# Cheatsheet & Examples: scp `scp` (secure copy) is a command-line utility used to securely transfer files and directories between a local host and a remote host or between two remote hosts. It uses the Secure Shell (SSH) protocol for secure data transfer, encrypting the data during transmission. ## Copying a file from local machine to a remote machine Example Usage: `scp /path/to/local/file username@remote_host:/path/to/remote/directory/` What it does: Copies a local file to a specified directory on a remote server. Command-line Arguments Explained: - `/path/to/local/file`: The local path to the file you want to copy. - `username@remote_host`: Specifies the remote user and host. The format is `username@hostname` or `username@IP_address`. You will be prompted for the user's password on the remote host. - `/path/to/remote/directory/`: The destination directory on the remote host. If the directory doesn't exist, `scp` won't create it, and the transfer will fail. The filename in the destination will be the same as the original. If you want a different filename on the remote end, specify the full path including the new filename: `/path/to/remote/directory/new_filename`. ## Copying a file from a remote machine to the local machine Example Usage: `scp username@remote_host:/path/to/remote/file /path/to/local/directory/` What it does: Copies a file from a specified location on a remote server to a local directory. Command-line Arguments Explained: - `username@remote_host`: Specifies the remote user and host. The format is `username@hostname` or `username@IP_address`. You will be prompted for the user's password on the remote host. - `/path/to/remote/file`: The path to the file on the remote server you want to copy. - `/path/to/local/directory/`: The local destination directory. The filename in the destination will be the same as the original. If you want a different filename, specify the full path including the new filename: `/path/to/local/directory/new_filename`. ## Copying a directory from local machine to a remote machine Example Usage: `scp -r /path/to/local/directory username@remote_host:/path/to/remote/directory/` What it does: Copies a directory and all its contents (recursively) from your local machine to a remote server. Command-line Arguments Explained: - `-r`: The recursive option. This tells `scp` to copy directories and their contents. - `/path/to/local/directory`: The local path to the directory you want to copy. - `username@remote_host`: Specifies the remote user and host. You will be prompted for the user's password on the remote host. - `/path/to/remote/directory/`: The destination directory on the remote host. The directory structure will be preserved. If the destination directory does not exist, it will be created. ## Copying a directory from a remote machine to the local machine Example Usage: `scp -r username@remote_host:/path/to/remote/directory /path/to/local/directory/` What it does: Copies a directory and all its contents (recursively) from a remote server to your local machine. Command-line Arguments Explained: - `-r`: The recursive option. This tells `scp` to copy directories and their contents. - `username@remote_host`: Specifies the remote user and host. You will be prompted for the user's password on the remote host. - `/path/to/remote/directory`: The path to the directory on the remote server you want to copy. - `/path/to/local/directory/`: The local destination directory. The directory structure will be preserved. If the destination directory does not exist, it will be created. ## Specifying a custom SSH port Example Usage: `scp -P 2222 username@remote_host:/path/to/remote/file /path/to/local/directory/` What it does: Copies a file from a remote host to the local machine, specifying a non-standard SSH port. Command-line Arguments Explained: - `-P 2222`: Specifies the port number to use for the SSH connection. In this example, it uses port 2222. - `username@remote_host`: Specifies the remote user and host. You will be prompted for the user's password on the remote host. - `/path/to/remote/file`: The path to the file on the remote server you want to copy. - `/path/to/local/directory/`: The local destination directory. The filename in the destination will be the same as the original. ## Using a private key for authentication Example Usage: `scp -i /path/to/private/key username@remote_host:/path/to/remote/file /path/to/local/directory/` What it does: Copies a file from a remote host to the local machine, authenticating using a private key file. Command-line Arguments Explained: - `-i /path/to/private/key`: Specifies the identity file (private key) to use for authentication. - `username@remote_host`: Specifies the remote user and host. No password prompt should appear if the key is configured correctly on the remote host. - `/path/to/remote/file`: The path to the file on the remote server you want to copy. - `/path/to/local/directory/`: The local destination directory. The filename in the destination will be the same as the original. ## Copying multiple files Example Usage: `scp file1.txt file2.txt username@remote_host:/path/to/remote/directory/` What it does: Copies multiple files from the local machine to a remote directory. Command-line Arguments Explained: - `file1.txt file2.txt`: List of the files to be copied. - `username@remote_host`: Specifies the remote user and host. You will be prompted for the user's password on the remote host. - `/path/to/remote/directory/`: The destination directory on the remote host. All files will be copied to this directory. The filenames will remain the same. ## Limiting bandwidth usage Example Usage: `scp -l 1024 /path/to/local/file username@remote_host:/path/to/remote/directory/` What it does: Copies a local file to a remote machine while limiting the bandwidth used. Command-line Arguments Explained: - `-l 1024`: Specifies the bandwidth limit in kilobits per second. In this example, it's set to 1024 kbps (1 Mbps). - `/path/to/local/file`: The local path to the file you want to copy. - `username@remote_host`: Specifies the remote user and host. You will be prompted for the user's password on the remote host. - `/path/to/remote/directory/`: The destination directory on the remote host. The filename will remain the same. ## Preserve modification times and access times Example Usage: `scp -p /path/to/local/file username@remote_host:/path/to/remote/directory/` What it does: Copies a local file to a remote machine, preserving the original modification and access times of the file. Command-line Arguments Explained: - `-p`: Preserves modification times, access times, and permissions of the file(s). - `/path/to/local/file`: The local path to the file you want to copy. - `username@remote_host`: Specifies the remote user and host. You will be prompted for the user's password on the remote host. - `/path/to/remote/directory/`: The destination directory on the remote host. The filename will remain the same.