Std\Process

Process – process management, environment, and command execution.

Provides environment variable access, command execution with output capture, and subprocess management with stdin/stdout pipes. Async functions (exec, execStatus, readAll, wait) block the current fiber without blocking the OS thread.

Functions

getenv : String -> String

Get the value of an environment variable. Returns an empty string if not set.

import getenv from Std\Process in
getenv "HOME"   # => "/home/user"

getcwd : String

Returns the current working directory.

import getcwd from Std\Process in
getcwd   # => "/home/user/project"

exit : Int -> Int

Terminate the process with the given exit code.

import exit from Std\Process in
exit 0

exec : String -> String

Execute a shell command and return its stdout as a string. Async.

import exec from Std\Process in
let output = exec "ls -la" in
println output

execStatus : String -> Int

Execute a shell command and return its exit status code. Async.

import execStatus from Std\Process in
let code = execStatus "make build" in
println (show code)

setenv : String -> String -> Int

Set an environment variable. Returns 0 on success.

import setenv from Std\Process in
setenv "MY_VAR" "hello"

hostname : String

Returns the system hostname.

import hostname from Std\Process in
hostname   # => "myhost"

spawn : String -> Int

Spawn a subprocess without waiting for it to finish. Returns a process handle (Int).

import spawn, wait from Std\Process in
let proc = spawn "sleep 5" in
let status = wait proc in
println (show status)

readLine : Int -> String

Read a single line from the subprocess stdout.

import spawn, readLine from Std\Process in
let proc = spawn "echo hello" in
readLine proc   # => "hello"

readAll : Int -> String

Read all remaining stdout from a subprocess as a string. Async.

wait : Int -> Int

Wait for a subprocess to exit and return its exit status. Async.

kill : Int -> Int -> Int

Send a signal to a subprocess. Returns 0 on success.

import spawn, kill from Std\Process in
let proc = spawn "sleep 100" in
kill proc 15   # SIGTERM

writeStdin : Int -> String -> Int

Write a string to the subprocess stdin. Returns the number of bytes written.

closeStdin : Int -> Int

Close the stdin pipe of a subprocess. Returns 0 on success.

pid : Int -> Int

Returns the OS process ID of a subprocess.

import spawn, pid from Std\Process in
let proc = spawn "sleep 10" in
pid proc   # => 12345