21 curl exercises

Reference:https://jvns.ca/blog/2019/08/27/curl-exercises/

These exercises are about understanding how to make different kinds of HTTP requests with curl. They’re a little repetitive on purpose. They exercise basically everything I do with curl.

To keep it simple, we’re going to make a lot of our requests to the same website: https://httpbin.org. httpbin is a service that accepts HTTP requests and then tells you what request you made.

  1. Request https://httpbin.org
  2. Request https://httpbin.org/anything. httpbin.org/anything will look at the request you made, parse it, and echo back to you what you requested. curl’s default is to make a GET request.
  3. Make a POST request to https://httpbin.org/anything
  4. Make a GET request to https://httpbin.org/anything, but this time add some query parameters (set value=panda).
  5. Request google’s robots.txt file (www.google.com/robots.txt)
  6. Make a GET request to https://httpbin.org/anything and set the header User-Agent: elephant.
  7. Make a DELETE request to https://httpbin.org/anything
  8. Request https://httpbin.org/anything and also get the response headers
  9. Make a POST request to https://httpbin.org/anything with the JSON body {"value": "panda"}
  10. Make the same POST request as the previous exercise, but set the Content-Type header to application/json (because POST requests need to have a content type that matches their body). Look at the json field in the response to see the difference from the previous one.
  11. Make a GET request to https://httpbin.org/anything and set the header Accept-Encoding: gzip (what happens? why?)
  12. Put a bunch of a JSON in a file and then make a POST request to https://httpbin.org/anything with the JSON in that file as the body
  13. Make a request to https://httpbin.org/image and set the header ‘Accept: image/png’. Save the output to a PNG file and open the file in an image viewer. Try the same thing with different Accept: headers.
  14. Make a PUT request to https://httpbin.org/anything
  15. Request https://httpbin.org/image/jpeg, save it to a file, and open that file in your image editor.
  16. Request https://www.twitter.com. You’ll get an empty response. Get curl to show you the response headers too, and try to figure out why the response was empty.
  17. Make any request to https://httpbin.org/anything and just set some nonsense headers (like panda: elephant)
  18. Request https://httpbin.org/status/404 and https://httpbin.org/status/200. Request them again and get curl to show the response headers.
  19. Request https://httpbin.org/anything and set a username and password (with -u username:password)
  20. Download the Twitter homepage (https://twitter.com) in Spanish by setting the Accept-Language: es-ES header.
  21. Omitted!
1~5
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2
3
4
5
curl httpbin.org
curl httpbin.org/anything
curl -X POST httpbin.org/anything
curl httpbin.org/anything -d value=panda # default:make a GET request
curl www.google.com/robots.txt
6~10
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2
3
4
5
6
curl httpbin.org/anything -H "User-Agent:elephant" # 6a
curl httpbin.org/anything -A "elephant" # 6b
curl httpbin.org/anything -X DELETE
curl -I httpbin.org/anything # -I: show the reference header
curl -X POST httpbin.org/anything -d '{"value":"panda"}' 
curl -X POST httpbin.org/anything -d '{"value":"panda"}' -H "Content-Type:application/json"
11~15
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2
3
4
5
curl httpbin.org/anything -H "Accept-Encoding:gzip"
curl -X POST -d @test.json httpbin.org/anything -H "Content-Type:application/json"
curl httpbin.org/image -H "Accept:image/png" --output test.png
curl httpbin.org/anything -X PUT
curl httpbin.org/image/jpeg --output test.jpeg
16~20
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2
3
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5
curl https://www.twitter.com -I # 303 Moved Permanently
curl httpbin.org/anything -H "panda:elephant"
curl httpbin.org/status/404 -I
curl httpbin.org/anything -u username:password 
curl https://twitter.com -H "Accept-Language:zh-CN" --output test.html