Secure Copy

The scp (Secure Copy) command is used to securely transfer files between a local host and a remote host, or between two remote hosts, over SSH. Here’s a quick guide to get you started with scp:

Basic Syntax

scp [options] <source> <destination>

<source>: The file or directory you want to copy. <destination>: The location where you want to copy the file or directory.

Common Use Cases

Copy a file from local machine to remote server:

Write permission is needed.

scp /path/to/local/file user@remote:/path/to/remote/directory

Example:

scp /home/user/file.txt user@remote:/home/user/destination/

This copies file.txt from your local machine to the remote machine at /home/user/destination/.

Copy a file from remote server to local machine:

Read permission is needed.

scp user@remote:/path/to/remote/file /path/to/local/directory

Example:

scp user@remote:/home/user/file.txt /home/localuser/destination/

This copies file.txt from the remote server to your local machine.

Copy a directory recursively (use the -r option):

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

Example:

scp -r /home/user/folder user@remote:/home/user/destination/

This copies the entire folder from your local machine to the remote server.

Copy a file from one remote server to another remote server:

scp user1@remote1:/path/to/file user2@remote2:/path/to/destination

Example:

scp user1@remote1:/home/user1/file.txt user2@remote2:/home/user2/destination/

This copies a file from remote1 to remote2.

Useful Options:
-r: Copy directories recursively.
-P <port>: Specify a non-default SSH port (if the remote server uses a custom port).

scp -P 2222 file.txt user@remote:/path/to/destination/

-i <identity_file>: Use a specific private key file for SSH authentication.

Need to create the key and add public key to server.

ssh-keygen -t ed25519 -C "my_key" -f /path/to/private_key
ssh-copy-id -i /path/to/private_key.pub user@remote

scp -i /path/to/private_key file.txt user@remote:/path/to/destination/

Example Scenarios:

Copy file from local to remote:

scp myfile.txt user@192.168.1.10:/home/user/

Copy directory from local to remote:

scp -r mydir/ user@192.168.1.10:/home/user/

Copy file from remote to local:

scp user@192.168.1.10:/home/user/myfile.txt /home/localuser/

Copy between two remote servers:

scp user@remote1:/path/to/file.txt user@remote2:/path/to/destination/