When it comes to web development, there is nothing more resourceful than being on the loop with premium and more effective tools in the market. One such tool is cURL. You might have heard about cURL before or not, but whichever the case, if you read through this document; you will get an in-depth understanding of cURL is, its use, and its array of benefits.
What is CURL and What Does It Stand For?
Curl is object-oriented programing software that is used to transfer data through a vast array of Internet Protocols for a given URL. It is a command line utility that permits the transfer of files within the URL syntax. Curl is basically a client-side program which boasts commands that are designed in a way that they work to check connectivity to the URLs and facilitate data transfer. Curl’s creator, Daniel Stenberg, defined it as a library that permits you to connect and interact with different servers with a number of protocols.
In the word cURL; ‘c’ stands for a client, while ‘URL’ indicates that curl works with URLs. This software supports various protocols including FTP, HTTPS, HTTPS, TELNET and SMT which makes it an ideal candidate for interacting with APIs.
Curl can work on any platform and on any hardware that exists today, but while some systems come pre-installed with it, some need manual installation for it to function.
When to use cURL?
Since curl supports connection to remote systems over HTTP, HTTPS, TELNET and a vast array of other protocols, it is used when a script wants to access information from a remote system just like it was a local file/data stream. This is critical for developers who would wish to acquire data from a remote system and present it as they had it locally. Curl can be used in a terminal or command prompt, but you need to ensure that it is installed in the system you are using before you try to use it.
What is cURL PHP?
CURL PHP is a module that makes it possible for PHP programs to gain access to curl functions within PHP. For example, curl exec is a command line in PHP that makes it easier and quicker to call GET/POST requests, as well as receive responses from other servers like JSON and download files.
There are various use-cases for Curl such as proxy support, FT upload, HTTP post and SSL connections among others. Below are some Curl examples, along with a detailed explanation of what they do.
1. Return the HTTP Headers of a URL Only
Curl -I https:// www.keycdn.com/
The -I option is used to instruct Curl to only fetch the HTTP header form a particular page or resource.
2. Making HTTP GET Request
Curl https:// www.keycdn.com/
This shows a basic curl command calling a GET request for a website URL.
3. To Bestow an Additional HTTP Header
The curl command can also be used to add a new HTTP Header to GET requests. All you need s to add the – H option followed by the header name and value in enclosed quotes.
curl -H "X-Header: Value" https://www.keycdn.com/
4. Continue a Download
Curl command can also be used to resume a download that was purposely stopped or interrupted. You simply add the -c to the Curl command in question and the system will resume downloading an item from where it stopped.
curl -C - -O https://cdn.keycdn.com/img/cdn-stats.png
cURL APIs on RapidAPI
RapidAPI allows developers to access Curl APIs. They need to install curl if it is not pre-installed and unirest PHP 5.4+ either with a composer or from Github. Then they can use Unirest to create requests in PHP.