When using curl for network communication, let’s briefly learn about how to set headers.
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Using the Header Option with curl Command
To use header values in curl commands, set the header values after the -H or --header option as follows:
curl --header or -H "header option: header value"The method is very simple as above. After the header option you want to use, pass the value together using a colon (:).
? What values can be sent with the header option?
Typically, the header option is used to transmit values like the following:
- User-Agent // Information on the client (browser or application)
- Authorization // Token and credentials information for authentication
- Content-Type // MIME type information of the data being transmitted
- Accept // MIME type information of the content that the client can receive
- X-Requested-With // Information to identify AJAX requests
In addition to these, other standard HTTP headers like Cache-Control, Connection, Accept-Encoding, etc. can also be included.
Examples of Sending Headers with curl
Let’s make a few examples to understand in more detail.
@ Sending Multiple Header InformationWhen sending more than one piece of header information, use -H repeatedly.
$ curl -H "User-Agent: MyApp/1.0" -H "Authorization: Bearer YOUR_ACCESS_TOKEN" http://example.com
@ Sending Accept Type Information$ curl -H "Accept: application/json" http://example.com
@ Sending User-Agent Value$ curl -H "User-Agent: MyApp/1.0" http://example.com
So far, we’ve briefly learned how to use curl.