bash_run_all_multiple_server(.bashrc))

# --- all: run command or script on local + many hosts (bash-only) ------------
all() {
  # ---- defaults / env ----
  local parallel=${ALL_PARALLEL:-1}          # 1=parallel remotes
  local run_local=${ALL_LOCAL:-1}            # 1=run local too
  local local_parallel=${ALL_LOCAL_PARALLEL:-1}  # 1=local concurrent with remotes
  local timeout=${ALL_TIMEOUT:-8}
  local pty=${ALL_PTY:-0}
  local sudo_n=${ALL_SUDO_N:-1}
  local prefix=${ALL_PREFIX:-1}              # kept for backward compatibility
  local show_ok=${ALL_SHOW_OK:-0}            # 1=print OK lines in summary

  # suppress bash job-control noise
  set +m 2>/dev/null || true
  set +o notify 2>/dev/null || true

  _hdr() { printf '===== %s =====\n' "$1"; }

  # expand "~" at beginning (supports ~ and ~/ ; ~user/ optional)
  _expand_path() {
    local p="$1"
    case "$p" in
      "~")   printf '%s\n' "$HOME" ;;
      "~/"*) printf '%s\n' "$HOME/${p:2}" ;;
      "~"[^/]*/*)
        local u="${p%%/*}"; u="${u:1}"
        local rest="${p#*/}"
        local uh
        uh="$(getent passwd "$u" 2>/dev/null | awk -F: '{print $6}' | head -n1)"
        [[ -n "$uh" ]] && printf '%s\n' "$uh/$rest" || printf '%s\n' "$p"
        ;;
      *)     printf '%s\n' "$p" ;;
    esac
  }

  # ---- hosts ----
  local -a hosts
  if [[ -n "${ALL_HOSTS-}" ]]; then
    read -r -a hosts <<<"$ALL_HOSTS"
  else
    hosts=(192.168.2.5 192.168.2.75)
  fi

  # ---- ssh opts ----
  local -a ssh_opts=()
  if [[ -n "${ALL_SSH_OPTS-}" ]]; then
    read -r -a ssh_opts <<<"$ALL_SSH_OPTS"
  fi

  local -a base_ssh=(ssh -o BatchMode=yes -o ConnectTimeout="$timeout")
  (( pty )) && base_ssh+=( -tt )
  base_ssh+=( "${ssh_opts[@]}" )

  # ---- mode parse ----
  local mode="argv"          # argv|file|stdin
  local script_path="" script_blob=""
  local -a argv=()

  if (( $# == 0 )); then
    if ! -t 0; then
      mode="stdin"
      script_blob="$(cat)"
    else
      echo "Usage:" >&2
      echo "  all <command...>" >&2
      echo "  all @/path/to/script.sh" >&2
      echo "  all <<'SH' ... SH" >&2
      echo "  cat script.sh | all" >&2
      echo "Env: ALL_HOSTS=\"h1 h2\" ALL_PARALLEL=1 ALL_TIMEOUT=8 ALL_SSH_OPTS=\"...\" ALL_PTY=1 ALL_SUDO_N=1 ALL_LOCAL=1" >&2
      return 1
    fi
  else
    if [[ "$1" == @* ]]; then
      mode="file"
      script_path="$(_expand_path "${1#@}")"
      [[ -f "$script_path" ]] || { echo "ERROR: script file not found: $script_path" >&2; return 2; }
      script_blob="$(cat "$script_path")"
      shift || true
      (( $# == 0 )) || { echo "ERROR: extra args after @file are not supported" >&2; return 2; }
    else
      mode="argv"
      argv=( "$@" )
      if (( sudo_n )) && [[ "${argv[0]}" == "sudo" ]]; then
        case " ${argv[*]} " in
          *" sudo -n "*|*" sudo -S "*|*" sudo -A "* ) : ;;
          * ) argv=( sudo -n "${argv[@]:1}" ) ;;
        esac
      fi
    fi
  fi

  # ---- build remote cmd (argv mode) ----
  local remote_cmd="" bash_lc=""
  if [[ "$mode" == "argv" ]]; then
    remote_cmd="$(printf '%q ' "${argv[@]}")"
    bash_lc="$(printf '%q' "$remote_cmd")"
  fi

  # ---- runners ----
  _run_local() {
    if [[ "$mode" == "argv" ]]; then
      "${argv[@]}"
    else
      bash -s <<<"$script_blob"
    fi
  }

  _run_remote() {
    local host="$1"
    if [[ "$mode" == "argv" ]]; then
      "${base_ssh[@]}" "$host" "bash -lc $bash_lc"
    else
      printf '%s' "$script_blob" | "${base_ssh[@]}" "$host" "bash -s"
    fi
  }

  _print_block() {
    local title="$1" rc="$2" file="$3" status
    if (( rc == 0 )); then
      status="OK"
    else
      status="FAIL:$rc"
    fi
    printf '\n===== %s [%s] =====\n' "$title" "$status"
    if [[ -s "$file" ]]; then
      cat "$file"
    else
      printf '(no output)\n'
    fi
  }

  # ---- exec ----
  local tmpdir
  tmpdir="$(mktemp -d "${TMPDIR:-/tmp}/all.XXXXXX")" || return 1
  trap 'rm -rf "$tmpdir"' RETURN

  local -a pids=() names=() titles=() files=() rcs=()
  local rc any_fail=0

  _spawn() {
    local name="$1" title="$2" out="$3"; shift 3
    local pid
    { ( "$@" >"$out" 2>&1 ) & pid=$!; } 2>/dev/null
    pids+=( "$pid" )
    names+=( "$name" )
    titles+=( "$title" )
    files+=( "$out" )
  }

  if (( parallel )); then
    if (( run_local && local_parallel )); then
      _spawn "LOCAL" "LOCAL ($(hostname))" "$tmpdir/LOCAL.log" _run_local
    fi
    local host
    for host in "${hosts[@]}"; do
      _spawn "$host" "$host" "$tmpdir/$host.log" _run_remote "$host"
    done

    local i
    for i in "${!pids[@]}"; do
      wait "${pids[$i]}"; rc=$?
      rcs+=( "$rc" )
      (( rc != 0 )) && any_fail=1
    done

    if (( run_local && ! local_parallel )); then
      names+=( "LOCAL" )
      titles+=( "LOCAL ($(hostname))" )
      files+=( "$tmpdir/LOCAL.log" )
      _run_local >"${files[-1]}" 2>&1; rc=$?
      rcs+=( "$rc" )
      (( rc != 0 )) && any_fail=1
    fi
  else
    if (( run_local )); then
      names+=( "LOCAL" )
      titles+=( "LOCAL ($(hostname))" )
      files+=( "$tmpdir/LOCAL.log" )
      _run_local >"${files[-1]}" 2>&1; rc=$?
      rcs+=( "$rc" )
      (( rc != 0 )) && any_fail=1
    fi
    local host
    for host in "${hosts[@]}"; do
      names+=( "$host" )
      titles+=( "$host" )
      files+=( "$tmpdir/$host.log" )
      _run_remote "$host" >"${files[-1]}" 2>&1; rc=$?
      rcs+=( "$rc" )
      (( rc != 0 )) && any_fail=1
    done
  fi

  # ---- output blocks ----
  local i
  for i in "${!names[@]}"; do
    _print_block "${titles[$i]}" "${rcs[$i]}" "${files[$i]}"
  done

  # ---- summary ----
  local name
  for i in "${!names[@]}"; do
    rc="${rcs[$i]}"
    name="${names[$i]}"
    if (( rc != 0 )); then
      printf 'FAIL (%s): exit=%s\n' "$name" "$rc" >&2
    elif (( show_ok )); then
      printf 'OK   (%s)\n' "$name"
    fi
  done

  (( any_fail )) && return 1
  return 0
}

# --- helpers for your ansible-sync project -----------------------------------
all_add() {
  local path="$1"
  [[ -n "$path" ]] || { echo "Usage: all_add /absolute/path"; return 2; }
  [[ "$path" == /* ]] || { echo "ERROR: use absolute path"; return 2; }
  [[ -e "$path" ]] || { echo "ERROR: not found: $path"; return 2; }

  local proj="$HOME/ansible-sync"
  [[ -d "$proj" ]] || { echo "ERROR: $proj not found"; return 2; }

  echo "$path" >> "$proj/sync_paths.txt"
  echo "Registered: $path"
  ( cd "$proj" && ./bin_sync.sh )
}

all_deploy() {
  local proj="$HOME/ansible-sync"
  [[ -d "$proj" ]] || { echo "ERROR: $proj not found"; return 2; }
  ( cd "$proj" && ./bin_sync.sh )
}