code/scripts/launch_after.sh

#!/usr/bin/env bash
# scripts/launch_after.sh
#
# Wait for a PID to exit, then fire a launcher script. Designed to be
# itself run detached under nohup, so an SSH disconnect during the wait
# doesn't stop the watcher.
#
# Usage:
#   nohup bash scripts/launch_after.sh <pid> <launcher.sh> [args...] \
#       > logs/install/<stamp>_watcher/wait.log 2>&1 &
#
# Or via the helper:
#   bash scripts/launch_after_detached.sh <pid> <launcher.sh> [args...]

set -euo pipefail

ROOT="$(cd "$(dirname "$0")/.." && pwd)"
cd "${ROOT}"

if [[ $# -lt 2 ]]; then
    echo "usage: $0 <pid> <launcher.sh> [args...]" >&2
    exit 2
fi

PID="$1"; shift
LAUNCHER="$1"; shift

echo "[$(date -u +%FT%TZ)] watching PID ${PID}; will fire ${LAUNCHER} $* when it ends"
while kill -0 "${PID}" 2>/dev/null; do sleep 30; done
echo "[$(date -u +%FT%TZ)] PID ${PID} exited; firing ${LAUNCHER}"
exec bash "${LAUNCHER}" "$@"