cURL commands: advanced usage of GET/POST requests

First, cURL with the correct posture of the proxy

Older drivers of web requests know that cURL is like a toolbox for everything. But many people do not know, to it to install a proxy IP can play with flowers. First of all, the most basic proxy settings, remember the format:-x http://用户名:密码@proxy-address:port. For example, with ipipgo's Dynamic Residential Proxy, it's straightforward to write it this way:

curl -x http://user123:pass456@gateway.ipipgo.com:9024 https://目标网站.com

Here's a pitfall to watch out for:Don't confuse http proxies with https proxies.The ipipgo proxy server supports dual protocols, but some sites verify the protocol type. When you encounter a certificate error, add a-proxy-insecureParameters save lives.

II. Requests for header camouflage practical skills

Now the anti-climbing mechanism is getting more and more refined, the light with the agent is not enough to see. Teach you three combinations:

实战案例：用ipipgo的美国住宅IP+头信息伪装，突破地域限制（注意不涉及）

curl -x http://user:pass@us-proxy.ipipgo.com:9024
-H "User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_7_1)"
-H "Accept-Language: en-US"
https://example.com

Third, the POST request of the tart operation

POST requests are a little more complicated than GET, but with skill it's easy. Focus on remembering the three parameters:

1. -d Passing form data (auto to POST)
2. -data-raw Transmission of raw data
3. -data-binary Transfer binary files

配合代理使用时，记得先测试网络。ipipgo的代理节点响应速度≤50ms，适合高频POST请求。举个上传文件的例子：

curl -x http://file-proxy.ipipgo.com:9024
-F "file=@/path/to/file.zip"
https://upload-site.com

IV. Guidelines for handling difficult cases

Q: What should I do if the proxy works but cURL reports 407 error?
A: 90% is an authentication problem, check the username and password format. ipipgo's username with a business logo, be careful not to miss the prefix!

Q: How do I keep a long connection multiplexing agents?
A: Add parameters-keepalive-time 30And turn ipipgo's session hold on at the same time.

Q: What should I do if I encounter an SSL certificate error?
A: Interim solutions plus-kparameter, but it is recommended to use ipipgo's SSL proxy service, which comes with a legitimate certificate

V. Essential parameters for high-level players

These are a few cold but good parameters that work wonders with proxies:

1. -connect-timeout Set proxy connection timeout (5-10 seconds recommended)
2. -w "%{http_code}" Output status code only
3. -retry 3 automatic retry mechanism

For example, when doing automated collection with ipipgo, you can write this:

curl -x http://scrape-proxy.ipipgo.com:9024
--connect-timeout 8
--retry 2
--w "%{response_code}"
https://target.com/api

One final trick: use-proxy-headerParameters to customize the proxy protocol header, some special scenarios can bypass detection. This requires ipipgo's technical support to configure a specific proxy channel, and should not be used by ordinary users.