介绍
# curl - HTTP Client
用于发出 HTTP 请求和传输数据的命令行工具。
## 基本请求
### GET 请求 ```bash # Simple GET request curl https://api.example.com
# Save output to file curl https://example.com -o output.html curl https://example.com/file.zip -O # Use remote filename
# Follow redirects curl -L https://example.com
# Show response headers curl -i https://example.com
# Show only headers curl -I https://example.com
# Verbose output (debugging) curl -v https://example.com ```
### POST 请求 ```bash # POST with data curl -X POST https://api.example.com/users \ -d "name=John&[email protected]"
# POST JSON data curl -X POST https://api.example.com/users \ -H "Content-Type: application/json" \ -d '{"name":"John","email":"[email protected]"}'
# POST from file curl -X POST https://api.example.com/users \ -H "Content-Type: application/json" \ -d @data.json
# Form upload curl -X POST https://api.example.com/upload \ -F "[email protected]" \ -F "description=My document" ```
### 其他 HTTP 方法 ```bash # PUT request curl -X PUT https://api.example.com/users/1 \ -H "Content-Type: application/json" \ -d '{"name":"Jane"}'
# DELETE request curl -X DELETE https://api.example.com/users/1
# PATCH request curl -X PATCH https://api.example.com/users/1 \ -H "Content-Type: application/json" \ -d '{"email":"[email protected]"}' ```
## 请求头与认证
### 自定义请求头 ```bash # Add custom header curl -H "User-Agent: MyApp/1.0" https://example.com
# Multiple headers curl -H "Accept: application/json" \ -H "Authorization: Bearer token123" \ https://api.example.com ```
### 认证 ```bash # Basic auth curl -u username:password https://api.example.com
# Bearer token curl -H "Authorization: Bearer YOUR_TOKEN" \ https://api.example.com
# API key in header curl -H "X-API-Key: your_api_key" \ https://api.example.com
# API key in URL curl "https://api.example.com?api_key=your_key" ```
## 高级功能
### 超时与重试 ```bash # Connection timeout (seconds) curl --connect-timeout 10 https://example.com
# Max time for entire operation curl --max-time 30 https://example.com
# Retry on failure curl --retry 3 https://example.com
# Retry delay curl --retry 3 --retry-delay 5 https://example.com ```
### Cookies ```bash # Send cookies curl -b "session=abc123" https://example.com
# Save cookies to file curl -c cookies.txt https://example.com
# Load cookies from file curl -b cookies.txt https://example.com
# Both save and load curl -b cookies.txt -c cookies.txt https://example.com ```
### 代理 ```bash # Use HTTP proxy curl -x http://proxy.example.com:8080 https://api.example.com
# With proxy authentication curl -x http://proxy:8080 -U user:pass https://api.example.com
# SOCKS proxy curl --socks5 127.0.0.1:1080 https://api.example.com ```
### SSL/TLS ```bash # Ignore SSL certificate errors (not recommended for production) curl -k https://self-signed.example.com
# Use specific SSL version curl --tlsv1.2 https://example.com
# Use client certificate curl --cert client.crt --key client.key https://example.com
# Show SSL handshake details curl -v https://example.com 2>&1 | grep -i ssl ```
## 响应处理
### 输出格式化 ```bash # Silent mode (no progress bar) curl -s https://api.example.com
# Show only HTTP status code curl -s -o /dev/null -w "%{http_code}" https://example.com
# Custom output format curl -w "\nTime: %{time_total}s\nStatus: %{http_code}\n" \ https://example.com
# Pretty print JSON (with jq) curl -s https://api.example.com | jq '.' ```
### 范围请求 ```bash # Download specific byte range curl -r 0-1000 https://example.com/large-file.zip
# Resume download curl -C - -O https://example.com/large-file.zip ```
## 文件操作
### 下载文件 ```bash # Download file curl -O https://example.com/file.zip
# Download with custom name curl -o myfile.zip https://example.com/file.zip
# Download multiple files curl -O https://example.com/file1.zip \ -O https://example.com/file2.zip
# Resume interrupted download curl -C - -O https://example.com/large-file.zip ```
### 上传文件 ```bash # FTP upload curl -T file.txt ftp://ftp.example.com/upload/
# HTTP PUT upload curl -T file.txt https://example.com/upload
# Form file upload curl -F "[email protected]" https://example.com/upload ```
## 测试与调试
### API 测试 ```bash # Test REST API curl -X GET https://api.example.com/users curl -X GET https://api.example.com/users/1 curl -X POST https://api.example.com/users -d @user.json curl -X PUT https://api.example.com/users/1 -d @updated.json curl -X DELETE https://api.example.com/users/1
# Test with verbose output curl -v -X POST https://api.example.com/login \ -H "Content-Type: application/json" \ -d '{"username":"test","password":"pass"}' ```
### 性能测试 ```bash # Measure request time curl -w "Total time: %{time_total}s\n" https://example.com
# Detailed timing curl -w "\nDNS: %{time_namelookup}s\nConnect: %{time_connect}s\nTLS: %{time_appconnect}s\nTransfer: %{time_starttransfer}s\nTotal: %{time_total}s\n" \ -o /dev/null -s https://example.com ```
### 常用调试 ```bash # Show request and response headers curl -v https://api.example.com
# Trace request curl --trace-ascii trace.txt https://api.example.com
# Include response headers in output curl -i https://api.example.com ```
## 常见模式
**快速 JSON API 测试：** ```bash curl -s https://api.github.com/users/octocat | jq '{name, bio, followers}' ```
**带进度条下载：** ```bash curl -# -O https://example.com/large-file.zip ```
**POST JSON 并提取字段：** ```bash curl -s -X POST https://api.example.com/login \ -H "Content-Type: application/json" \ -d '{"user":"test","pass":"secret"}' | jq -r '.token' ```
**检查 URL 是否可访问：** ```bash if curl -s --head --fail https://example.com > /dev/null; then echo "Site is up" else echo "Site is down" fi ```
**并行下载：** ```bash for i in {1..10}; do curl -O https://example.com/file$i.jpg & done wait ```
## 常用标志
- `-X`：HTTP 方法（GET, POST, PUT, DELETE 等） - `-d`：要发送的数据（POST/PUT） - `-H`：自定义请求头 - `-o`：输出文件 - `-O`：使用远程文件名保存 - `-L`：跟随重定向 - `-i`：在输出中包含请求头 - `-I`：仅输出请求头 - `-v`：详细输出 - `-s`：静默模式 - `-S`：即使在静默模式下也显示错误 - `-f`：HTTP 错误时静默失败 - `-k`：不安全模式（忽略 SSL） - `-u`：基本认证 - `-F`：Multipart 表单数据 - `-b`：发送 cookies - `-c`：保存 cookies - `-w`：自定义输出格式
## 技巧
- 在脚本中使用 `-s` 以禁用进度条 - 组合使用 `-sS` 实现静默模式但显示错误 - 对重定向（如短网址）使用 `-L` - 添加 `-v` 进行调试 - 使用 `jq` 处理 JSON 响应 - 将常用请求保存为 Shell 别名或脚本 - 使用 `--config` 处理复杂的可重用请求
## 文档
官方文档：https://curl.se/docs/ 手册：`man curl` HTTP 方法：https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods