Secure File Copies

SSH is, for the most part, a remakably secure and robust way to perform necessary tasks on a remote machine, and to do so as if you were actually working locally. Despite some recently discovered security holes, SSH remains the standard for secure remote access.

The OpenSSH distribution also has the advantage of bundling a program called scp. Since you’re probably getting a good feel for naming conventions in Linux, I’m sure I won’t have to tell you that scp stands for [s]ecure [c]op[p]y. And, it’s an aptly named program. scp allows you to utilize the security of SSH to copy files from a remote machine to your local box.

Much like SSH, scp is remarkably easy to use. To copy a file from the /home/tony directory on the machine located at IP address 255.255.255.255 to the home directory on your local machine, you’d simply invoke the command:

    scp 255.255.255.255:/home/tony/file /home/tony

This command opens a secure shell to 255.255.255.255, crawls into the /home/tony directory, and copies the file file to the /home/tony directory on the local machine.

If the machine from which you’re copying the file is listed in your /etc/hosts file, you’ll be able to use the name of that machine rather than its IP address. When this command is completed, the secure shell is closed and you’re returned to your local machine.

Tomorrow, we’ll wrap up this mini-series on networking programs in Linux with a summary and some final thoughts.