cURL with Proxy – A cURL is a popular open-source used for testing in web development. It also finds use in web scraping and a host of other industries requiring data transfer. This article will focus on how cURL is used with proxies for web scraping.
Web scraping has become a key data analysis process, as the internet contains more data than you’ll ever need. Accessing and leveraging the data is key, and cURL helps with that. Hence, let’s look at everything to know about cURL with proxy. In case you need an expanded technical tutorial, find more info in an in-depth guide.
What is cURL?
The term cURL stands for Client URL, a command line tool used for data exchange across devices and servers and other testing purposes. Being a command line tool, configuring cURL happens on the CLI (Command Line Interface).
Irrespective of the device you use – Windows, Mac, or Linux – you can use cURL for any task you want. Beyond its flexibility with device operating systems, cURL is also compatible with about 19 protocols, including HTTP, HTTPS, FTP, IMAP, SCP, SMB, etc.
As a scriptable command line tool, cURL can perform different complex tasks, which may be impossible for some of its alternatives.
The flexibility and ability to handle complex problems characteristic of cURL come from being powered by LibcURL. As a product of this library, cURL gets to perform various functions, including creating cookies, setting proxies, credentials authentication, testing APIs, downloading data, etc.
cURL always comes pre-installed on computers. However, in cases where yours has been inadvertently uninstalled, you can re-download it from the cURL website.
What are Proxy Servers?
Proxy servers intersect two main aspects of the internet – the clients and the servers. Proxies, by design, are the intermediary between users from the internet, so whenever a user makes an internet connection request, it first goes through whatever proxy they are connected to. Thanks to this, security, privacy and unrestricted access can be ensured.
Proxies achieve security, privacy, and access thanks to their fundamental functionality of changing the user’s IP address when a request is made. Normally, your computer’s IP address accompanies every internet request you make. Once you have a proxy set up, the request (and IP) goes to the proxy server, replacing your IP address with a new one.
Due to how proxies work, it’s impossible for servers to track the traffic from your device. The ability to hide IP addresses makes proxies essential tools for web scraping. Other than this, proxies also make it impossible for third parties to spy on your activities online – privacy.
Beyond enhancing privacy, security, and access, proxies also aid performance. For instance, proxies can cache data gotten from repeat requests so that new requests don’t have to be sent when you need data. This, however small, improves performance.
There are different types of proxies. Some are best for either personal or business purposes. Hence, the one you set up depends on your needs. So, you must do your due diligence to determine which one your project needs.
Irrespective of the proxy server type you need, it’s vital to learn how to use it with cURL.
How to Use cURL with Proxies?
cURLs are primarily designed to facilitate data exchange between devices and servers. Similarly, proxies make it difficult for servers to block IP addresses visiting. Hence, individually, these tools play important roles in web scraping. However, using cURL with proxy servers helps you enjoy better performance. Hence, the need to learn the various functionalities possible.
Setting Proxies in cURL with Command Line Argument
To initiate a proxy in your cURL, let’s go through the following command line steps:
You’ll get several lines of options as a response. But you’re looking for something that looks like this:
-x, –proxy [protocol://]host[:port]
Next, you should supply the proxy details with either –x or –proxy (they mean the same things. Though, beware of the case sensitivity of both).
curl -x “http://user:firstname.lastname@example.org:1234” “http://httpbin.org/ip”
curl –proxy “http://user:email@example.com:1234” “http://httpbin.org/ip”
Notice that the proxy URLs are wrapped in double quotes. This is the standard way to handle special characters present in the URL.
Note: It doesn’t matter if the ‘HTTP’ is present in the address. The URL will work, irrespective.
Using Environmental Variables
You can also set up your cURL with proxy by setting the environment variables https_proxy and http_proxy. These variable names indicate the protocol being targeted, HTTP or HTTPS. The environmental variables method, however, only works when you use a macOS or a Linux device.
The first step is to set the variables to their respective proxy addresses. Do the following in the shell terminal:
Subsequently, run the cURL
If there is an error, ignore them by using –k
Note that these commands work system-wide. To change that, unset the variables.
There are other ways to use cURL with proxies, but these two will get you going immediately. Using cURL with proxy servers is also a great combination for your web scraping activities and is highly recommended. Do further research into the LibcURL library to see how you can improve your web scraping game.