WSL2環境Claude Codeのセッション状態でターミナルの背景色を塗り分ける方法

#!/usr/bin/env bash
# Claude Code の状態に応じて端末背景色を OSC 11 で切り替える。
# 使い方:
#   term-bg.sh "#14401c"  … その色にする
#   term-bg.sh reset       … デフォルトに戻す
#   term-bg.sh stop        … Stop hook 用。バックグラウンド workflow 実行中なら青、なければ緑
set -u

GREEN="#14401c"
BLUE="#14304a"

# Claude Code 本体が紐づく pts を親プロセスを辿って検出する。
# hook には制御端末 (/dev/tty) が無いため、ps で辿って書き込み先を特定する。
find_pts() {
  local pid=$$ t ppid
  while [ "${pid:-0}" -gt 1 ]; do
    t=$(ps -o tty= -p "$pid" 2>/dev/null | tr -d ' ')
    if [[ "$t" == pts/* ]]; then echo "/dev/$t"; return 0; fi
    ppid=$(ps -o ppid= -p "$pid" 2>/dev/null | tr -d ' ')
    [ -z "$ppid" ] && break
    pid="$ppid"
  done
  return 1
}

# 背景色を適用する ($1 = reset または #RRGGBB)
apply() {
  local dev; dev=$(find_pts) || return 0
  [ -w "$dev" ] || return 0
  if [ "$1" = "reset" ]; then
    printf '\033]111\007' > "$dev"
  else
    printf '\033]11;%s\007' "$1" > "$dev"
  fi
}

arg="${1:-reset}"

if [ "$arg" != "stop" ]; then
  apply "$arg"
  exit 0
fi

# stop: hook の stdin JSON から session_id を取り、workflow 実行中か判定する
sid="$(cat 2>/dev/null | python3 -c '
import sys, json
try:
    print(json.load(sys.stdin).get("session_id") or "")
except Exception:
    print("")
' 2>/dev/null)"

color="$GREEN"
if [ -n "$sid" ]; then
  running="$(python3 - "$sid" <<'PY' 2>/dev/null
import sys, glob, json, os, time
sid = sys.argv[1]
base = os.path.join(os.path.expanduser("~"), ".claude", "projects", "*", sid, "**")
WINDOW = 90
now = time.time()

# agent ログが直近 WINDOW 秒以内に更新されているか (生存確認)
fresh = any(
    now - os.path.getmtime(p) <= WINDOW
    for p in glob.glob(os.path.join(base, "agent-*.jsonl"), recursive=True)
)

# started > result = 未完了エージェントがある
started = result = 0
if fresh:
    for p in glob.glob(os.path.join(base, "journal.jsonl"), recursive=True):
        with open(p, encoding="utf-8") as f:
            for line in f:
                line = line.strip()
                if not line:
                    continue
                try:
                    t = json.loads(line).get("type")
                except Exception:
                    continue
                if t == "started":
                    started += 1
                elif t == "result":
                    result += 1

print(1 if (fresh and started > result) else 0)
PY
)"
  [ "${running:-0}" -gt 0 ] 2>/dev/null && color="$BLUE"
fi

apply "$color"

"hooks": {
  "UserPromptSubmit": [
    { "hooks": [{ "type": "command",
        "command": "bash ~/.claude/scripts/term-bg.sh reset" }] }
  ],
  "PreToolUse": [
    { "matcher": "AskUserQuestion",
      "hooks": [{ "type": "command",
        "command": "bash ~/.claude/scripts/term-bg.sh \"#8a5214\"" }] }
  ],
  "PostToolUse": [
    { "matcher": "AskUserQuestion",
      "hooks": [{ "type": "command",
        "command": "bash ~/.claude/scripts/term-bg.sh reset" }] }
  ],
  "Stop": [
    { "hooks": [{ "type": "command",
        "command": "bash ~/.claude/scripts/term-bg.sh stop" }] }
  ],
  "SessionEnd": [
    { "hooks": [{ "type": "command",
        "command": "bash ~/.claude/scripts/term-bg.sh reset" }] }
  ]
}