更新README.md文档，添加新功能说明、配置覆盖、环境变量支持等

README.md

 # @youdatasum/client-s3
 
-S3 operations client for internal use.
+S3 operations client for internal use. Supports file/folder upload, download, deletion, and listing from S3-compatible storage (RustFS).
 
 ## Installation
 
@@ -28,12 +28,33 @@ Or via Git:
 npm install git+ssh://git@git.youdatasum.com:ljg/client-s3.git
 ```
 
-## Usage
-
-### CLI
+## CLI Usage
 
 After global installation, you can use `ss3ops` command:
 
+### Global Options
+
+All commands support these global options to override S3 configuration:
+
+```bash
+# Override S3 endpoint
+ss3ops --endpoint=http://192.168.2.254:9000 list zhipinku audit/
+
+# Override credentials and endpoint
+ss3ops --endpoint=http://192.168.2.254:9000 --access-key=xxx --secret-key=yyy list zhipinku audit/
+
+# Override region
+ss3ops --region=us-west-2 list zhipinku audit/
+```
+
+Global options:
+- `--endpoint <url>` - S3 endpoint URL (default: `http://192.168.2.253:9000`)
+- `--access-key <key>` - S3 access key ID
+- `--secret-key <key>` - S3 secret access key
+- `--region <region>` - S3 region (default: `us-east-1`)
+
+### Commands
+
 ```bash
 # Download a file
 ss3ops download <bucket> <key> <destination>
@@ -41,24 +62,36 @@ ss3ops download <bucket> <key> <destination>
 # Upload a file
 ss3ops upload <bucket> <key> <source>
 
-# Upload a folder
+# Upload a folder (recursively)
 ss3ops upload-folder <bucket> <prefix> <folder>
-
-> ss3ops  upload-folder zhipinku audit-4520a6ae9d60a234fe-zi  .\audit-4520a6ae9d60a234fe-zi
+# Example: ss3ops upload-folder zhipinku audit-4520a6ae9d60a234fe-zi ./audit-4520a6ae9d60a234fe-zi
 
 # Download a folder
 ss3ops download-folder <bucket> <prefix> <destination>
+# Example: ss3ops download-folder zhipinku audit-4520a6ae9d60a234fe-zi ./downloads/
 
-ss3ops  download-folder zhipinku audit-4520a6ae9d60a234fe-zi   ./xxx
+# Delete a folder and all its contents
+ss3ops delete-folder <bucket> <prefix>
+# Example: ss3ops delete-folder zhipinku audit-4520a6ae9d60a234fe-zi
 
 # List objects in a bucket
 ss3ops list <bucket> [prefix]
+# Example: ss3ops list zhipinku audit/
 ```
 
-### Node.js library
+## Node.js Library Usage
 
 ```javascript
-const { s3, downloadFileFromS3, uploadFileToS3, uploadFolderToS3, downloadS3Folder } = require('@youdatasum/client-s3');
+const { 
+  s3, 
+  createS3Client, 
+  reconfigureS3Client,
+  downloadFileFromS3, 
+  uploadFileToS3, 
+  uploadFolderToS3, 
+  downloadS3Folder,
+  deleteS3Folder 
+} = require('@youdatasum/client-s3');
 
 // Use the pre-configured S3 client (connected to internal RustFS endpoint)
 await s3.send(...);
@@ -71,16 +104,87 @@ const fs = require('fs');
 const body = fs.readFileSync('./local.txt');
 await uploadFileToS3('my-bucket', 'path/to/uploaded.txt', body);
 
-// Upload a folder
+// Upload a folder (recursively uploads all subfolders)
 await uploadFolderToS3('./local-folder', 'my-bucket', 'remote-prefix/');
 
 // Download a folder
 await downloadS3Folder('my-bucket', 'remote-prefix/', './downloads/');
+
+// Delete a folder and all its contents
+const deletedCount = await deleteS3Folder('my-bucket', 'remote-prefix/');
+console.log(`Deleted ${deletedCount} objects`);
+
+// Create a custom S3 client
+const customS3 = createS3Client({
+  endpoint: 'http://192.168.2.254:9000',
+  region: 'us-west-2',
+  credentials: {
+    accessKeyId: 'your-access-key',
+    secretAccessKey: 'your-secret-key'
+  }
+});
+
+// Reconfigure the global S3 client
+reconfigureS3Client({
+  endpoint: 'http://192.168.2.254:9000',
+  credentials: {
+    accessKeyId: 'your-access-key',
+    secretAccessKey: 'your-secret-key'
+  }
+});
 ```
 
 ## Configuration
 
-The S3 client is pre-configured to connect to an internal RustFS endpoint. Credentials and endpoint are hardcoded in the library. If you need to customize, you can modify the `lib/s3-client.js` file.
+The S3 client is pre-configured to connect to an internal RustFS endpoint (`http://192.168.2.253:9000`). You can customize the configuration in multiple ways:
+
+### 1. Environment Variables (Highest priority)
+```bash
+export S3_ENDPOINT=http://192.168.2.254:9000
+export S3_ACCESS_KEY_ID=your-access-key
+export S3_SECRET_ACCESS_KEY=your-secret-key
+export S3_REGION=us-west-2
+```
+
+### 2. Command Line Options
+```bash
+ss3ops --endpoint=http://192.168.2.254:9000 --access-key=xxx --secret-key=yyy list zhipinku audit/
+```
+
+### 3. Programmatic Configuration
+```javascript
+const { createS3Client, reconfigureS3Client } = require('@youdatasum/client-s3');
+
+// Create a new client instance
+const customClient = createS3Client({
+  endpoint: 'http://192.168.2.254:9000',
+  region: 'us-west-2'
+});
+
+// Reconfigure the global client
+reconfigureS3Client({
+  endpoint: 'http://192.168.2.254:9000'
+});
+```
+
+### 4. Modify Source Code (Lowest priority)
+Edit `lib/s3-client.js` directly to change default values.
+
+## Features
+
+- **File Operations**: Upload/download single files
+- **Folder Operations**: Recursive upload/download of folders
+- **Bulk Deletion**: Delete folders with thousands of files (batches of 1000)
+- **Connection Resilience**: Increased timeouts (10s connection, 30s socket) and retry logic
+- **Configurable**: Support for multiple S3 endpoints via environment variables, CLI options, or programmatic configuration
+- **Progress Feedback**: Detailed logging for long-running operations
+
+## Performance Optimizations
+
+- **Batch Processing**: `deleteS3Folder` processes files in batches of 1000 to avoid S3 API limits
+- **Streaming Downloads**: Large files are streamed directly to disk to save memory
+- **Connection Pooling**: Reuses HTTP connections for better performance
+- **Timeout Management**: Configurable timeouts with sensible defaults
 
 ## Development
 
@@ -89,6 +193,18 @@ The S3 client is pre-configured to connect to an internal RustFS endpoint. Crede
 3. Make changes.
 4. Test with `node bin/ss3ops.js`.
 
+### Local Development with npm link
+
+For developing with other projects locally:
+
+```bash
+# In ss3ops directory
+npm link
+
+# In your project directory
+npm link @youdatasum/client-s3
+```
+
 ## Publishing
 
 This package is published to the internal GitLab npm registry. Update version in `package.json` and run:
@@ -99,15 +215,6 @@ npm publish
 
 Ensure you have proper permissions and `publishConfig` points to the correct registry.
 
-
-方案2：使用 npm link
-
- 这个方案是在 ../framework 项目中通过 npm link 链接到本地开发的包。
-
- 步骤：
- 1. 在我们的 ss3ops 目录运行 npm link 创建全局链接
- 2. 在 ../framework 目录运行 npm link @youdatasum/client-s3 链接到本地包
-
 ## License
 
 MIT
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