In Unix, how do I use the scp command to securely transfer files between two computers?

In Unix, you can use the scp command to copy files and directories securely between remote hosts without starting an FTP session or logging into the remote systems explicitly. The scp command uses SSH to transfer data, so it requires a password or passphrase for authentication. Unlike rcp or FTP, scp encrypts both the file and any passwords exchanged so that anyone "snooping" on the network can't view them.

Warning: Be careful when copying between hosts files that have the same names; you may accidently overwrite them.

The syntax for the scp command is as follows: scp [options] [[user@]host1:]filename1 ... [[user@]host2:]filename2 For example, if user dvader is on a computer called empire.gov, and wants to copy a file called file1.txt to a directory called somedir in his account on a computer called deathstar.com, he would enter the following: scp file1.txt dvader@deathstar.com:somedir Likewise, if he wanted to copy the entire contents of the somedir directory on deathstar.com back to his empire.gov account, he would enter: scp -r dvader@deathstar.com:somedir somedir Similarly, if he is working on another computer, but wanted to copy a file called file1.txt from his home directory on empire.gov to a directory called somedir in his account on deathstar.com, he would enter: scp dvader@empire.gov:file1.txt dvader@deathstar.com:somedir

When using wildcards (e.g.,  *  and  ? ) to copy multiple files from a remote system, be sure to enclose the filenames in quotes. This is because the Unix shell, not the scp command, expands unquoted wildcards.

For more information about scp, consult its man page. At the Unix prompt, enter: man scp

Also see:

• In Unix, what is rcp, and how do I use it?
• In SSH and SSH2 for Unix, how do I set up public key authentication?
• For Unix, what are ssh-agent and ssh-add, and how do I use them?