Response Handling using cURL

Response Header

When making an API request, it's essential to inspect the response header to gather information about the request. For example, we might want to know the server type, content type, or cache control directives. To view the response header using cURL, run the following command:

curl -s -I -X GET https://jsonplaceholder.typicode.com/todos/1

The -s option tells cURL to be silent and not display the progress meter, while the -I option instructs cURL to show only the headers. The GET request is made to the specified URL, which returns a JSON response.

Response Code

Another crucial aspect of response handling is examining the response code, also known as the HTTP status code. This code indicates whether the request was successful or not. To view the response code using cURL, run the following command:

curl -s -o /dev/null -w "%{http_code}\n" -X GET https://jsonplaceholder.typicode.com/todos/1

The -o option tells cURL to write the output to a file (in this case, /dev/null, which discards the output), while the -w option specifies the format of the output. The "%{http_code}\n" format displays only the HTTP status code.

Response Body

Finally, we might want to inspect the response body, which contains the actual data returned by the API or web server. To view the response body using cURL, run the following command:

curl -s -H "Content-Type: application/json" -X GET https://jsonplaceholder.typicode.com/todos/1

The -H option sets a custom header (in this case, Content-Type) to specify that you want to receive JSON data. The response body is then displayed in a human-readable format.

In conclusion, understanding how to handle responses from APIs and web servers using cURL is an essential skill for any developer. By mastering the basics of response handling, we can troubleshoot issues, inspect API responses, and build more robust applications.