What is cURL and how to send cURL GET requests?

Understanding HTTP requests and APIs is crucial for automating tasks and troubleshooting especially. When I need to send an HTTP request quickly, I always find using cURL.

cURL (Client URL) is a kind of technology that you can use to make a connection between a web server and your device by writing commands in the command line. By typing the server URL and the data you want to send it, cURL gives you various possibilities to perform different types of the requests, which are complementary to the tools like Postman and Insomnia which run from the terminal.

This is because in this article, I will be teaching what the cURL command is, how it works, and give some typical examples and use annotations.

cURL (Client URL, pronounced "curl") is a software that allows you to quickly and directly exchange data between your device and the server over the command line through the terminal. In cURL, you state the server URL (problematic internet server address) and the data you want to send.

Postman and Insomnia have a user-friendly interface for making different requests to URLs, while cURL does the same thing directly right from the terminal. They can run on Linux, Mac, or Windows.

The primary cURL command is: curl http://example.com. In this example, it can return the HTML source code of the webpage as you're asking it to fetch the URL.

cURL makes use of the libcURL library, offering support for various transfer protocols including HTTPS, SMTP, and FTP. It also allows you to handle cookies, set proxies, and include authentication credentials when you are requesting data.

cURL can be used for many different purposes such as testing APIs, downloading data, checking websites, and following redirects, all of this is done from the command line.

Now just understand how you can use cURL in your system. Most operating systems already have curl installed. If you can’t find it simply go to (https://curl.se/download.html) and install. We also show you how to use cURL in Postman too.

To check if your system already has cURL installed, open your terminal 
and type curl --version. If it's installed, then you'll see the version 
number and which features are enabled.

Running curl Examples in Terminal

Since most computers come with curl pre-installed, you can easily run a sample API request by copying code from our documentation and pasting it directly into your terminal.

Here’s an example of cURL get command:

Running curl Examples in Postman

If you're not comfortable using curl in the terminal or just prefer graphical user interface (GUI) apps, Postman is a great option. You can even import curl commands into Postman. Just copy any curl command and paste them into Postman.

Step 1: Import curl

Open the Import dialog window by clicking the Import button on the Postman toolbar.

Step 2: Send the Request

Once the curl command is imported, a new Request tab will appear in the main Postman window. This Request will already include the URL, headers, query parameters, request body, and other details from the curl command. All you need to do is click the "Send" button. (You will need to enter your API key to get a result).

A GET request is a way for your browser to ask a server for information from a specific web page. For instance, when you enter a URL in your browser and hit enter, it sends a GET request to the server to fetch the HTML code for that page.

Other types of HTTP requests can also get HTML from a server, but they have different purposes. For example, a POST request is used to send data to a server, like when you log in with your username and password. Although you might see a web page after logging in, the POST request's main job was to send your information to the server.

In contrast, a GET request doesn’t send any data; it simply asks for a page or resources like images. Here’s a basic code of a cURL GET request:

Now that we have the basics down, let’s look at how to send a GET request using cURL in the terminal. We’ll use https://elightwalk.com for our examples, as it's a straightforward HTTP request and response service. Here’s what we’ll cover:

1. Simple cURL GET Requests
2. Sending a GET Request with Parameters
3. Retrieving GET HTTP Headers
4. Receiving Responses in JSON Format
5. Following Redirects
6. Sending Cookies with a GET Request

These steps will help you effectively use cURL to send GET requests and handle various scenarios.

To send a basic GET request to the Elightwalk website, simply use the following command:

You can include parameters in your GET request. Here’s how to send additional data using -G and -d:

Use the -i option to get the HTTP headers together with the response body:

To request the response in JSON format, use the -H option:

If the URL redirects to another location, use the -L option to follow the redirect:

To send cookies along with your GET request, use the -b option:

We hope this guide has helped you understand the basics of cURL GET requests. Like any skill, practice is essential. We recommend spending some time sending requests to become comfortable with cURL.

If you're interested in learning how to make cURL requests in Magento 2, check out our blog post:

Also read: How to Make cURL Request in Magento 2

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