This tutorial will teach you how to send data through a proxy server using the command line tool cURL. In between a client and a destination server, a proxy server mediates. Each command that the client wishes to run can be forwarded to the proxy, which will then carry it out and deliver the outcome to the client.
When a target service, for example, employs geolocalization to limit the data provided or altogether restricts access to users in particular areas, we might want to accomplish this. This method is used on many international shopping websites to show pricing in local currencies instead of dollars, such euros. If we went to the site directly, the information would be in the incorrect currency. We can retrieve the data we need based on the proxy’s locale by utilising a proxy.
You’ll discover many cURL proxy usage techniques.
This detailed tutorial will show you how to utilise curl, also known as cURL, with proxy servers. It covers every angle, starting with installation and ending with an explanation of the several proxy-setting options.
No specific proxy service was our focus. As a result, this guide ought to function with every proxy server. You only need to be aware of the server information and passwords.
Given the nature of this lesson, readers should have a fundamental understanding of what a proxy is.
For people just getting started with web scraping, it would be quite fascinating and helpful.
Describe cURL
A command-line tool for using the url to send and receive data is called cURL. Let’s see the most basic application of curl. Open a terminal or command prompt, enter the following command, and then click OK:
curl https://www.google.com
With this, the HTML of the page will be obtained and printed on the console.
curl Google -I, https://www.google.com
This will print the information from the document.
SSL/TLS 1.1 200 OK
HTML content with the encoding ISO-8859-1
One of our earlier articles also provides a definition of cURL. If you want to find out how it came to be such a valuable asset, we suggest reading it.
Describe a proxy
Between the client and server sides, proxy servers function as an intermediary. In order to hide the user’s identity, a proxy server is used to relay requests made by users to the server. The proxy server processes the data and transmits it back to the client after receiving the server’s response.
In order to access geo-restricted content or scrape information from servers that forbid automated requests from bots, proxy servers are used. Users can also use proxies to browse the internet anonymously for security reasons.
How cURL Operates
The syntax that cURL employs is as follows:
[option] [url] curl
Commands that instruct cURL what to perform are referred to as [option]. For instance, -x instructs cURL that a proxy server will be used to establish the connection. Many commands have alternate names; for example, you can type proxy in place of -x. Some arguments may be used after the URL, such as -v, which instructs cURL to show the connection details. Although they are not required by the syntax, options are what you’ll use the majority of the time.
The domain you want to communicate with is indicated by [url].
Obtaining cURL
You already have cURL installed on Windows 10 or 11, macOS, and the majority of Linux systems. You can install it for Linux distributions that don’t already have this potent tool. Ubuntu is the most widely used Linux, and with this command in the Terminal, you can get cURL.
cur install sudo
cURL and HTTP/HTTPS proxy usage
You and the destination server are connected through a proxy server. It can be used in conjunction with cURL to retrieve or transfer data through internet protocols. You will need a proxy server’s IP, port, protocol, and, for high-quality proxies, a username and password for authentication in order to connect with it.
Most people use HTTP/HTTPS proxies. Most of the time, providers will let you establish an HTTPS connection with the destination website first, then use HTTP to connect to the proxy. For both HTTP and HTTPS proxy servers, your connection command will appear the same. An illustration of a command for utilising cURL with a proxy is shown below:
Requisites for connecting to a proxy
Regardless of the proxy service you use, you will require the following details to use a:
- proxy server information
- port
- protocol
- username (if authentication is necessary)
- password (if authentication is necessary)
We’ll assume for the purposes of this lesson that the proxy server’s IP address is 127.0.0.1, its port is 1234, the user’s name is user, and its password is pwd. We’ll examine a number of examples involving different protocols.
NOTE: If you are using NTLM authentication on your network, you can execute curl with the -proxy-ntlm switch. In a similar vein, digest authentication can be performed using -proxy-digest. Run curl -help to view all of the options that are available. Examples of situations where a username and password must be entered are provided in this tutorial.
The first curl proxy situation, which also happens to be the most typical one, will be covered in the next section. It involves an HTTP and HTTPS proxy.
HTTP versus HTTPS
When choosing between HTTP and HTTPS for safe data collecting, HTTPS is the better choice both for curl and generally speaking. The “S” stands for Secure since it uses Transport Layer Security (TLS) protocols for improved end-to-end encryption.
In addition to securing the confidentiality and integrity of the data being transported, HTTPS aims to authenticate the destination website. Therefore, HTTPS is more suited for covertly gathering or sending sensitive data. While HTTP is more appropriate for gathering data at scale or for in-depth market research.
The information above can be used by each company to determine which protocol, both generally and when employing curl, best meets their needs.
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