Introduction

Web data extraction has become one of the most crucial concepts in business. Therefore, you need to understand how cURL, a command-line library for making HTTP requests, works. This powerful tool is designed to interact with APIs to facilitate data fetching from remote servers. 

cURL GET requests act as an intermediary between your code and the website you want to scrape its data. In other words, they play a significant role in optimizing data collection. Subsequently, this article will discuss cURL GET requests, how they work, and how to optimize them with NetNut proxies.

Let’s dive in!

What is cURL?What is cURL

cURL is a command line tool that allows you to transfer data with URLs. Web developers can leverage cURL to initiate requests and interact with several resources, like websites and APIs, directly from the scripts or command line. Features like ease of use and flexibility make cURL a crucial component in modern web development. 

In addition, cURL supports a wide range of protocols like FTPS, FTP, HTTPS, and HTTP, which makes it an incredible option for activities such as API integration, file transfers, and data retrieval. Also known as Client URL, it supports cookie handling, proxies, user authentication, and SSL connections. Therefore, cURL can handle secure web communications.

Although cURL commands are quite straightforward, it has the capacity to handle various complex operations and request types. Therefore, this makes it extremely useful for effective communication between apps and remote servers. 

What is a GET Request?

The GET request is an HTTP method that allows you to extract data from a target resource on a web server. Let us consider a simple example of the GET request: you want to check the top 10 movies on IMDB. The first step is to open your browser and input your query in the search bar and this triggers a GET request. Subsequently, your browser sends a GET request to IMDB, and the response determines what will be displayed on your screen. 

In simpler terms, the function of the GET request is to ask the target server for a specified resource, which can be a document, an image, video, or HTML page. cURL GET request is simple and easy to use because of how it works- it does not alter the specified resource or the state of the server. The main function of the cURL GET request is to retrieve data so it is read-only. Therefore, it does not make changes to the target server or send data.

A feature of GET requests is that it supports appending key-value pairs to the URL. Also known as query parameters, they allow you to indicate the specific action you want to implement. When you enter a search query on Google, for example, it is transmitted as a series of parameters via the cURL GET request to the search engine server. Subsequently, the server processes the parameters, extracts the associated results, and sends back a response, which is displayed in your web browser. 

One limitation of using the cURL GET request is that it does not encrypt the parameters it sends to the server. As a result, it is not suitable for sending confidential or sensitive information because the parameters are visible to anyone who can see the URL.

Benefits of cURL GET Requests 

Using cURL GET requests has some benefits, especially for web scraping. Here are some reasons why it is an excellent choice for some of your activities:

Lightweight

One of the benefits of using cURL GET Requests is that it is lightweight. Since it is a command-line tool, it is quite resource-efficient. Therefore, if you want to write codes for a program but you are working with a device with limited resources, cURL GET Requests becomes an excellent choice.

Simple to use

Another advantage of using cURL GET Requests is that it is simple to use. Therefore, beginners, as well as experts, can use this command-line tool for creating programs with ease. In addition, it has a fairly gentle learning curve compared to many other dedicated scraping libraries. 

Direct control

A significant advantage of using the cURL GET Requests is that it provides direct control over the request. Subsequently, using this command line allows you to specify headers, handle redirects directly, indicate user agents, and increase flexibility for optimized customization. 

Versatility

cURL GET Requests stands out for its versatility, which makes it useful for many processes like building a web scraper. This command line supports a wide range of protocols, including HTTP, SFTP, and FTP.

Integration with scripting

Lastly, cURL GET Requests can be integrated into automation workflows or shell scripts from Python or Bash. Subsequently, you can leverage this command line to automate repetitive web scraping activities.

How to send GET requests with cURLHow to send GET requests with cURL

In this section, we shall examine how to send a cURL GET request via a terminal. The steps include:

Step 1: Simple cURL GET requests

Instead of using 

–request, you can send a GET request if it is the default method via this code: 

curl http://www.example.com.org/get

Step 2: Send a GET request with parameters

A GET request with parameters allows you to send extra data to the server using the URL of the request. Subsequently, cURL offers two alternatives to achieve this, and they are, -d, -G. 

However, if you use –d only, the request will be perceived as a POST request. In addition, the –d function will be ignored if you use the -X option with GET value. Therefore, you must use –G with –d to send a GET request with parameters.

url -G -d “param1=value1” -d “param2=value2” http://www.example.com/get

For this command, “param1” and “param2” are the keys while their respective values are represented as “value1” and “value 2.” Bear in mind that you can use the –d option several times to send different parameters.

An alternative way to write the above code is to include the GET parameters in the URL, as shown below:

curl ‘http://www.example.com/get?param1=value1&param2=value2’

Step 3: Extract GET HTTP headers

You can extract HTTP headers when sending a request. These headers are useful for exchanging extra information between the server and client. Use the –i or –include options in the cURL GET command to extract the HTTP headers with the response body.

curl -i http://www.example.com/headers

The above command line extracts the HTTP response headers, including content type, server, content length, and date. Subsequently, these parameters offer critical information regarding the specifics and nature of the response data. 

Alternatively, the long parameter for retrieving the response headers is –head with this line of code:

curl –head http://www.example.com/headers

Step 4: Retrieve responses in JSON format

While there are various formats for data exchange in the web development and data scraping ecosystem, JSON has quickly become a standard. Therefore, it is crucial to request data in JSON format while using cURL GET request. Subsequently, you can instruct cURL to accept the response in JSON format by using the -H option followed by “Accept: application/json”:

curl -H “Accept: application/json” http://httpbin.org/get

Using the “Accept: application/json” function does not guarantee that the response will be returned in JSON format. This is because the data format hugely relies on whether the target website supports JSON or not. 

Step 5: Following redirects

The next step involves following redirects- this occurs in some cases where the target URL redirects to another URL. However, cURL does not follow these redirects by default, but you can instruct it to do so with the -L or –location option as shown below:

curl -b “username=John” http://httpbin.org/cookies

Step 6: Sending cookies with a GET request

Many websites use cookies to track user activity. Therefore, you may need to send cookies with the GET request when you need to interact with such websites. Subsequently, the -b or 

-The cookie option can be used to achieve this, but you need to add the name and value of the cookie as shown below:

curl -b “username=John” http://httpbin.org/cookies

Troubleshooting Tips Associated with cURL GET Requests

Regardless of the numerous benefits associated with using cURL GET Requests, it is not uncommon to encounter some challenges. Here are some practical troubleshooting tips to help you deal with connectivity issues, misconfigurations, and others:

Check connection

The first practical troubleshooting tip is check your internet connection. If your device is not connected to the internet, then, you will get an error response. Firewalls, network issues, and proxy configuration have significant effects on how cURL interacts with external servers.

Confirm the URL and parameters

Another common troubleshooting tip is confirming the target URL, as well as the parameters in the cURL, GET Requests. Subsequently, you will receive an error response when you fail to double check the target website and encoded parameters.

Review server logs

For effective use of the cURL GET Requests, you need to examine the server logs. In simpler terms you need to review any misconfigurations or limitations that can affect its effectiveness. Therefore, cURL GET Requests provide a simple way of gathering valuable business insights. 

Import SSL/TLS

Another practical tip for using the cURL GET Requests is to import SSL /TLS. Ensure that you have downloaded and installed the LLS/TLS certificates, especially if your cURL request involves HTTPS. However, you may experience some challenges if cURL cannot identify the server’s certificate. You can use this code to verify if the server has required certification:

CURLOPT_SSL_VERIFYPEER 

CURLOPT_SSL_VERIFYHOST

Test the cURL command line

Before you venture into serious activities, you need to test the command line. This helps you determine if the command line is functional.

How to Handle Errors in cURL GET RequestsHow to Handle Errors in cURL GET Requests

Regardless of the program you are trying to build, error handling is a critical aspect of debugging to optimize the end-user experience. When using the cURL request, you can check for errors with cURL_error() and cURL_errno. Here are some tips to effectively manage errors associated with the cURL GET request:

Log errors

The first way to handle errors is to log them into a file or folder. This allows you to have a record, which is useful in tracking issues and diagnosing the problem to ensure efficiency.

Provide clear error messages

Provide clear and user-friendly messages when reporting on errors. However, be careful not to exploit sensitive information that can be exploited by malicious users.

Retry request

When developers encounter an error response, the first response is usually panic. However, this did not help the situation. Instead, you can use a retry mechanism for transient errors, especially in temporary situations like network glitches.

Exception handling

Exception handling is a crucial aspect of error handling. When implemented in your code, it can trigger centralized error handling in cases of cURL errors. However, the efficiency of this method depends on the structure of the program you are writing.

NetNut

Web scraping is one of the most common applications of the cURL GET request. Proxies is a must-have tool for web scraping and other online activities. Since there are several proxies in the market, choosing the best one can take time and effort.

NetNut is an industry-leading proxy provider with an extensive network of over 85 million rotating residential proxies in 200 countries and over 250,000 mobile IPS in over 100 countries, which helps them provide exceptional data collection services.

NetNut stands out for its user-friendly interface. In addition, we bill you for only the data you receive. If you want to enjoy ultra-fast data collection on demand, sign up for NetNut solutions. 

Moreover, we provide extensive documentation to help customers make the best choice regarding proxies. NetNut proxies come with a smart CAPTCHA bypass technology, which ensures your automated activities are not limited by these tests. 

Conclusion

We have examined the concept of cURL GET request, how it works, best practices, and how to troubleshoot common errors. Although cURL has a simple syntax, you still need to practice sending requests to become a professional. 

cURL is a powerful tool for performing GET requests and extracting data from APIs and web servers. Subsequently, cURL provides a simple yet efficient interface that allows you to interact with HTTP-based resources. 

Furthermore, you can streamline the cURL GET request with proxy integration. NetNut proxies allow you to access data from any corner of the world while bypassing geographical restrictions, CAPTCAHs, and browser fingerprinting for optimized security.

Contact us today to get started!

Frequently Asked Questions

What are the other types of cURL HTTP methods?

Here are some of the primary HTTP methods for cURL requests:

  • POST: This method sends data to the target server to create or update a resource. Most times, the POST method is used to upload files or submit form data ( -X POST)
  • DELETE makes a request for a specific resource to be erased (- X DELETE)
  • PUT is used to modify or replace an existing resource on a specified server. This method is idempotent, which means repeated requests do not have additional effects ( -X PUT) 
  • PATCH is used to make partial updates to a resource. It modifies only the specified parts of a resource ( -X PATCH)
  • HEAD is used to retrieve only the HTTP headers of a response. Since it excludes the body of a response, it is ideal for extracting metadata ( -l)
  • OPTIONS is used to describe the communication options for the target resource. Therefore, it helps determine which HTTP methods are supported by the servers ( -X OPTIONS)

What are the use cases of cURL GET Request?

Here are some popular applications of cURL GET request:

  1. Testing APIs: Since web scraping has become the order of the day, many websites offer APIs that allow you to access their data without putting a strain on the server’s resources. Therefore, cURL GET request is an excellent choice for sending test queries to APIs and reviewing the response.
  2. Web scraping: cURL GET request can be leveraged for extracting data from a website. It works by sending the HTTPS request and parsing the content with a scripting language.
  3. File downloads: cURL GET request is an excellent choice for downloading various things like documents or software indicated by the URL. 
  4. Website monitoring: You can monitor a website to access its functionality or track changes by scheduling the cURL GET request to retrieve some website elements at a predefined interval/

What are some of the cURL protocols?

Although cURL uses the HTTP protocol, it is also compatible with other protocols like:

  • The File Transfer Protocol (FTP) transfers files from a server to a client via this code: 

cURL -T [selected-file] “ftp://[target-destination]”

  • Simple Mail Transfer Protocol (SMTP) sends data to an SMTP server with this line of code:

cURL smtp://[smtp-sever] –mail-from [sender] –mail-rcpt \ [receiver] –upload-file [mail-content-file]

  • Dictionary Network Protocol offers access to dictionaries with the following command:

cURL “dict://dict.org/d:hello”

How to Send Get Requests With Curl- NetNut
Full Stack Developer
Ivan Kolinovski is a highly skilled Full Stack Developer currently based in Tel Aviv, Israel. He has over three years of experience working with cutting-edge technology stacks, including MEAN/MERN/LEMP stacks. Ivan's expertise includes Git version control, making him a valuable asset to NetNut's development team.