cURL, or Client URL, is a command-line tool that allows you to transfer data to and from servers. It supports many protocols, including FTP, HTTP, HTTPS, and more.
cURL can be used for many things, such as downloading files, uploading files, and sending data to APIs. In this article, we will explore different ways to use cURL to download files.
Features of cURL
Before we jump into the specifics of downloading files with cURL, let’s explore some of the features that make cURL a powerful tool. Protocols: cURL supports many protocols, such as FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, Telnet, and more.
This means that cURL can be used for many types of file transfers. Authentication: cURL can handle different types of authentication, such as Basic, Digest, and NTLM.
This means that you can access resources that require authentication. Encryption: cURL supports SSL and TLS encryption, which means that you can make secure connections to servers.
Proxy Server: cURL supports a proxy server, which means that you can use it to access resources that are behind a firewall. Interrupted Transfers: cURL is designed to handle interrupted transfers gracefully.
If a transfer is interrupted for any reason, cURL will try to resume the transfer from where it left off.
Installing cURL in Linux
cURL is free and open-source software, which means that you can download and use it for free. Here’s how to install cURL in Linux:
1.
Open a terminal window. 2.
Type the following command: sudo apt-get install curl
3. Press Enter.
4. Enter your password (if prompted).
5. Press Enter.
Downloading Files Using cURL
Now that cURL is installed, let’s start downloading files. We will explore different ways to download files using cURL.
Basic Download Command
The simplest way to download a file with cURL is to use the -O parameter. This parameter tells cURL to save the downloaded file with the same name as the remote file.
Here’s the basic syntax to download a file with cURL:
curl -O [remote_file_url]
For example, to download a file from a website, you would type the following command:
curl -O https://example.com/file.zip
This will download the file and save it in the current working directory with the same name as the remote file.
Downloading Multiple Files
If you want to download multiple files with cURL, you can use the -O flag followed by the file names. For example, if you want to download three files, you would type the following command:
curl -O file1.zip -O file2.zip -O file3.zip [remote_file_url]
This will download the three files and save them in the current working directory with the same names as the remote files.
Customizing File Name and Path
If you want to customize the name and path of the downloaded file, you can use the -o flag followed by the file name and path. For example, if you want to download a file and save it in a different directory with a different name, you would type the following command:
curl -o /path/to/custom_file_name.zip [remote_file_url]
Resuming Interrupted Downloads
As mentioned earlier, cURL is designed to handle interrupted transfers gracefully. If a transfer is interrupted, cURL will try to resume the transfer from where it left off.
To resume an interrupted download, you can use the -C- flag followed by the URL. For example, if you want to resume an interrupted download, you would type the following command:
curl -C- -O [remote_file_url]
This will resume the interrupted download and save the file in the current working directory.
Using Proxy Server
If you want to use a proxy server to download a file, you can use the -x flag followed by the proxy URL. For example, if you want to download a file using a proxy server, you would type the following command:
curl -x [proxy_url] -O [remote_file_url]
This will download the file using the specified proxy server.
Conclusion
cURL is a powerful tool that can be used for many things, including downloading files. In this article, we explored different ways to use cURL to download files.
We learned about the features of cURL, such as protocols, authentication, encryption, proxy server, and interrupted transfers. We also saw how to install cURL in Linux and how to use cURL to download files with different options.
Uploading Files Using cURL in Linux
cURL is widely known for its file transfer capabilities, which allow users to download files from servers. However, cURL can also be used to upload files to servers.
In this article, we will explore how to upload files using cURL in Linux.
Uploading files via FTP without credentials
The most basic way to upload a file to an FTP server using cURL is without credentials. This may be useful in cases where the FTP server allows anonymous uploads.
The command to upload a file without credentials is:
curl -T [/path/to/local/file] ftp://[remote_server_url]/[remote_directory]/[remote_filename]
For example, if the remote server URL is ftp://example.com and the remote directory is /upload/ and the remote filename is new_file.txt, you would use the following command:
curl -T /home/user/Desktop/new_file.txt ftp://example.com/upload/new_file.txt
This will upload the local file to the remote FTP server at the specified directory and with the specified filename.
Uploading files via FTP with credentials
If the FTP server requires credentials to upload a file, you can use the -u flag to specify the login credentials. The command to upload a file to an FTP server with login credentials is:
curl -u [username:password] -T [/path/to/local/file] ftp://[remote_server_url]/[remote_directory]/[remote_filename]
For example, if the username is ‘user’ and the password is ‘password’, the remote server URL is ftp://example.com, the remote directory is /upload/, and the remote filename is new_file.txt, you would use the following command:
curl -u user:password -T /home/user/Desktop/new_file.txt ftp://example.com/upload/new_file.txt
This command will upload the file to the specified directory on the FTP server with the specified filename.
Uploading files via HTTP
In addition to FTP, cURL also supports file uploads via the HTTP protocol. You can use various external file-sharing services to upload your files, such as ‘https://transfer.sh’.
The command to upload a file via HTTP is:
curl –upload-file [/path/to/local/file] https://transfer.sh/[remotefilename]
For example, if the local file path is /home/user/Desktop/new_file.txt and you want to name the remote file my_file.txt, you would use the following command:
curl –upload-file /home/user/Desktop/new_file.txt https://transfer.sh/my_file.txt
This command will upload the file to the specified remote filename on the servers like https://transfer.sh.
Conclusion
In conclusion, using cURL in Linux, you can upload files to servers regardless of the protocols. We explored two ways of uploading files to an FTP server using cURL, with both anonymous and login requirements.
Additionally, we saw how to upload files via HTTP, which is useful for using various web file-sharing platforms. cURL supports many transfer protocols, which makes it a cross-platform tool due to its availability on multiple operating systems.
It is also essential when using file-sharing services to perform file transfers or backups. In conclusion, cURL is a versatile and powerful tool that allows users to download and upload files over various protocols.
We explored how to upload files using cURL in Linux, including uploading files to an FTP server with and without login credentials, and uploading files via HTTP. With cURL, users can easily and reliably transfer files across platforms and use external file-sharing services.
Whether downloading or uploading files, cURL proves to be a useful tool that streamlines file transfers and can help take your work to the next level.