SCP (Secure Copy Protocol) is a command-line utility for securely transferring files between Linux systems over SSH. Unlike the standard cp command which only works locally, SCP enables cross-server file operations with encryption.

Basic Command Syntax

scp [options] source_path destination_path

Commonly Used Parameters

• -r: Recursively copy directories and their contents
• -P: Specify port number (note uppercase P)
• -p: Preserve file attributes (timestamps, permissions)
• -C: Enable compression during transfer
• -v: Verbose output for debugging
• -q: Quiet mode (suppress progress output)

Practical Examples

1. Uploading Files too Remote Server

scp /local/path/file.txt user@remote_ip:/remote/path/

2. Uploading Entire Directory

scp -r /local/directory/ user@remote_ip:/remote/path/

3. Downloading Files from Remote Server

scp user@remote_ip:/remote/path/file.txt /local/path/

4. Downloading Entire Directory

scp -r user@remote_ip:/remote/directory/ /local/path/

Security Considerations

SCP uses SSH for all transfers, providing encryption for both authentication and data transfer. For additional security:

• Use SSH keys instead of password authentication
• Specify custom ports with -P if not using default SSH port
• Consider bandwidth limits with -l for large transfers