diff --git "a/\345\274\240\345\256\207\350\210\252/20260316-\347\254\224\350\256\260+\344\275\234\344\270\232.md" "b/\345\274\240\345\256\207\350\210\252/20260316-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..ec1431807e16f99a09e2428c9e5a2091ce166e5e
--- /dev/null
+++ "b/\345\274\240\345\256\207\350\210\252/20260316-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
@@ -0,0 +1,27 @@
+/_ Node.js Runtime Info _/
+console.log(process.version); // v20.11.0
+console.log(process.versions.node); // 20.11.0
+console.log(process.versions.v8); // 11.3.244.8-jsvc1
+console.log(process.versions.modules); // ABI: 115
+
+/_ Platform & Architecture _/
+console.log(process.platform); // win32 | darwin | linux
+console.log(process.arch); // x64 | arm64 | ia32
+
+/_ Process IDs _/
+console.log(process.pid); // current process id
+console.log(process.ppid); // parent process id
+
+/_ Path Info _/
+console.log(process.cwd()); // working directory
+console.log(process.execPath); // node executable path
+console.log(process.argv[0]); // same as execPath
+console.log(process.argv[1]); // script file path
+
+/_ Memory Usage _/
+console.log(process.memoryUsage());
+// rss: resident memory
+// heapTotal: V8 heap total
+// heapUsed: V8 heap used
+// external: external memory
+// arrayBuffers: ArrayBuffer memory
diff --git "a/\345\274\240\345\256\207\350\210\252/20260318-\347\254\224\350\256\260+\344\275\234\344\270\232.md" "b/\345\274\240\345\256\207\350\210\252/20260318-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..7d5c54a9e7e71a4508b6099a90a53963dedaab8b
--- /dev/null
+++ "b/\345\274\240\345\256\207\350\210\252/20260318-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
@@ -0,0 +1,111 @@
+## 笔记
+const p = require('path');
+
+/* path.join() - join path segments */
+const cfgPath = p.join(__dirname, '..', 'config', 'settings.json');
+// Linux: /project/config/settings.json
+// Windows: C:\project\config\settings.json
+
+/* path.resolve() - resolve to absolute path */
+const fullPath = p.resolve('src', 'index.js');  // based on cwd
+const fullPath2 = p.resolve('/usr', 'local', 'bin');  // /usr/local/bin
+
+/* path info extraction */
+const fp = '/home/user/project/file.txt';
+
+p.basename(fp);         // file.txt
+p.basename(fp, '.txt'); // file
+p.extname(fp);          // .txt
+p.dirname(fp);          // /home/user/project
+
+/* parse path to object */
+p.parse(fp);
+// { root: '/', dir: '/home/user/project', base: 'file.txt', ext: '.txt', name: 'file' }
+
+/* normalize path */
+p.normalize('/foo/bar//baz/../qux');  // /foo/bar/qux
+
+/* calculate relative path */
+p.relative('/data/orandea/test/aaa', '/data/orandea/impl/bbb');
+// ../../impl/bbb
+
+## 作业
+第一题
+// env.js - display environment variables
+console.log('=== Environment Variables ===\n');
+
+// method 1: direct output
+console.log(process.env);
+
+// method 2: formatted
+Object.entries(process.env).sort().forEach(([k, v]) => {
+    console.log(`${k.padEnd(30)} = ${v}`);
+});
+
+// method 3: filter by prefix
+console.log('\n=== Node.js Variables ===');
+Object.keys(process.env)
+    .filter(k => k.startsWith('NODE'))
+    .forEach(k => console.log(`${k}: ${process.env[k]}`));
+
+第二题
+// calc.js - CLI calculator
+const p = require('path');
+
+const params = process.argv.slice(2);
+
+if (params.length < 3 || params.includes('--help')) {
+    console.log(`
+Usage: node calc.js <op> <num1> <num2>
+
+Operations:
+  add  addition (a + b)
+  sub  subtraction (a - b)
+  mul  multiplication (a * b)
+  div  division (a / b)
+
+Examples:
+  node calc.js add 10 5
+  node calc.js mul 3.5 2
+`);
+    process.exit(0);
+}
+
+const [op, num1, num2] = params;
+
+const x = parseFloat(num1);
+const y = parseFloat(num2);
+
+if (isNaN(x) || isNaN(y)) {
+    console.error('Error: invalid numbers');
+    process.exit(1);
+}
+
+let res;
+switch (op) {
+    case 'add':
+        res = x + y;
+        console.log(`${x} + ${y} = ${res}`);
+        break;
+    case 'sub':
+        res = x - y;
+        console.log(`${x} - ${y} = ${res}`);
+        break;
+    case 'mul':
+        res = x * y;
+        console.log(`${x} * ${y} = ${res}`);
+        break;
+    case 'div':
+        if (y === 0) {
+            console.error('Error: division by zero');
+            process.exit(1);
+        }
+        res = x / y;
+        console.log(`${x} / ${y} = ${res}`);
+        break;
+    default:
+        console.error(`Error: unknown operation "${op}"`);
+        process.exit(1);
+}
+
+process.exit(0);
diff --git "a/\345\274\240\345\256\207\350\210\252/20260319-\347\254\224\350\256\260+\344\275\234\344\270\232.md" "b/\345\274\240\345\256\207\350\210\252/20260319-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..d50de428e0806c6272762b693125c4c64003569a
--- /dev/null
+++ "b/\345\274\240\345\256\207\350\210\252/20260319-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
@@ -0,0 +1,103 @@
+## 笔记
+const fs = require('fs');
+const fsp = require('fs').promises;
+
+/* read text file */
+const txt = fs.readFileSync('./readme.md', 'utf8');
+
+/* read binary file */
+const buf = fs.readFileSync('./photo.jpg');  // <Buffer ff d8 ff e0...>
+console.log(`size: ${buf.length} bytes`);
+
+/* read with options */
+const content = fs.readFileSync('./data.txt', {
+    encoding: 'utf8',
+    flag: 'r'
+});
+
+/* promise async way */
+async function loadJson() {
+    const data = await fsp.readFile('./data.json', 'utf8');
+    return JSON.parse(data);
+}
+
+## 作业
+Check file exists? fs.existsSync()
+Write file? fs.writeFileSync() sync / fs.writeFile() async
+appendFileSync vs writeFileSync? append adds content, write overwrites
+Create nested dirs? fs.mkdirSync('./a/b/c', { recursive: true })
+Get file stats? fs.statSync()
+
+// dir-tree.js - directory tree viewer
+const fs = require('fs');
+const p = require('path');
+
+const root = process.argv[2] || '.';
+
+function displayTree(dir, indent = '', isEnd = true) {
+    if (!fs.existsSync(dir)) {
+        console.error(`Path not found: "${dir}"`);
+        process.exit(1);
+    }
+
+    let info;
+    try {
+        info = fs.statSync(dir);
+    } catch (err) {
+        console.error(`Cannot access "${dir}": ${err.message}`);
+        process.exit(1);
+    }
+
+    if (!info.isDirectory()) {
+        console.error(`Not a directory: "${dir}"`);
+        process.exit(1);
+    }
+
+    if (indent === '') {
+        console.log(`[DIR] ${p.resolve(dir)}`);
+    }
+
+    let items;
+    try {
+        items = fs.readdirSync(dir);
+    } catch (err) {
+        console.error(`${indent}└── Read error: ${err.message}`);
+        return;
+    }
+
+    const sorted = items.map(name => {
+        const full = p.join(dir, name);
+        const s = fs.statSync(full);
+        return {
+            name,
+            full,
+            isDir: s.isDirectory(),
+            size: s.size
+        };
+    }).sort((a, b) => {
+        if (a.isDir === b.isDir) return a.name.localeCompare(b.name);
+        return a.isDir ? -1 : 1;
+    });
+
+    sorted.forEach((item, i) => {
+        const end = i === sorted.length - 1;
+        const branch = end ? '└── ' : '├── ';
+        const nextIndent = indent + (end ? '    ' : '│   ');
+        
+        const size = item.isDir ? '' : ` [${formatSize(item.size)}]`;
+        console.log(`${indent}${branch}${item.name}${size}`);
+
+        if (item.isDir) {
+            displayTree(item.full, nextIndent, end);
+        }
+    });
+}
+
+function formatSize(bytes) {
+    if (bytes === 0) return '0 B';
+    const units = ['B', 'KB', 'MB', 'GB'];
+    const idx = Math.floor(Math.log(bytes) / Math.log(1024));
+    return (bytes / Math.pow(1024, idx)).toFixed(1) + ' ' + units[idx];
+}
+
+displayTree(root);
diff --git "a/\345\274\240\345\256\207\350\210\252/20260320-\347\254\224\350\256\260+\344\275\234\344\270\232.md" "b/\345\274\240\345\256\207\350\210\252/20260320-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..cf14fd115209bc92f7a5941ecd5995099ab7161b
--- /dev/null
+++ "b/\345\274\240\345\256\207\350\210\252/20260320-\347\254\224\350\256\260+\344\275\234\344\270\232.md"
@@ -0,0 +1,105 @@
+## 笔记
+
+const http = require('http');
+const url = require('url');
+
+const srv = http.createServer((request, response) => {
+/_ 基础请求信息 _/
+console.log('------------------------');
+console.log('Method:', request.method); // GET/POST/PUT/DELETE
+console.log('URL:', request.url); // /api/users?id=1&name=张三
+console.log('Version:', request.httpVersion); // HTTP/1.1 or HTTP/2
+
+    /* 请求头部 */
+    console.log('Headers:', request.headers);
+    // host, user-agent, accept, content-type, content-length
+
+    /* URL解析处理 */
+    const urlObj = new URL(request.url, `http://${request.headers.host}`);
+    console.log('Path:', urlObj.pathname);            // /api/users
+    console.log('Query:', urlObj.searchParams);       // URLSearchParams
+    console.log('ID:', urlObj.searchParams.get('id')); // "1"
+
+    /* 请求体接收 */
+    let data = '';
+    request.setEncoding('utf8');
+    request.on('data', (segment) => {
+        data += segment;
+        console.log('Received:', segment.length, 'bytes');
+
+        // 防止过大请求
+        if (data.length > 1000000) {
+            request.destroy();
+            response.writeHead(413).end('Payload Too Large');
+        }
+    });
+
+    request.on('end', () => {
+        console.log('Body:', data);
+        // JSON.parse(data) 解析数据
+        response.end('Done');
+    });
+
+    request.on('error', (error) => {
+        console.error('Error:', error);
+    });
+
+});
+
+## 作业
+
+// main.js - 文章接口服务
+const http = require('http');
+const { blogHandler } = require('./blog-controller.js');
+
+const SERVER_PORT = 3000;
+
+const app = http.createServer(async (request, response) => {
+/_ CORS跨域设置 _/
+response.setHeader('Access-Control-Allow-Origin', '\*');
+response.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
+response.setHeader('Access-Control-Allow-Headers', 'Content-Type');
+
+    if (request.method === 'OPTIONS') {
+        response.writeHead(204).end();
+        return;
+    }
+
+    /* 响应格式 */
+    response.setHeader('Content-Type', 'application/json; charset=utf-8');
+
+    try {
+        /* 路由分发 */
+        if (request.url.startsWith('/api/blogs')) {
+            await blogHandler(request, response);
+        } else {
+            response.writeHead(404);
+            response.end(JSON.stringify({
+                success: false,
+                message: 'API not found, use /api/blogs'
+            }));
+        }
+    } catch (error) {
+        console.error('Server Error:', error);
+        if (!response.headersSent) {
+            response.writeHead(500);
+            response.end(JSON.stringify({
+                success: false,
+                message: 'Internal Server Error'
+            }));
+        }
+    }
+
+});
+
+app.listen(SERVER_PORT, () => {
+console.log(`✅ Article API Server Running`);
+console.log(`� http://localhost:${SERVER_PORT}`);
+console.log('');
+console.log('Endpoints:');
+console.log(' GET /api/blogs List all articles');
+console.log(' GET /api/blogs/:id Get single article');
+console.log(' POST /api/blogs Create article');
+console.log(' PUT /api/blogs/:id Update article');
+console.log(' DELETE /api/blogs/:id Delete article');
+});