curl POST Request: Sending Data from the Command Line Tutorial

Teach you how to use curl to send POST request and solve the problem of IP blocking.

You code the old iron should have encountered this situation: use curl test interface, suddenly found that the server does not take care of you. At this time, it is likely that your real IP has been pulled by the other side of the black! Today we will teach you how to use proxy IP with curl to send POST requests, and incidentally solve this headache.

The basic posture of curl sending POST.

First of all, let's review the basic operation of curl sending POST (don't worry, there are agent tricks later):

The simplest form submission:

curl -X POST -d "username=Zhang San&password=123456" http://api.example.com/login

Pass JSON data to add request headers:

curl -X POST -H "Content-Type: application/json" -d '{"query": "weather"}' http://api.example.com/search

Note that there is a pitfall here: many newbies forget to add the-Hparameter specifies the data type, and as a result, the server is dead set on not recognizing your request.

[Emphasis added] Put a proxy vest on curl.

When it turns out that the request was rejected, it's time to sacrifice the magic weapon of proxy IP. Here we recommend the use ofipipgoTheir proxy service specializes in high stash dynamic IPs, which have been tested to bypass most blocking tactics.

The proxy parameter format looks like this:

curl -x http://用户名:密码@proxy:port -X POST ...

As a real-life example: suppose that fromipipgoThe backend gets an HTTP proxy that isproxy.ipipgo.com:8000The account password is vip123 and the full request should be written as:

curl -x http://vip123:vip123@proxy.ipipgo.com:8000 -X POST -d "content=test" http://api.example.com/comment

[Guide to Avoiding Pitfalls] Common Rollover Scene

A few common problems encountered by newbies:

1. What should I do if I can't connect to the agent?

First, check that the proxy address is not misspelled, and in particular, be careful not to write thehttpsacting ashttpUse. Use.ipipgoIf you do, their tech support is online 24 hours a day, so you can just ask customer service for a test command.

2. Return 407 Agent Authentication Error

This is most likely a case of a wrong account password, or you don't have enough balance in your account.ipipgoThere's aKey Managementfunction, it is recommended to change your password regularly for security.

3. What if the request slows down?

Try cutting toipipgoThe exclusive high-speed channel, their BGP line measured latency can be controlled within 200ms, much more stable than the free agent.

QA time (a must for newbies)

Q: Do I have to write the proxy parameters every time?

A: You can set environment variables to save time:

export http_proxy=http://vip123:vip123@proxy.ipipgo.com:8000
export https_proxy=$http_proxy

Q: How do I know if the proxy is active?

A: Test the IP address with this command first:

curl -x proxy address http://ip.ipipgo.com/

Q: Does ipipgo's proxy support HTTPS?

A: It is fully supported! Their proxy service has SSL encryption enabled by default, so you don't have to worry about sensitive data being intercepted by intermediaries.

A final piece of cold knowledge: usingipipgoThe rotating proxy function can be set to automatically change IP every 5 minutes, with crontab timed tasks, a perfect solution to the need for long-term operation of the data collection needs. I have personally tested this feature, and it has been running for 72 hours without dropping, so it's stable as a batch!