cURL POST Request: Proxy IP for Form Submission

Hands-on with a proxy IP to send POST forms

Recently found that many partners in the use of cURL to do data submission often hit the wall, especially the need to batch processing form scenarios. Today we will take our most commonly used ipipgo proxy service as an example to teach you how to easily bypass the various restrictions.

Let's figure out a few key points first

Why do I need a proxy IP?For example, like going to the supermarket checkout line, if you always use the same cashier, the clerk may remember your face. Web servers will also remember the frequent access to the IP, this time the need for proxy services such as ipipgo to help you "disguise".

Here's a comparison table to visualize it better:

Real-world configuration steps

First make sure that the computer is installed on the latest version of cURL, this go to the official website under the line. Let's take the registration form submission as an example, assuming that you want to submit the user name, email two fields.

curl -x http://username:password@gateway.ipipgo.com:9020
-d "username=testuser&email=contact@example.com"
-H "Content-Type: application/x-www-form-urlencoded"
-X POST https://target-site.com/submit

Parameter Description:
– -x Specify the proxy server (note that the address of ipipgo should be filled in with your own account)
– -d followed by the data to be submitted
– -H Set the request header, which is required for form submissions.
- Replace the last URL with the actual address to be submitted

Guide to avoiding the pit

Frequently asked questions on demining:
1. Why does it return a 403 error?
- Check if the proxy IP is in effect (test with the command without proxy first)
- Verify that form field names match
- Does ipipgo's package expire

2. How can I improve my success rate?
- Put a delay in the code, don't make the server think it's a bot
- Dynamic residential proxy using ipipgo, more realistic than regular server room IPs
- Clean up local cookies regularly

3. Successful data submission but not receiving feedback?
- Check the anti-spam mechanism of the target website
- Try replacing the User-Agent header
- Testing with different geographic nodes with ipipgo

advanced skill

When batch operations are needed, they can be automated with shell scripts. Here is a sample template:

! /bin/bash
for i in {1..50}
do
   curl -x http://user$(date +%s)@gateway.ipipgo.com:9020
   -d "username=user$i&email=user$i@domain.com"
   --retry 2
   --retry-delay 5
   -H "Content-Type: application/x-www-form-urlencoded"
   -X POST https://target-site.com/submit
   sleep $((RANDOM%7+3))
sleep $((RANDOM%7+3))

This script implements it:
- Automatically generate time-stamped forensic information (be careful to change to your own ipipgo account)
- Delay of 3-10 seconds at random intervals
- Failure auto-retry mechanism

QA First Aid Kit

Q: Is it okay to use a free proxy?
A: Short-term testing is fine, but for long-term use it is recommended to choose ipipgo's commercial package. Free proxies generally have slow response, unstable connection, data leakage risk, especially to do form submission of such sensitive operations.

Q: What if it's too much trouble to enter my password every time?
A: Two solutions:
1. Use the API provided by ipipgo to dynamically obtain a proxy (recommended)
2. Write the authentication information to the environment variable:

export http_proxy="http://user:pass@gateway.ipipgo.com:9020"

Q: How do I break the CAPTCHA used on the website?
A: This is not something that can be solved by the agent, you need to work with the coding platform. However, using ipipgo's high stash of agents can reduce the probability of triggering CAPTCHA, and it is recommended to choose theirDynamic Residential Agent PackageThe

As a final reminder, do automated submissions to comply with the site's terms of service. Reasonable use of proxy technology, ipipgo's intelligent routing system can help us to efficiently complete the task within the scope of compliance. If you encounter technical problems, their 24/7 technical support response is quite fast, and I've personally tested that there are people who respond to work orders sent at two o'clock in the middle of the night.