zena:process
zena
import {…} from 'zena:process';
zena:process — spawning host processes from Zena programs.
WASI itself cannot create processes, so these services are host
imports (wasm module zena_process) that only the zena-cli host
provides — and only to invocations it trusts: its own orchestrator
programs (the bench and test runners), repo tests, and zena-cli run
when passed --allow-spawn (or ZENA_ALLOW_SPAWN=1). Everywhere else
the host links trapping stubs, so importing this library always
compiles for wasi-family targets, but calling into it without the
grant fails loudly at the first call — spawning is a deliberate
sandbox escape and must stay opt-in.
Strings cross the boundary via the $string* helper exports every
Zena module carries; process handles are opaque host references, so
their lifetime is managed by the GC like any other object.
Classes
ProcessResult
zena
class ProcessResult
The captured outcome of a finished process.
Constructors
zena
new()
Properties
zena
exitCode: i32
zena
stdout: String
zena
stderr: String
zena
wallNanos: i64
Wall-clock nanoseconds from spawn to exit.
zena
timedOut: boolean
True when the process overran a waitFor deadline and was killed
rather than exiting on its own. Whatever it had written before the
deadline is still in stdout/stderr.
Methods
zena
succeeded(): boolean
Process
zena
final class Process
A running child process. Both stdout and stderr are captured by the
host (there is no streaming in v1); wait() blocks until the process
exits and returns the captured outcome. Waiting more than once
returns the same result.
Constructors
zena
new(proc: ProcRef)
Methods
zena
wait(): ProcessResult
zena
waitFor(millis: i64): ProcessResult
Waits at most millis for the process to exit, killing it if it
overruns — the result then has timedOut set, and holds whatever
it managed to write first. A non-positive millis waits forever,
so a caller can disable its timeout without branching. Waiting
again returns the same result.
Functions
spawnIn
zena
function spawnIn(argv: Array<String>, cwd: String | null): Process
Start a process without waiting for it. argv[0] is the executable
(resolved against PATH by the host); the child inherits the host's
environment and, with cwd == null, its working directory. Spawning
several processes and waiting on each is how a caller runs work in
parallel. A process that cannot be started at all (e.g. the executable
does not exist) traps with a descriptive message when waited on.
spawn
zena
function spawn(argv: Array<String>): Process
spawnIn with the host's working directory.
runIn
zena
function runIn(argv: Array<String>, cwd: String | null): ProcessResult
Run a process to completion in the given working directory.
run
zena
function run(argv: Array<String>): ProcessResult
Run a process to completion in the host's working directory.