Module process_group 

Process-group helpers shared by pipe/pty and shell command execution.

This module centralizes the OS-specific pieces that ensure a spawned command can be cleaned up reliably:

• set_process_group is called in pre_exec so the child starts its own process group.
• detach_from_tty starts a new session so non-interactive children do not inherit the controlling TTY.
• kill_process_group_by_pid targets the whole group (children/grandchildren)
• kill_process_group targets a known process group ID directly instead of a single PID.
• set_parent_death_signal (Linux only) arranges for the child to receive a SIGTERM when the parent exits, and re-checks the parent PID to avoid races during fork/exec.

On non-Unix platforms these helpers are no-ops.

Functions

detach_from_tty

Detach from the controlling TTY by starting a new session.

interrupt_process_group

Send SIGINT to a specific process group ID (best-effort).

kill_child_process_group

Kill the process group for a tokio child (best-effort).

kill_process_group

Kill a specific process group ID (best-effort).

kill_process_group_by_pid

Kill the process group for the given PID (best-effort).

set_parent_death_signal

Ensure the child receives SIGTERM when the original parent dies.

set_process_group

Put the calling process into its own process group.

terminate_process_group

Send SIGTERM to a specific process group ID (best-effort).