website-monitor

轻量级网站正常运行时间监视器。检查 URL 是否已启动、测量响应时间、通过哈希检测内容更改并验证预期内容。零依赖。

# Website Monitor

A zero-dependency Python tool for checking website availability, measuring response times, and detecting content changes. Uses only Python's standard library (urllib) — no requests, no aiohttp, no external packages.

## Features

- **Uptime checking**: Verify any URL returns the expected HTTP status code
- **Response time measurement**: Precise millisecond timing for each request
- **Content change detection**: SHA-256 based hashing to detect when page content changes between checks
- **Text verification**: Confirm that specific text appears in the response body
- **Multi-URL support**: Check multiple sites in a single command
- **JSON output**: Machine-readable output for integration with other tools and dashboards
- **Exit codes**: Returns exit code 1 if any site is down, making it perfect for shell scripts and cron jobs

## Usage Examples

Simple uptime check:
```bash
python main.py https://example.com
# ✅ https://example.com
#    Status: 200
#    Response: 142ms
#    Size: 1256 bytes
#    Hash: fb91d75a6bb43078
```

Check multiple sites at once:
```bash
python main.py example.com google.com github.com
```

Detect content changes (compare against a previous hash):
```bash
python main.py https://example.com --hash-check fb91d75a6bb43078
# Shows "Changed: YES ⚠️" or "Changed: No"
```

Verify a page contains expected text:
```bash
python main.py https://status.example.com --contains "All Systems Operational"
```

Expect a specific status code (e.g., redirect):
```bash
python main.py https://old.example.com --expect 301
```

JSON output for scripting:
```bash
python main.py example.com github.com --json | jq '.[] | select(.up == false)'
```

Use in a cron job or script:
```bash
python main.py https://mysite.com || echo "ALERT: Site is down!" | mail -s "Downtime Alert" admin@example.com
```

## Command Line Options

- `urls` — One or more URLs to check (auto-prepends https:// if missing)
- `--timeout N` — Request timeout in seconds (default: 10)
- `--expect N` — Expected HTTP status code (default: 200)
- `--contains TEXT` — Verify response body contains this string
- `--hash-check HASH` — Previous content hash to compare against for change detection
- `--json` — Output results as JSON array

## Exit Codes

- `0` — All sites are up and match expectations
- `1` — One or more sites are down or failed checks

---

## 中文说明

# Website Monitor

一个零依赖的 Python 工具，用于检查网站可用性、测量响应时间并检测内容变化。仅使用 Python 标准库（urllib）——无需 requests、aiohttp 或任何外部包。

## 功能

- **正常运行时间检查**：验证任意 URL 是否返回预期的 HTTP 状态码
- **响应时间测量**：为每个请求提供精确到毫秒的计时
- **内容变化检测**：基于 SHA-256 的哈希，检测两次检查之间页面内容是否发生变化
- **文本验证**：确认响应正文中出现特定文本
- **多 URL 支持**：在单条命令中检查多个站点
- **JSON 输出**：机器可读的输出，便于与其他工具和仪表盘集成
- **退出码**：如果任何站点宕机则返回退出码 1，非常适合 shell 脚本和 cron 作业

## 使用示例

简单的正常运行时间检查：
```bash
python main.py https://example.com
# ✅ https://example.com
#    Status: 200
#    Response: 142ms
#    Size: 1256 bytes
#    Hash: fb91d75a6bb43078
```

一次性检查多个站点：
```bash
python main.py example.com google.com github.com
```

检测内容变化（与之前的哈希比较）：
```bash
python main.py https://example.com --hash-check fb91d75a6bb43078
# Shows "Changed: YES ⚠️" or "Changed: No"
```

验证页面包含预期文本：
```bash
python main.py https://status.example.com --contains "All Systems Operational"
```

期望特定状态码（例如重定向）：
```bash
python main.py https://old.example.com --expect 301
```

用于脚本的 JSON 输出：
```bash
python main.py example.com github.com --json | jq '.[] | select(.up == false)'
```

在 cron 作业或脚本中使用：
```bash
python main.py https://mysite.com || echo "ALERT: Site is down!" | mail -s "Downtime Alert" admin@example.com
```

## 命令行选项

- `urls` — 要检查的一个或多个 URL（缺少时自动添加 https:// 前缀）
- `--timeout N` — 请求超时秒数（默认：10）
- `--expect N` — 期望的 HTTP 状态码（默认：200）
- `--contains TEXT` — 验证响应正文包含此字符串
- `--hash-check HASH` — 用于变化检测的之前的内容哈希
- `--json` — 以 JSON 数组形式输出结果

## 退出码

- `0` — 所有站点均正常且符合预期
- `1` — 一个或多个站点宕机或检查失败