processExists (processControl.cjs)

Verifies whether a given PID exists in system process tree, checking running process status.

const { spawnSync } = require('node:child_process')

function processExists(pid, kill = process.kill) {
  try {
    kill(Number(pid), 0)
    return true
  } catch {
    return false
  }
}

function childPids(pid, options = {}) {
  const targetPid = Number(pid)
  const exec = options.spawnSync || spawnSync
  if (!Number.isInteger(targetPid) || targetPid <= 1) return []
  try {
    const result = exec('pgrep', ['-P', String(targetPid)], { encoding: 'utf8' })
    if (result.status !== 0) return []
    return String(result.stdout || '')
      .split(/\s+/)
      .map(value => Number(value))
      .filter(value => Number.isInteger(value) && value > 1)
  } catch {
    return []
  }
}

function processTreePids(pid, options = {}) {
  const rootPid = Number(pid)
  const seen = new Set()
  const sta

... (truncated -- full source via MCP)