std::process::child

Source: std/process/child.slk

This is the exact canonical documentation page for std::process::child.

Role#

std::process::child is a shipped nested module in the Silk standard library. This exact-name page exists so the module can be discovered and referenced directly by its canonical name.

Canonical Context#

Use the following owning docs for the substantive API/design context for this module:

• process

Notes#

• The shipped source for this module is std/process/child.slk.
• The canonical module name is std::process::child.
• Family-wide semantics, examples, and cross-module relationships live in the owning docs listed above.
• Command owns the backing allocations used by its argument and environment vectors. It implements std::interfaces::Drop; drop() releases both allocations, resets them to empty vectors, and is safe to call repeatedly.
• Child::try_wait() is non-blocking and may be called repeatedly. It returns None while the process is running and a stable cached status after exit.
• Child::wait() returns that same cached status when a preceding try_wait() already observed exit, rather than attempting to reap the process again.
• Child::kill() rejects an already-reaped child, so a cached process ID cannot target an unrelated process after operating-system identifier reuse.
• Child::invalid() is the inert, already-completed sentinel used for safe moves and fallback construction. Its cached status is a successful zero exit, so try_wait() and wait() terminate deterministically without invoking waitpid; operations that require a live process, such as kill, still report invalid input.
• Command::new_process_group() opts spawn, output, or spawn_pty into an owned group without changing the default behavior of ordinary commands. Group establishment completes before a successful spawn result is returned. A failure is classified as ErrorStage::ProcessGroup.
• Child::kill_group(signal) and PtyChild::kill_group(signal) signal only a group explicitly owned by that handle. They reject ordinary, invalid, and already-reaped children, and the raw group identifier is never public.
• To force-stop a supervised tree, call kill_group(signal) before wait(). wait() reaps the direct child; terminated descendants are reaped by their direct parent or the operating system.