ssh

ssh [options] hostname [command]

Securely log a user into a remote system and run commands on that system. The version of ssh described here is the OpenSSH client. ssh can use either Version 1 (SSH1) or Version 2 (SSH2) of the SSH protocol. SSH2 is preferable, as it provides stronger encryption methods and greater connection integrity. The hostname can be specified either as hostname or as user@hostname. If a command is specified, the user is authenticated, the command is executed, and the connection is closed. Otherwise, a terminal session is opened on the remote system. See Escape characters," later in this section, for functions that can be supported through an escape character. The default escape character is a tilde (~). The exit status returned from ssh is the exit status from the remote system, or 255 if there was an error.

Commonly, authentication is handled with standard username/password credentials, but it can also be useful to authenticate with a key exchange. This is done by generating a key on the client with ssh-keygen and populating the known_hosts file on the remote host.