Processes and PTY

The process module spawns child processes with piped stdio and provides a real PTY manager for interactive terminals. It is the native building block for embedded terminals, build runners, and language servers.

If you need plain Node child processes, the main process already runs on Node: use child_process there. Use this module when you want the kernel to own the process and stream its output to the UI.

Spawning with pipes

const { procId, pid } = await ow.invoke<{ procId: number; pid: number }>(
  'process', 'spawn',
  '/bin/bash',                 // command
  ['-lc', 'echo hi'],          // args
  '/home/me',                  // cwd
  { FOO: 'bar' },              // env
  false,                       // useShell
)

Signature:

process.spawn(cmd, args?, cwd?, env?, useShell?): Promise<{ procId, pid }>

Stdout/stderr arrive as events to the invoking window:

ow.on('process.stdout', ({ procId, data }) => append(data))
ow.on('process.stderr', ({ procId, data }) => appendError(data))
ow.on('process.exit',   ({ procId, code }) => console.log('exited', code))

Write to stdin and terminate:

await ow.invoke('process', 'write', procId, 'input\n')
await ow.invoke('process', 'kill', procId)            // SIGTERM
await ow.invoke('process', 'kill', procId, 9)         // SIGKILL (number)
await ow.invoke<number[]>('process', 'list')          // live procIds

data may be a string or { b64 } for binary output.

PTY (interactive terminal)

A PTY gives the child a pseudo-terminal, so programs behave interactively (prompts, colors, cursor control). This is the correct backend for a terminal emulator UI.

const { procId, pid } = await ow.invoke<{ procId: number; pid: number }>(
  'process', 'ptyOpen',
  '/bin/bash',        // command
  [],                 // args
  '/home/me',         // cwd
  undefined,          // env (or an object)
  80,                 // cols
  24,                 // rows
)

ow.on('process.stdout', ({ procId, data }) => term.write(data))
await ow.invoke('process', 'write', procId, 'ls\n')
await ow.invoke('process', 'ptyResize', procId, 120, 30)   // on window resize

Signature:

process.ptyOpen(cmd, args?, cwd?, ?, cols?, rows?, env?): Promise<{ procId, pid }>
process.ptyResize(procId, cols, rows): Promise<null>

kill on a PTY closes the master fd, which ends the session.

Platform notes

• Linux: forkpty and pipe/posix_spawn.
• Windows: ConPTY and CreateProcess (verify in CI).
• Commands are passed as an argument array; useShell: true (spawn only) runs them through the system shell.

Next steps

• process module reference.
• Main process — Node's child_process in the sidecar.