Transferring Multiple Files with SCP and SFTP

Secure Copy (SCP) and Secure File Transfer Protocol (SFTP) are widely used for transferring files securely over a network. While these tools are primarily designed for single file transfers, there are methods to transfer multiple files efficiently. In this tutorial, we will explore how to copy multiple files using SCP and SFTP with single commands, making it easier to manage batch file transfers.

Introduction to SCP

SCP is a protocol that allows secure file transfers between hosts on a network. It uses the same authentication and encryption mechanisms as SSH (Secure Shell), ensuring that data is protected from unauthorized access during transfer.

Copying Multiple Files with SCP

When you need to copy multiple files, using SCP can become cumbersome if done individually. However, there are several ways to simplify this process:

1. Using Braces {}: This method allows you to specify multiple files or directories in a single command. For example:

   scp [email protected]:/some/remote/directory/{a,b,c} ./
   

   This command copies files a, b, and c from the remote directory to your local directory.

2. Using Wildcards *: You can also use wildcards to copy multiple files that match a certain pattern.

   scp *.txt [email protected]:~
   

   This command copies all .txt files in your current directory to the remote host’s home directory.

3. Recursive Copy -r: If you have a whole directory you want to copy, including its subdirectories and files, use the -r option.

   scp -r ./dir-with-files user@remote-server:upload-path
   

   This command recursively copies all contents of ./dir-with-files to upload-path on the remote server.

Using SFTP for Multiple File Transfers

SFTP provides an alternative method for transferring files, especially useful when dealing with multiple files from different directories or when you need more control over the transfer process.

1. Interactive SFTP Session: You can start an interactive SFTP session and then use the get command to download files.

   sftp user@host
   sftp> get /some/remote/path1/file1 /some/local/path1/
   sftp> get /some/remote/path2/file2 /some/local/path2/
   sftp> quit
   

2. Batch Mode with Here Document: For automating transfers of multiple files, you can use a here document to input commands to SFTP.

   sftp user@host << EOF
   get /some/remote/path1/file1 /some/local/path1/
   get /some/remote/path2/file2 /some/local/path2/
   EOF
   

3. Batch Mode with a File: Alternatively, you can write your SFTP commands in a file and execute them using the -b option.

   sftp user@host -b batchFile.txt
   

Tips for Efficient Transfers

• Use Compression: If you’re transferring large files or many small ones, consider compressing them first to reduce transfer time. Tools like gzip, tar, and zip can be very helpful.
• Optimize Your Network Connection: The speed of your file transfers depends on your network connection. Ensure you have a stable and fast internet connection for optimal performance.
• Security First: Always prioritize security when transferring files over a network. Use secure protocols like SCP and SFTP, and keep your SSH keys and passwords safe.

Conclusion

Transferring multiple files securely over a network can be efficiently managed using SCP and SFTP. By understanding how to leverage the features of these tools, such as using braces for multiple file specifications, wildcards for pattern matching, and recursive copy options, you can simplify your workflow and ensure that your data is protected during transfer.