ShellExpression

interface Subprocess<In extends SpawnOptions.Writable = SpawnOptions.Writable, Out extends SpawnOptions.Readable = SpawnOptions.Readable, Err extends SpawnOptions.Readable = SpawnOptions.Readable>

• readonly exitCode: null | number

  Synchronously get the exit code of the process

  If the process hasn't exited yet, this will return null

• readonly exited: Promise<number>

  The exit code of the process

  The promise will resolve when the process exits

• readonly killed: boolean

  Has the process exited?

• readonly pid: number

  The process ID of the child process

  const { pid } = Bun.spawn({ cmd: ["echo", "hello"] });
  console.log(pid); // 1234
  
• readonly readable: ReadableToIO<Out>

  This returns the same value as Subprocess.stdout

  It exists for compatibility with ReadableStream.pipeThrough

• readonly signalCode: null | Signals

  Synchronously get the signal code of the process

  If the process never sent a signal code, this will return null

  To receive signal code changes, use the onExit callback.

  If the signal code is unknown, it will return the original signal code number, but that case should essentially never happen.

• readonly stderr: ReadableToIO<Err>
• readonly stdin: WritableToIO<In>
• readonly stdout: ReadableToIO<Out>
• [Symbol.asyncDispose](): PromiseLike<void>
• disconnect(): void

  Disconnect the IPC channel to the subprocess. This is only supported if the subprocess was created with the ipc option.

• kill(exitCode?: number | Signals): void

  Kill the process

  @param exitCode

  The exitCode to send to the process

• ref(): void

  This method will tell Bun to wait for this process to exit after you already called unref().

  Before shutting down, Bun will wait for all subprocesses to exit by default

• resourceUsage(): undefined | ResourceUsage

  Get the resource usage information of the process (max RSS, CPU time, etc)

  Only available after the process has exited

  If the process hasn't exited yet, this will return undefined

• send(message: any): void

  Send a message to the subprocess. This is only supported if the subprocess was created with the ipc option, and is another instance of bun.

  Messages are serialized using the JSC serialize API, which allows for the same types that postMessage/structuredClone supports.
• unref(): void

  Before shutting down, Bun will wait for all subprocesses to exit by default

  This method will tell Bun to not wait for this process to exit before shutting down.