Widely accepted cross-platform software solution cURL is a popular command-line tool used for transferring data. One of the most significant advantages of Client URLs is support for numerous network protocols.
Other mainstream applications for cURL include sending API requests or using cURL with proxy. Both are highly effective, and in the case of proxy servers, cURL becomes an invaluable tool enabling many actions.
What is cURL?
Client URL is a command tool software with native support on the most popular operating systems. Those systems that don’t support cURL out of the box, like some Linux distributions, can easily install it. The primary purpose of cURL is data transfers over internet protocols.
The tool supports more than 20 protocols, such as HTTP, HTTPS, SOCKS, POP3, SMTP, IMAP, FTP, FTPS, Kerberos, POP3, SMTP, RTSP, LDAP, and many others. At the same time, the libcurl library supports SFTP, Telnet, TFTP, FTP uploading, HTTP form-based upload, HTTPS, proxy servers, and authentication through user-plus-password.
Most network people, researchers, and developers appreciate cURL because it is open source. In addition, the tool is compatible with IPv6 and can be used with over fifty programming languages.
Looking back on history
The small utilitarian tool with powerful functionalities was initially released in 1996. Its mid-nineties name was httpget, changed to urlget, and finally, it was named cURL. The tool came from Swedish software engineer Daniel Stenberg who attempted to create an automated way to fetch currency exchange rates for users on Internet Relay Chat.
Where to find cURL
Most users already have the Client URL tool on their computers. If you’re Windows 10 or 11 and a macOS user, you already have it. Most Linux distros also come natively with cURL, but you can easily install the software for those who don’t have it. Here is an example of how to get cURL on Ubuntu, probably the most common Linux distribution.
sudo apt install curl
From basic use to sending API requests
The original intent for cURL was to fetch currency rates. Instead, the tool evolved into command-line software capable of delivering and extracting information over various Internet protocols. So, for example, if you want to check the computer’s IP address and location quickly, you can type.
Another common primary use is to retrieve data from web pages. You can get the HTML of the page and study it on the console with
The same principle works with retrieving information from servers. Thanks to the included libcurl development library, the tool has many more available use cases.
One of the more frequent uses for cURL is sending API requests. Each request you sent has four integral parts.
An endpoint is an address or URL where you send the request. Then, you must choose the best HTTP method to send the package. For example, you can send GET, POST, PUT or DELETE. The GET command does what its name suggests. It retrieves a resource like a file or information from the server.
You can use POST to send information to the server, while PUT is commonly used for updating a record in a database or the contents of a file. So DELETE is pretty much self-explanatory.
To test the API with POST will take sending JSON arguments.
Curl –data “name=John&surname=Doe” http://www.samplepage.com
API requests also have headers where all the metadata, like content type and users, are stored. The body is the final piece of the puzzle containing the data you send. The body is associated with POST and PUT requests.
cURL with HTTP/HTTPS proxy
Proxy servers are a trendy tool that acts as an intermediate destination between your client and the destination server. Proxies have many use cases; their fundamental task is to hide IP addresses and act as a middleman when communicating with the server.
Outside of the primary use that increases the level of security and can enable accessing geo-specific services, proxies are used for more intense web scrapping and market research tasks. If you combine a proxy server with cURL, you can send or get information using internet protocols.
To use cURL with proxy, you must have the address, port, protocol, and authentication information. It would be best if you considered only paid proxy solutions, as free ones are often burdened with bloatware, and it is not uncommon to find malware on such services.
HTTP/HTTPS are the most widely used proxies. You can connect to the server with HTTP and subsequently create an HTTPS connection to the destination server. The command line is identical for HTTP and HTTPS proxies.
What can you do with cURL and proxy server
Gathering data is the essential use case for the cURL and proxy combo. With petabytes of information out there, you need a quality tool to get what you need efficiently. Web scraping is the method of retrieving data from websites for market research and various other reasons.
cURL is effective in retrieving such data. However, without a proxy, the unusual activity on the server might look suspicious. The proxy can help your requests look ordinary, and you can extract data without drawing attention.
Another potential use is going around geographic limitations. For example, if you change the IP address with a proxy, you can scrape data, monitor competitors, or test a specific region for new products.
Proxy servers also add a layer of security so that you can perform all your data transfers over internet protocols more conveniently with cURL.
Why is cURL a great tool?
There are numerous reasons people love to use cURL. The most significant advantages of this software include its portability, as it is compatible with most operating systems. You can use it for error logging and testing endpoints, and it could provide details of what was sent or received. You can also send API requests, and connecting with proxies opens new use cases.
cURL is a simple and light tool integral to most systems. Simultaneously, it is also a powerful software supporting most internet protocols and is suitable for automated tasks. The straightforward and easy-to-use sending and receiving information with cURL makes it useful for programmers, networking specialists, marketeers, web scrappers, and many others that need its specific features.