add M-w hotkey to watch pane process and notify on completion

tmux/scripts/watch_pane.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+pane_id="$1"
+window_id="$2"
+
+[[ -z "$pane_id" || -z "$window_id" ]] && exit 1
+
+shells="bash zsh fish sh dash ksh tcsh csh"
+
+is_shell() {
+  local cmd="$1"
+  for s in $shells; do
+    [[ "$cmd" == "$s" ]] && return 0
+  done
+  return 1
+}
+
+current_cmd=$(tmux display-message -p -t "$pane_id" '#{pane_current_command}' 2>/dev/null || true)
+[[ -z "$current_cmd" ]] && exit 0
+
+if is_shell "$current_cmd"; then
+  exit 0
+fi
+
+tmux set -w -t "$window_id" @watching 1 2>/dev/null || true
+tmux refresh-client -S
+
+while true; do
+  sleep 1
+  watching=$(tmux show -wv -t "$window_id" @watching 2>/dev/null || true)
+  [[ "$watching" != "1" ]] && exit 0
+  cmd=$(tmux display-message -p -t "$pane_id" '#{pane_current_command}' 2>/dev/null || true)
+  if [[ -z "$cmd" ]] || is_shell "$cmd"; then
+    break
+  fi
+done
+
+tmux set -wu -t "$window_id" @watching 2>/dev/null || true
+tmux set -w -t "$window_id" @unread 1 2>/dev/null || true
+tmux refresh-client -S