scp

Copy a local file to a remote host

$ scp [path/to/local_file] [remote_host]:[path/to/remote_file]

$ scp -P [port] [path/to/local_file] [remote_host]:[path/to/remote_file]

$ scp [remote_host]:[path/to/remote_file] [path/to/local_directory]

$ scp -r [remote_host]:[path/to/remote_directory] [path/to/local_directory]

$ scp -3 [host1]:[path/to/remote_file] [host2]:[path/to/remote_directory]

$ scp [path/to/local_file] [remote_username]@[remote_host]:[path/to/remote_directory]

$ scp -i [~/.ssh/private_key] [path/to/local_file] [remote_host]:[path/to/remote_file]

$ scp -J [proxy_username]@[proxy_host] [path/to/local_file] [remote_host]:[path/to/remote_file]

scp [options] [[user@]host1:]file1 [[user@]host2:]file2

-p
    Preserves modification times, access times, and modes from the original file.

-q
    Suppresses progress meter and warning/diagnostic messages.

-r
    Recursively copy entire directories.

-v
    Verbose mode. Causes scp to print debugging messages about its progress.

-c cipher
    Selects the cipher to use for encrypting the data transfer. This option is directly passed to ssh.

-i identity_file
    Selects the file from which the identity (private key) for authentication is read. This option is directly passed to ssh.

-P port
    Specifies the port to connect to on the remote host. This option is directly passed to ssh.

-S program
    Name of program to use for the encrypted connection. The program must understand ssh(1) options.

[[user@]host1:]file1
    Source file specification. It can be a local file or a remote file in the format user@host:path.

[[user@]host2:]file2
    Destination file specification. It can be a local file or a remote file in the format user@host:path.

The scp (Secure Copy) command is a command-line utility that allows users to securely transfer files between a local host and a remote host, or between two remote hosts. It leverages the SSH (Secure Shell) protocol for secure data transfer, ensuring confidentiality and integrity. scp utilizes the same authentication and encryption mechanisms as SSH, protecting against eavesdropping and man-in-the-middle attacks.

It is a crucial tool for system administrators and developers for tasks such as deploying applications to remote servers, backing up data, or sharing files securely. It is simple and provides direct access from the command line, but is now considered legacy in favour of more advanced tools such as rsync, which offers additional features like delta transfers. Despite its age, it remains widely used for its simplicity and security features built on SSH.

scp relies on the underlying ssh subsystem for authentication and security. It's crucial to ensure that SSH is properly configured and secured. Also scp is deprecated in some environments in favor of sftp and other modern alternatives.

Copy a local file to a remote server:
scp localfile.txt user@remotehost:/path/to/destination/

Copy a remote file to the local machine:
scp user@remotehost:/path/to/remotefile.txt /local/destination/

Copy a directory recursively to a remote server:
scp -r localdirectory user@remotehost:/path/to/destination/

Always verify the fingerprint of the remote host to prevent man-in-the-middle attacks.
Use strong passwords or key-based authentication for SSH.
Ensure that the SSH server is properly configured and secured.

scp was originally developed as part of the OpenBSD project.
It was designed to provide a secure alternative to the insecure rcp command, leveraging the security features of SSH. scp became a standard tool for transferring files securely over networks, especially in Unix-like environments.
Over time, other more advanced tools like rsync and sftp have gained popularity, offering features such as resume functionality and more robust error handling. However, scp remains a widely used command due to its simplicity and wide availability.

ssh(1), sftp(1), rsync(1)