What is curl: Command Line HTTP Transfer Tool Explained

What the hell is curl?

Speaking of curl, this thing is like your downstairs courier, specifically responsible for helping you send and receive data packages on the Internet. It is a command line tool, no mouse point and click, knock a few commands to complete the web page access, file upload and download these operations. Programmers love to use it to do automated testing, data capture can not be separated from it.

For example, you want to see what Baidu's home page looks like, directly in the terminal to knockcurl https://www.baidu.comThe web page source code can be stripped down in seconds. Much more convenient than using a browser, especially suitable for batch operation or writing scripts.

Why do you need to know curl for proxy IP?

When it comes to proxy IP, it's like wearing a cloak of invisibility for curl. Directly accessing a website is like running around naked, and it's easy for the target website to recognize your real IP. after using a proxy IP:

1. Hiding the real address → The website sees the IP of the proxy server.
2. Breaking through access restrictions → Some sites have access control based on IP
3. Distributed data collection → Rotate access with different IPs to avoid being blocked

For example, with ipipgo's proxy service, the curl command looks like this:
curl -x http://username:password@proxy.ipipgo.com:port http://target.com
Here username and password should be replaced with the account you registered with ipipgo, proxy.ipipgo.com is their home server address.

Hands-on teaching curl with proxies

Here's a whole configuration comparison table for the guys:

Focusing on the authentication thing, many newbies will be stuck here. ipipgo's agent needs account password authentication, remember to put theusername:password@This part is spliced into the address like this:
curl -x http://vip123:abc888@proxy.ipipgo.com:9023 http://example.com

Practical Tips and Tricks

You have to be careful when you come across these:

① Connection timeout → may be the proxy server is not stable, it is recommended to change ipipgo quality lines
② return 403 forbidden → The current IP has been hacked by the target website, quickly switch to a new IP.
③ At a snail's pace. → Check the geographic location of the proxy server and select a node close to the target site.

Here's a trick for you, use ipipgo's polling proxy feature to switch between different IPs automatically:
for ip in $(curl api.ipipgo.com/getips); do
  curl -x $ip http://target.com
done

QA time

Q: Will I be found by the website if I use a proxy IP?
A: Good quality proxies like ipipgo, with large and updated IP pools, are not easily recognized. But be careful not to use too hard to control the frequency of visits.

Q: What is the difference between a free agent and a paid agent?
A: Nine out of ten free agents are pits! Either the speed is slow or always dropped. Like ipipgo such professional service providers, not only fast, and after-sales technical support, engage in serious projects or have to use reliable.

Q: Is it safe to use a proxy at the command line?
A: focus on whether the proxy service provider is reliable. ipipgo full HTTPS encrypted transmission, account passwords are individually assigned, more secure than those wild agent.

Lastly, I'd like to say that you need to keep your eyes peeled when choosing a proxy service provider. Like ipipgo their home, the measured response speed can be up to 50ms or less, but also supports the amount of payment, especially friendly to individual developers. Engaged in data collection friends can try their dynamic residential IP, simulated real access to the effect of thief 6.