Name

rhosts − list of hosts that are logically equivalent to the local host

Syntax

/$HOME/.rhosts

Description

The .rhosts file allows a user who has an account on the local host to log in from a remote host without supplying a password.  It also allows remote copies to the local host.

If the .rhosts file exists, it is located in a user’s home directory. It is not a mandatory file, however.

The format of a .rhosts file entry is:

hostname [username]

The hostname is the name of the remote host from which the user wants to log into the local host.  The username is the user’s login name on the remote host.  If you do not specify a user name, the user must have the same login name on both the remote and local hosts. 

The host names listed in the .rhosts file may optionally contain the local BIND domain name.  For more information on BIND, see the Guide to the BIND/Hesiod Service. 

If a user ginger is logged in to host1, and wants to log in to a host called machine1 without supplying a password, she must:

•Have an account on machine1

•Create a .rhosts file in her home directory on machine1

•Specify host1 ginger as an entry in the .rhosts file. If ginger has the same login on both host1 and machine1, she can simply specify host1 in her .rhosts entry.

Note

You can allow the superuser of a remote system to log in to your system without password protection or perform a remote copy by having a .rhosts file in the root ( / ) directory, but it is not recommended.  In addition to having a .rhosts file, the superuser needs a secure terminal entry in the /etc/ttys file for each pseudoterminal configured in the system. The secure entry looks similar to the following:

ttyp3      none    network         secure

See the ttys() reference page for more information.

Examples

The following is a sample .rhosts file for the user ginger. It is located in her home directory on host1. She also has accounts on the hosts called machine1, system1, and host3. Her login name on machine1 and host3 is the same as on host1, but her login on system1 is gordon.

To enable ginger to log in to host1 from machine1, system1, and host3 without supplying a password, her .rhosts on host1 should contain the following entries:

machine1
system1  gordon
host3

See Also

hosts.equiv(5), ttys(5)
Introduction to Networking and Distributed System Services