Curl Web Capture: A Guide to Efficient Capture at the Command Line

When white meets curl: don't let IP blocking be your roadblock

When I first learned to crawl, I always wondered why I was always kicked offline by websites. Until one day, I realized that using my own broadband connection to capture data is like wearing a fluorescent suit to be a spy - people will recognize you at a glance! This time you need to proxy IP this "disguise artifact", so that curl command each request to change a vest.

curl basic operation: do not rush on the proxy, first learn to walk

Let's start with a bare-bones version of the curl command:

curl https://example.com

It's like registering an account repeatedly with your own cell phone number...who do you block if not you? Plus-vParameters can see the detailed communication process, it is recommended that novices are equipped with this "lens":

curl -v https://example.com

Vesting curl: three ways to wear proxy IPs

Here's a recommendation for your own home useipipgo proxy service, with good stability in real-world tests. Three configuration options to choose from:

Real-world examples: tips for staying alive when catching e-commerce prices

Last week to help a friend to catch a certain platform product information, do not use the proxy, if you can not hold up to 20 requests. Then I used ipipgo's dynamic residential IP pool and configured it like this:

for i in {1..100}; do
  curl -x $(shuf -n 1 ip ipgo_ip.list) "https://target.com/product/$i"
done

here areipipgo_ip.listIt's a list of real-time IPs obtained from their backend, randomly selected with the shuf command, much more stable than a single IP.

Guide to avoiding pitfalls: the wrong agent, all the effort is wasted!

Common rollover sites:

• ❌ Write the colon in the proxy address as a full-width character
• ❌ 忘记在密码里转义特殊字符（比如@要改成%40）
• ❌ Accessing http sites with highly anonymized IPs (pure waste of money)

It is recommended that testing be done by visiting thehttps://ip.ipipgo.io/checkip, confirming whether the proxy is in effect.

Troubleshooting QA

Q：What should I do if my proxy IP suddenly fails?
A: 80% encountered IP pool pollution, quickly contact ipipgo customer service for a new pool. They have an "Emergency Replacement" feature that works well.

Q: Slow as a snail to crawl?
A: Try these three axes:
1. Switching ipipgo's business line nodes
2. Increase the -connect-timeout parameter of curl.
3. Don't use free agents! Don't use free proxies!

Q: How do I break the CAPTCHA when I encounter it?
A: Reduce the frequency of requests, then change ipipgo's real-life operating IP. if that doesn't work, you'll have to go to image recognition, but that's another story...

Upgrading your equipment: ipipgo's one-trick pony

Their 'smart routing' feature is kind of interesting in that it automatically selects the fastest route. It works like this in curl:

curl --proxy-anyauth --proxy "http://smart.ipipgo.io:8888" -U "username:password" destination URL

This -proxy-anyauth parameter enables curl to automatically adapt to various authentication methods for lazy players.

Lastly, I would like to point out that proxy IPs are not a panacea, and User-Agent rotation and request intervals are the way to go. Next time you have the opportunity to nag how to use curl to play with flowers!