cURL Parameters: cURL Common Parameters Explained

First, curl this thing in the end how to play the proxy?

We usually use curl to grab data, often encounter the target site blocked IP situation. At this time the proxy IP will become a lifesaver, take ipipgo's proxy service as a chestnut, their dynamic residential IP pool thief, especially suitable for the need to frequently switch IP scenarios.

The most basic proxy setup parameters look like this:

curl --proxy http://username:password@ipipgo-proxy-server:port https://target-site.com

Note that the username and password replaced by ipipgo background to your authentication information, port number do not fill in the wrong. Many newbies fall into thePasswords with special characters are not escaped这事儿上，比如密码里有@符号的话，得改成%40才行。

Second, hide your little tail

Some websites are so smart that they will detect the User-Agent, and it's not enough to just change the IP, you have to add it:

curl -A "Mozilla/5.0 (Windows NT 10.0)..." --proxy http://ipipgo-proxy-server:port...

ipipgo's tech guy told me that their clients who do e-commerce price monitoring have to work with this parameter to use a high stash of proxies, or else they'll be cracked in minutes.

Thirdly, there are rules for setting a net overtime.

Proxy network instability is a common occurrence, and these parameters can be a lifesaver:

This is how it is recommended to match in real life:

curl --connect-timeout 15 --max-time 30 --retry 2...

IV. Debugging black technology

What should I do if I can't connect to the proxy? Turn on detailed mode first and see:

curl -v --proxy http://ipipgo-proxy-server:port...

Focus on these places in the output:
- Is the proxy connection successfully established?
- Status code returned by the target server
- There's no HTTPS tunnel.

V. Practical QA

Q: What's wrong with the agent not being able to connect all the time?
A: First check the proxy address port right, ipipgo users remember to check the latest server address in the background, they will update the node every month.

Q：Downloading large files is always interrupted?
A: Try -limit-rate 500k speed limit, and with ipipgo's enterprise-class proxy package, their exclusive bandwidth is really stable.

Q: What if I need to use more than one agent at the same time?
A: You can write a shell script to rotate proxies, ipipgo's API can get the available IP in real time, with the use of the beauty.

Lastly, you have to look at the response time when choosing a proxy service provider. Like ipipgo with intelligent routing, automatic selection of the fastest node is really worry-free. Recently, they have been carrying out activities for new users to send 10G traffic, used to practice is just right.