
Whole-stream transforms	wrap, indent, dedent, lines, default enc, default hash, tpl, quote	Consume the full input as one unit unless the verb documents --per-line.

Rendering flags apply after the verb:

Flag	Effect
--json	Render each output record as a JSON string literal.
--raw	Suppress verb-specific quoting where supported. Mutually exclusive with --json.
--no-newline	Drop only the final record terminator.

Environment and config

prism intentionally avoids broad ambient PRISM_* option overrides. The supported environment inputs are explicit:

Variable	Effect
PRISM_TZ	Default timezone for prism dt when --tz and --utc are not set.
TZ	Fallback default timezone for prism dt when PRISM_TZ, --tz, and --utc are not set.
XDG_CONFIG_HOME	Moves the config path used for aliases and [defaults].
Process environment	Exposed to prism tpl as template variables.

Config [defaults] supports seed, count, null, no_newline, raw, json, keep_going, and quiet. Explicit CLI flags win over config defaults.

Template variable precedence is --set KEY=VALUE, process environment, --env-file, then ${VAR:-default} in the template. Use --env-file-override to let dotenv values override process environment values.

Shell completions

prism completions bash > ~/.local/share/bash-completion/completions/prism
prism completions zsh > ~/.zfunc/_prism
prism completions fish > ~/.config/fish/completions/prism.fish

Supported shells are the shells exposed by clap completions, including bash, zsh, fish, powershell, and elvish.

Version metadata

prism --version prints the conventional one-line Cargo package version.

prism version prints extended release metadata, including package version, target, build profile, build commit when available, deterministic RNG contract, and builtin wordlist version.

Release gates

Before release, run:

cargo fmt --check
cargo clippy --all --benches --tests --examples --all-features -- -D warnings
cargo test --all-features
cargo test --no-default-features
cargo build --release --locked --all-features
python3 scripts/release_smoke.py --bin target/release/prism
python3 scripts/perf_matrix.py --build --iterations 5 --warmups 1 --output target/perf-matrix.md

The GitHub release workflow repeats the release smoke and performance smoke gates, builds Linux/macOS/Windows artifacts, writes checksums, and publishes the release.

Known limits

• prism is text-first. Text verbs reject invalid UTF-8. Binary modes are byte-oriented.
• Templates do not shell out and cannot read files from template syntax, but untrusted templates are not a full sandbox. For untrusted templates, use --no-gen, keep recursion off, and run with a clean environment.
• hash and enc operate on the whole input by default. Use --per-line to operate per record.
• -0 changes record framing only. It does not make text transforms accept arbitrary binary data.
• No locale-aware collation or Turkish-i style special casing. Unicode behavior is deterministic and locale-independent.

Docs

• docs/cli.md - command reference.
• docs/examples.md - stable executable examples.
• docs/performance.md - repeatable local performance matrix.
• docs/release.md - GitHub release workflow, artifacts, checksums, and local smoke tests.
• docs/testing.md - test and release acceptance plan.
• docs/status.md - current implementation evidence.

Non-goals

prism does not parse structured data, implement a scripting language, shell out from templates, or provide a full sandbox for untrusted templates.