Curl 1020 error when trying to scrape page using bash script

Web scraping is a useful technique for extracting data from websites to use programmatically. However, you may occasionally run into errors that prevent your scraper from accessing site content.

One common error is cURL error 1020, which indicates that your scraper cannot connect to the target server or page. In this guide, we’ll explore the causes of error 1020 when web scraping and provide fixes to resolve connection issues.

What Causes cURL Error 1020?

cURL error 1020 occurs when cURL, the data transfer library used by many web scrapers, fails to connect to the target web page or server. Some potential reasons you may get this error include:

So in summary, error 1020 suggests your scraper cannot talk to the website - whether due to active blocking, technical issues, or missing credentials.

5 Ways to Fix cURL Error 1020

Luckily, there are a few approaches you can take to resolve error 1020:

1. Check the URL

Double check that the URL you are trying to scrape is valid. For example, if scraping a page on example.com:

curl https://www.example.com/page-to-scrape 

Correct any typos or protocol issues in the URL.

2. Use a Browser User Agent

Websites may detect and block common scraping user agents like curl. Specify a browser's user agent to appear like a normal visitor:

curl -A "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36" https://www.example.com/page-to-scrape

3. Authenticate with Cookies

If the site needs a login, you can pass saved cookies to authenticate:

curl --cookie "session_id=1234; userId=5678" https://www.example.com/page-to-scrape  

4. Retry on Failure

For intermittent issues, retry the request 2-3 times:

RETRY=0
MAX=3

while [ $RETRY -lt $MAX ]; do
  curl https://example.com/page &> /dev/null
  if [ $? -eq 0 ]; then
    break
  fi  
  let RETRY=RETRY+1 
done

This retries up to 3 times, waiting between each attempt.

5. Use a Proxy or VPN

If the site is actively blocking your server's IP range, you can route requests through a proxy or VPN to mask your origin.

Proxies and VPNs provide an alternate IP to connect from. Just specify your proxy URL in cURL:

curl --proxy http://1234.56.78.90:8080 https://www.example.com/page-to-scrape

Wrap Up

cURL error 1020 makes web scraping fail when the client cannot communicate with the website properly. Fixes like using browser agents, cookies, and proxies can help circumvent blocks to resolve the issue.

Carefully check for typos, authentication requirements, or usage limits when running into 1020 errors. With the right approach, you can troubleshoot connection issues and get your scraper working again.