Rlogin

rlogin is one of the BSD "r" commands (e.g., rlogin, rsh, rcp).

These commands allow access to, or the execution of commands on, remote systems. For example, if one is on a network, and you log into machine foo, and bar is on the network also, one can, from foo, log in to bar by using rlogin: rlogin bar which will not prompt you for a password again. This may be useful in case bar has a different environment or operating system you want to test something under.

If either a .rhost file exists in the users home directory on the target system, or a /etc/hosts.equiv file exists on the target system and contains the hostname of the system the request for access originates from, then the remote access is provided without further authentication.

Because of the inherent security issues of allowing unauthenticated access, system administrators on multiuser systems will often have cron launched utilities that search out and remove .rhost or hosts.equiv files.

rlogin has been all but made obsolete by ssh, which provides password-less logins in a safe manner using cryptography and a program ssh-agent.