Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

rhosts(5) [ultrix man page]

rhosts(5)							File Formats Manual							 rhosts(5)

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


       The  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 file exists, it is located in a user's home directory.  It is not a mandatory file, however.

       The format of a 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 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 is logged in to and wants to log in to a host called without supplying a password, she must:

       o    Have an account on

       o    Create a file in her home directory on

       o    Specify host1 ginger as an entry in the file.
	    If has the same login on both and she can simply specify host1 in her entry.  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 file in the root ( / ) directory, but it is not recom-
	    In addition to having a file, the superuser needs a terminal entry in the file for each pseudoterminal configured in the system.   The
	    secure entry looks similar to the following:
	    ttyp3      none    network	       secure
	    See the reference page for more information.

       The  following is a sample file for the user It is located in her home directory on She also has accounts on the hosts called and Her login
       name on and is the same as on but her login on is

       To enable to log in to from and without supplying a password, her on should contain the following entries:
       system1	gordon

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


Check Out this Related Man Page

hosts.equiv(4)						     Kernel Interfaces Manual						    hosts.equiv(4)

hosts.equiv - A file containing the names of remote systems and users that can execute commands on the local system SYNOPSIS
/etc/hosts.equiv DESCRIPTION
The /etc/hosts.equiv file and the .rhosts file in a user's home directory contain the names of remote hosts and users that are equivalent to the local host or user. An equivalent host or user is allowed to access a local nonsuperuser account with the rsh command or rcp com- mand, or to log in to such an account without having to supply a password. The /etc/hosts.equiv file specifies equivalence for an entire system, while a user's .rhosts file specifies equivalence between that user and remote users. The local user and the target system exist in the same area as the hosts.equiv file. The .rhosts file must be owned by the user in whose home directory the file is located, or by the superuser. It cannot be a symbolic link. Each line, or entry, in hosts.equiv or .rhosts may consist of the following: A blank line. A comment (begins with a #). A host name (a string of any printable characters except newline, #, or white space). In addition, an NIS netgroup can be specified in place of the host name. A host name followed by white space and a user name. In addition, an NIS netgroup can be specified in place of the host name, user name, or both. A single plus (+) character. This means any host and user. The keyword NO_PLUS. This keyword disallows the use of the plus character (+) to match any host or user on a system-wide basis. By default, the line containing this keyword is a comment. Remove the com- ment character to disallow the use of the plus character. Entries in the hosts.equiv file are either positive or negative. Positive entries allow access; negative entries deny access. The following entries are positive: host name user name +@netgroup In addition, the plus sign (+) can be used in place of the host name or user name. In place of the host name, it means any remote host. In place of the user name, it means any user. The following entries are negative: -host name -user name -@netgroup To be allowed access or denied access, a user's remote host name and user name must match an entry in hosts.equiv or .rhosts. The hosts.equiv file is searched first; if a match is found, the search ends. Therefore, the order in which the positive and negative entries appear is important. If a match is not found, .rhosts is searched if it exists in the user's home directory. A host name or user name can match an entry in hosts.equiv in one of the following ways: The official host name (not an alias) of the remote host matches a host name in hosts.equiv. The remote user name matches a user name in hosts.equiv. If a user name parameter is included in the hosts.equiv file, this means that the remote user is a trusted user and is allowed to rlogin to any local user account without being prompted for a password. Otherwise, if the user name parameter is not specified in the hosts.equiv file, the name of the remote user must match that of the local user. If the remote user name does not match a user name in hosts.equiv, the remote user name matches the local user name. CAUTIONS
For security purposes, the files /etc/hosts.equiv and .rhosts should exist and be readable and writable only by the owner, even if they are empty. EXAMPLES
The following are sample entries in an /etc/hosts.equiv file: # Allows access to users on host1 and host2 that have accounts on this host: host1 host2 # Allows access to user johnson on host1 to any local user: host1 johnson # Allows access to all users on systems specified in netgroup chicago +@chicago # Denies access to users specified in netgroup finance on host5 host5 -@finance # Allows access to all users on all systems except root + -root RELATED INFORMATION
Commands: rcp(1), rlogin(1), rsh(1) Functions: ruserok(3). Files: netgroup(4) Daemons: rlogind(8), rshd(8) delim off hosts.equiv(4)
Man Page