Run files and projects

lingua run turns a source file or conventional project directory into one predictable command. Lingua selects an installed host runtime, starts it without a shell, bounds output, and owns the timeout.

Run one file

lingua run ./hello.js
lingua run ./analysis.py
lingua run ./hello.go
lingua run ./hello.rs --timeout 60000

JavaScript and TypeScript use Node.js. Python, Go, Rust, Ruby, and Lua use their matching command-line toolchains. If a runtime is missing, Lingua exits with code 3 and names the missing capability.

Pass stdin without a fragile pipe

Use --stdin when the input already lives in a file:

lingua run ./normalize.py --stdin fixtures/raw.txt

A normal pipe also works:

printf 'Ada\nGrace\n' | lingua run ./greet.js

An interactive terminal sends EOF when there is no pipe, so a program that reads stdin does not hang waiting for invisible input.

Forward program arguments

Place Lingua options before --. Every later token reaches the target unchanged:

lingua run ./scripts/check.ts --timeout 45000 -- --verbose --fix src

This is the workaround when your program has an option named --json or --quiet; after the separator, those flags belong to the program.

Add explicit environment values

lingua run ./worker.py \
  --env MODE=development \
  --env FEATURE_X=enabled

--env is repeatable. Lingua does not blindly inherit every parent variable, and it blocks dynamic-loader injection keys plus NODE_OPTIONS. Pass secrets only when the program genuinely needs them; command histories and CI logs can expose arguments.

Run a conventional project

lingua run ./my-project

Detection follows a fixed order:

1. package.json: scripts.start, then scripts.dev, then a valid main.
2. go.mod: go run ..
3. Cargo.toml: cargo run --quiet --.
4. Conventional entries such as main.py, index.js, or src/index.ts.

If a framework requires a special launcher, run that launcher yourself or point Lingua at an independently runnable source file. Lingua does not guess framework-specific commands.

Make automation deterministic

Use --json when another program consumes the result and inspect the process exit code:

if result=$(lingua run ./healthcheck.ts --json); then
  printf '%s\n' "$result" | jq -r '.run.stdout'
else
  printf '%s\n' "$result" | jq -r '.reason' >&2
fi

Plain mode streams while the program runs. JSON mode buffers the same bounded output into one parseable document.