How to do a PUT request with cURL?

When using cURL to perform PUT requests, it is commonly done to update the state or content of resources on the server. cURL is a highly versatile command-line tool that can be used to send various types of HTTP requests. Below are detailed steps and examples on how to use cURL to execute PUT requests:

1. Basic PUT Request

If you only need to send a basic PUT request to the server, you can use the following command:

bash
curl -X PUT [URL]

Here, -X PUT specifies the request type as PUT.

2. Including Data in a PUT Request

It is common to include data when sending a PUT request, which can be specified using the --data or -d parameter. For example, if you need to update user information, you can do the following:

bash
curl -X PUT -H "Content-Type: application/json" -d '{"name": "Alice", "email": "alice@example.com"}' [URL]

Here, -H "Content-Type: application/json" specifies that JSON-formatted data is being sent. The -d parameter follows the data payload you want to transmit.

3. Using a File as the Data Source for a PUT Request

If the data you want to send is large or you already have a file containing the data, you can use --data-binary with the file to ensure the data is sent exactly as it is, without modification or transformation by cURL. For example:

bash
curl -X PUT -H "Content-Type: application/json" --data-binary @data.json [URL]

Here, @data.json indicates that the data originates from the local data.json file.

4. Handling Authenticated PUT Requests

If the API requires authentication, such as basic authentication, you can use the -u parameter:

bash
curl -u username:password -X PUT -H "Content-Type: application/json" -d '{"name": "Alice"}' [URL]

5. Tracking Response Headers and Status Codes

To debug or verify the execution of the request, you might want to view response headers or status codes. You can add -i or -v to access this information:

bash
curl -i -X PUT -H "Content-Type: application/json" -d '{"name": "Alice", "email": "alice@example.com"}' [URL]

-i includes HTTP response headers in the output, while -v (verbose mode) provides detailed request and response headers along with error debugging.

The above steps and command examples should help you use cURL to execute PUT requests. In practical applications, adjust these commands according to the specific requirements of the API to meet your needs.