What Is cURL and How to Use It with a Proxy?

 

cURL stands for client URL, and it is a command line tool to send and receive data using an URL. This text-based tool runs in the terminal or command prompt of your system. Besides using it for proxy support, HTTP posts, and user authentication, many people use it to scrape web pages.

cURL proxy is helpful in web scraping, but you need to properly install and configure it. Proxyway tells you how to install and configure the cURL proxy in detail. Let’s take a closer look at what cURL is and how to use it with a proxy.

What Is cURL?

As we have already mentioned, cURL is a command line tool that allows users to send and receive data using URLs. cURL started more than two decades ago and is still a popular way of scraping web data.

It supports more than 25 protocols, including HTTP, HTTPS, FTP, and SFTP. This free, open-source tool works on various operating systems like Linux, Mac, and Windows. If your system doesn’t have cURL out of the box, you need to install it before using it. We will get to that in a minute.

What Is a Proxy?

Proxy servers work as an intermediary between the client and server sides. When a user requests something from the server, the request gets redirected through a proxy server to mask the identity of the user. When the response from the server gets back, the proxy server processes the data and sends it back to the client.

As a result, proxy servers help access geo-restricted content or scrape data from servers that prevent automated requests from bots. Proxies also enable users to hide their identity while browsing the internet for security reasons.

How to Install cURL?

Before you start using cURL with proxies, you need to install it on your system. If you use macOS, you need to follow these steps to install cURL.

Open the terminal and run the following command.

  • $ /bin/bash -c “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)”

If it requires any password, you can simply enter the MacBook password.

After that, run the following command.

  • $ echo ‘eval “$(/opt/homebrew/bin/brew shellenv)” ‘ >> ~/ .zprofile

And run the final command below.

  • $ brew install curl

If you use Windows or Linux machines, you need to download and install cURL from the official download link. In some modern devices, you can also install cURL by running the following command.

  • sudo apt install curl

How to Use cURL with Proxy Servers?

Once cURL is installed on the machine, you can now use it with proxy servers. Let’s see how you can do it.

You will need the proxy server address, port number, and protocol type to connect with the proxies. Let’s say the proxy address is 127.0.0.1, and the port number is 80. The following syntax will be the command to connect to a server using proxies.

  • curl – -proxy proxyaddress:port https://anywebsite.com

You can also write it the following way.

  • curl – -proxy 127.0.01:80 https://anywebsite.com

This command will make sure the request from your device will go to anywebsite.com via a proxy. And you can check the IP address too. But the scenario changes when the proxy server requires authentication. For such cases, you can use the following syntax in the terminal or command prompt.

  • curl – -proxy 127.0.0.1:80 -U “username:password” https://anywebsite.com

How to Check a Proxy Server with cURL?

You can check a proxy server by running the following command in the terminal.

  • curl – -x 127.0.0.1:80 https://anywebsite.com

You can also use the word proxy instead of x and the domain of the website instead of the proxy address.

How to Configure cURL to Always Use Proxy?

If you want cURL to use a proxy all the time, you can create a curl config file (.curlrc). You can create the file using the following command.

  • cd ~
  • nano .curlrc

Once the file is created, you need to add the proxy to the file as below.

  • proxy=”http://username:password@127.0.01:80”

Save the file, and you’re done. Next time you run cURL, the system will automatically find the .curlrc file and load the proxy configurations you set previously. You can create such files to configure cURL to always use the proxy.

Conclusion

cURL is a developer tool to send and receive data using URLs. This command line tool is used with proxies to debug network requests. As it supports a lot of protocols, using cURL with HTTP or HTTPS is very common. Proxyway shows how to use cURL proxy in detail so that you can install it on your machine and run cURL with proxies.

It can also be used with SOCKS, POP3, SMTP, and IMAP proxies. Most modern operating systems come with cURL installed. But if you don’t have one, install it following the method above and curl some proxies.